A Series of Unfortunate Omelettes: Lithium in Food Review & Survey Proposal

One thing that makes lithium a plausible explanation for the obesity epidemic is that clinical doses of lithium cause weight gain as a side-effect. A clinical dose of lithium is in the range of 1000 mg (“300 mg to 600 mg … 2 to 3 times a day”), and people pretty reliably gain weight on doses this high. In a 1976 review of case records, about 60% of people gained weight on clinical doses, with an average weight gain of about 10 kg.

But those are clinical doses, and it seems like the doses you’re getting from the environment are generally much smaller. There’s usually some lithium in modern drinking water, and there’s more lithium in drinking water now than there used to be. It seems to get into the water supply from things like drilled water wells, fracking, and fossil fuel prospecting, transport, and disposal. But even with all these sources of contamination, the dose you’re getting from your drinking water is relatively low, probably not much more than 0.2 mg per day. If you live right downstream from a coal plant, or you’re chugging liter bottles of mineral water on the regular, you could maybe get 5 or 10 mg/day. But no one is getting 1000 mg/day or even 300 mg/day from their drinking water. 

So what gives? 

Effects of Trace Doses

One possibility is that small amounts of lithium are enough to cause obesity, at least with daily exposure.

This is plausible for a few reasons. There’s lots of evidence (or at least, lots of papers) showing psychiatric effects at exposures of less than 1 mg (see for example meta-analysis, meta-analysis, meta-analysis, dystopian op-ed). If psychiatric effects kick in at less than 1 mg per day, then it seems possible that the weight gain effect would also kick in at less than 1 mg. 

There’s also the case study of the Pima in the 1970s. The Pima are a group of Native Americans who live in the American southwest, particularly around the Gila River Valley, and they’re notable for having high rates of obesity and diabetes much earlier than other groups. They had about 0.1 mg/L in their water by the 1970s (which was 50x the national median at the time), for a dose of only about 0.2-0.3 mg per day, and were already about 40% obese. All this makes the trace lithium hypothesis seem pretty reasonable.

Unfortunately, no one knows where the weight gain effects of lithium kick in. As far as we can tell, there’s no research on this question. It might cause weight gain at doses of 10 mg, or 1 mg, or 0.1 mg. Maybe 0.5 mg a week on average is enough to make some people really obese. We just don’t know.

Some people in the nootropics community take lithium, often in the form of lithium orotate (they use orotate rather than other compounds because it’s available over-the-counter), as part of their stacks. Based on community posts like this, this, and this, the general doses nootropics enthusiasts are taking are in the range of 1-15 mg per day. 

We haven’t done a systematic review of the subreddit (but maybe you should, that would be a good project for someone) but they seem to report no effects or mild positive effects at 1 or 2 mg lithium orotate and brain fog and fatigue at 5 mg lithium orotate and higher. Some of them report weight gain, even on doses this low. The fact that a couple extra mg might be enough to push you over the line suggests that the weight gain tipping point is somewhere under 10 mg, maybe a lot under. And for what it’s worth, all of this is consistent with the only randomized controlled trial examining the effects of trace amounts of lithium which found results at just 0.4 mg a day. 

Clinical and Subclinical Doses

Another possibility is that people really ARE getting unintended clinical doses of lithium. We see two reasons to think that this might be possible.

#1: Doses in the Mirror may be…

The first is that clinical doses are smaller than they appear. 

When a doctor prescribes you lithium, they’re always giving you a compound, usually lithium carbonate (Li2CO3). Lithium is one of the lightest elements, so by mass it will generally be a small fraction of any compound it is part of. A simple molecular-weight calculation shows us that lithium carbonate is only about 18.7% elemental lithium. So if you take 1000 mg a day of lithium carbonate, you’re only getting 187.8 mg/day of the active ingredient.

The little purple orbs are the pharmacologically active lithium ions, everything else is non-therapeutic carbonate

For bipolar and similar disorders, lithium carbonate has become such a medical standard that people usually just refer to the amount of the compound. It’s very unusual for an ion to be a medication, so this nuance is one that some doctors/nurses don’t notice. It’s pretty easy to miss. In fact, we missed it too until we saw this reddit comment from u/PatienceClarence/, which begins, “First off we need to differentiate between the doses of lithium orotate vs elemental lithium. For example, my dosage was 130 mg orotate which would give me 5 mg ‘pure’ lithium…” 

Elemental lithium is what we really care about, and when we look at numbers from the USGS or serum samples or whatever, they’re all talking about elemental lithium. When we say people get 0.1 mg/day from their water, or when we talk about getting 3 mg from your food, that’s milligrams of elemental lithium. When we say that your doctors might give you 600 mg per day, that’s milligrams lithium carbonate — and only 112.2 milligrams a day of elemental lithium. With this in mind, we see that the dose of elemental lithium is always much lower than the dose as prescribed. 

A high clinical dose is 600 mg lithium carbonate three times a day (for a total of 1800 mg lithium carbonate or about 336 mg elemental lithium), but many people get clinical doses that are much smaller than this. Low doses seem to be more like 450 mg lithium carbonate per day (about 84 mg/day elemental lithium) or even as little as 150 mg lithium carbonate per day (about 28 mg/day elemental lithium).

Once we take the fact that lithium is prescribed as a compound into account, we see that the clinical dosage is really closer to something like 300 mg/day for a high dose and 30 mg/day for a low dose. So at this point we just need to ask, is it possible that people might occasionally be getting 30 mg/day or more lithium in the course of their everyday lives? Unfortunately we think the answer is yes.

#2: Concentration in Food

The other reason to think that modern people might be getting clinical or subclinical doses on the regular is that there’s clear evidence that lithium concentrates in some foods. 

Again, consider the Pima. The researchers who tested their water in the 1970s also tested their crops. While most crops were low in lithium, they found that one crop, wolfberries, contained an incredible 1,120 mg/kg.

By our calculations, you could easily get 15 mg of lithium in a tablespoon of wolfberry jelly. If the Pima ate one tablespoon a day, they would be getting around 100 times more lithium from that tablespoon than they were getting from their drinking water.

The wolfberries in question (Lycium californium) are a close relative of goji berries (Lycium barbarum or Lycium chinense). The usual serving size of goji berries is 30 grams, which if you were eating goji berries like the ones the Pima were eating, would provide about 33.6 mg of lithium. This already puts you into clinical territory, a little more than someone taking a 150 mg tablet of lithium carbonate.

If you had a hankering and happened to eat three servings of goji berries in one day, you would get just over 100 mg of lithium from the berries alone. We don’t know how much people usually eat in one go, but it’s easy enough to buy a pound (about 450 g) of goji berries online. We don’t have any measurements of how much lithium are in the goji berries you would eat for a snack, but if they contained as much lithium as the wolfberries in the Gila River Valley, the whole 1 lb package would contain a little more than 500 mg of lithium.

So. Totally plausible that some plants concentrate 0.1 mg/L lithium in water into 1,120 mg/kg in the plant, because Sievers & Cannon have measurements of both. Totally plausible that you could get 10 or even 100 mg if you’re eating a crop like this. So now we want to know, are there other crops that concentrate lithium? And if so, what are they?

In this review, we take a look at the existing literature and try to figure out how much lithium there is in different foods. What crops does it concentrate in? Is there any evidence that foods are further contaminated in processing or transport? There isn’t actually all that much work on these questions, but we’ll take a look at what we can track down.

Let’s not bury the lede: we find evidence of subclinical levels of lithium in several different foods. But most of the sources that report these measurements are decades old, and none of them are doing anything like an exhaustive search. That’s why at the end of this piece, we’re going to talk a little bit about our next project, a survey of lithium concentrations in foods and beverages in the modern American food supply.

Because of this, our goal is not to make this post an exhaustive literature review; instead, our goal is to get a reasonable sense of how much lithium is in the food supply, and where it is. When we do our own survey of modern foods, what should we look at first? This review is a jumping off point for our upcoming empirical work.

Context for the Search

But first, a little additional context. 

There are a few official estimates of lithium consumption we should consider (since these are in food and water, all these numbers should be elemental lithium). This review paper from 2002 says that “the U.S. Environmental Protection Agency (EPA) in 1985 estimated the daily Li intake of a 70 kg adult to range from [0.650 to 3.100 mg].” The source they cite for this is “Saunders, DS: Letter: United States Environmental Protection Agency. Office of Pesticide Programs, 1985”, but we can’t find the original letter. As a result we don’t really know how accurate this estimate is, but it suggests people were getting about 1-3 mg per day in 1985.

These numbers are backed up by some German data which appear originally to be from a paper from 1991, which we will discuss more in a bit: 

In Germany, the individual lithium intake per day on the average of a week varies between [0.128 mg/day] and [1.802 mg/day] in women and [0.139] and [3.424 mg/day] in men. 

The paper also includes histograms of those distributions: 

Both of these say “mg/day” but we’re pretty sure that’s 1000x too high and they should say “µg/day”. If it were mg/day we think many of these people would be dead?

We want to call your attention to the shape of both of these distributions, because the shape is going to be important throughout this review. Both distributions are pretty clearly lognormal, meaning they peak early on but then have a super long tail off to the right. For example, most German men in this study were getting only about 0.2 to 0.4 mg of lithium per day, but twelve of them were getting more than 1 mg a day, and five of them were getting more than 2 mg a day. At least one person got more than 3 mg a day. And this paper is looking at a pretty small group of Germans. If they had taken a larger sample, we would probably see a couple people who were consuming even more. You see a similar pattern for women, just at slightly lower doses.

We expect pretty much every distribution we see around food and food exposure to be lognormal. The amount people consume per day should usually be lognormally distributed, like we see above. The distribution of lithium in any foods and crops will be lognormal. So will the distribution of lithium levels in water sources. For example, lithium levels in that big USGS dataset of groundwater samples we always talk about are distributed like this:

With scatterplot because those outliers are basically invisible on the histogram

Again we see a clear lognormal distribution. Most groundwater samples they looked at had less than 0.2 mg/L lithium. But five had more than 0.5 mg/L and two had more than 1 mg/L.

This is worth paying close attention to, because when a variable is lognormally distributed, means and medians will not be very representative. For example, in the groundwater distribution you see above, the median is .0055 mg/L and the mean is .0197 mg/L. 

These sound like really tiny amounts, and they are! But the mean and the median do not tell anywhere close to the full story. If we keep the long tail of the distribution in mind, we see that about 4% of samples contain more than 0.1 mg/L, about 1% of samples contain more than 0.2 mg/L, and of course the maximum is 1.7 mg/L. 

This means that about 4% of samples contain more than 20x the median, about 1% of samples contain more than 40x the median, and the maximum is more than 300x the median.

Put another way, about 4% of samples contain more than 5x the mean, about 1% of samples contain more than 10x the mean, and the maximum is more than 80x the mean.

We should expect similar distributions everywhere else, and we should expect means and medians to consistently be misleading in the same way. So if we find a crop with 1 mg/kg of lithium on average, that suggests that the maximum in that crop might be as high as 80 mg/kg! If this math is even remotely correct, you can see why crops that appear to have a low average level of lithium might still be worth empirically testing.

Another closely related point: that USGS paper only found those outliers because it’s a big survey, 4700 samples. Small samples will be even more misleading. Let’s imagine the USGS had taken a small number of samples instead. Here are some random sets of 6 observations from that dataset:

0.044, 0.007, 0.005, 0.036, 0.001, 0.002

0.002, 0.028, 0.005, 0.001, 0.009, 0.001

0.003, 0.006, 0.002, 0.001, 0.001, 0.006

We can see that small samples ain’t representative. If we looked at a sample of six US water sources and found that all of them contained less than 0.050 mg/L of lithium, we would miss that some US water sources out there contain more than 0.500 mg/L. In this situation, there’s no substitute for a large sample size (or, the antidote is to be a little paranoid about how long the tail is).

So if we looked at a sample of (for example) six lemons, and found that all of them contained less than 10 mg/kg of lithium, we might easily be missing that there are lemons out there that contain more than 100 mg/kg.

In any case, the obvious lognormal distribution fits really well with the kind of bolus-dose explanation we discussed with JP Callaghan, who said: 

My thought was that bolus-dosed lithium (in food or elsewhere) might serve the function of repeated overfeeding episodes, each one pushing the lipostat up some small amount, leading to overall slow weight gain. … I totally vibe with the prediction that intake would be lognormally distributed. … lognormally distributed doses of lithium with sufficient variability should create transient excursions of serum lithium into the therapeutic range.

In the discussion with JP Callaghan, we also said:

Because of the lognormal distribution, most samples of food … would have low levels of lithium — you would have to do a pretty exhaustive search to have a good chance of finding any of the spikes. So if something like this is what’s happening, it would make sense that no one has noticed. 

What we’re saying is that even if people aren’t getting that much lithium on average, if they sometimes get huge doses, that could be enough to drive their lipostat upward. If we take that model seriously, the average amount might not not be the real driver, and we should focus on whether there are huge lithium bombs out there, and how often you might encounter them. Or it could be even more complicated! Maybe some foods give you repeated moderate doses, and others give you rare megadoses. 

Two final notes before we start the review: 

First, if two sources disagree — one says strawberries are really high in lithium and the other says that strawberries are really low in lithium, or something — we should keep in mind that disagreement might mean something like “the strawberries were grown in different conditions (i.e. one batch was grown in high-lithium soil and the other batch wasn’t)” or even “apparently identical varieties of strawberries concentrate lithium differently”. There isn’t a simple answer to simple-sounding questions like “how much lithium is in a strawberry” because reality is complicated and words make it easy to hide that complexity without thinking about it.

Second, we want to remind you that whatever dose causes obesity, lithium is also a powerful sedative with well-known psychiatric effects. If you’re getting doses up near the clinical range, it’s gonna zonk you out and probably stress your kidneys. 

Ok. What crops concentrate lithium?

Lithium Concentration

Unfortunately we couldn’t find several of the important primary sources, so in a number of places, we’ve had to rely on review papers and secondary sources. We’re not going to complain “we couldn’t find the primary source” every time, but if you’re ever like “why are they citing a review paper instead of the original paper?” this is probably why.

We should warn you that these sources can be a little sloppy. Important tables are labeled unclearly. Units are often given incorrectly, like those histograms above that say mg/day when they should almost certainly say µg/day. When you double-check their citations, the numbers don’t always match up. For example, one of the review papers said that a food contained 55 mg/kg of lithium. But when we double-checked, their source for that claim said just 0.55 mg/kg in that food. So we wish we were working with all the primary sources but we just ain’t. Take all these numbers with a grain of salt.

Particularly important modern reviews include Lithium toxicity in plants: Reasons, mechanisms and remediation possibilities by Shahzad et al. (2016), Regional differences in plant levels and investigations on the phytotoxicity of lithium by Franzaring et al. (2016), and Lithium as an emerging environmental contaminant: Mobility in the soil-plant system by Robinson et al. (2018). Check those out if you finish this blog post and you want to know more.

It’s worth noting just how concerned some of these literature reviews sound. Shahzad et al. (2016) say in their abstract, “The contamination of soil by Li is becoming a serious problem, which might be a threat for crop production in the near future. … lack of considerable information about the tolerance mechanisms of plants further intensifies the situation. Therefore, future research should emphasize in finding prominent and approachable solutions to minimize the entry of Li from its sources (especially from Li batteries) into the soil and food chain.”

Older reviews include The lithium contents of some consumable items by Hullin, Kapel, and Drinkall — a 1969 paper which includes a surprisingly lengthy review of even older sources, citing papers as far back as 1917. Sadly we weren’t able to track down most of these older sources, and the ones we could track down were pretty vague. Papers from the 1930s just do not give all that much detail. Still, very cool to have anything this old. 

There’s also Shacklette, Erdman, Harms, and Papp (1978), Trace elements in plant foodstuffs, a chapter from (as far as we can tell) a volume called “Toxicity of Heavy Metals in the Environment”, which is part of a series of reference works and textbooks called “HAZARDOUS AND TOXIC SUBSTANCES”. It was sent to us by a very cool reader who refused to accept credit for tracking it down. If you want to see this one, email us.

A bunch of the best and most recent information comes from a German fella named Manfred Anke, who published a bunch of papers on lithium in food in Germany in the 1990s and 2000s. He did a ton of measurements, so you will keep seeing his name throughout. Unfortunately the papers we found from Anke mostly reference measurements from earlier work he did, which we can’t find. Sadly he is dead so we cannot ask him for more detail.

From Anke, in case anyone can track them down, we’d especially like to see a couple papers from the 1990s. Here they are exactly as he cites them:  

Anke’s numbers are very helpful, but we think they are a slight underestimation of what is in our food today. We’re pretty sure lithium levels in modern water are higher than levels in the early 1990s, and we’re pretty sure lithium levels are higher in US water than in water in Germany. In a 2005 paper, Anke says: “In Germany, the lithium content of drinking water varies between 4 and 60 µg/L (average : 10 µg/L).” Drinking water in the modern US varies between undetectable and 1700 µg/L (1.7 mg/L), and even though that 1700 is an outlier, about 8% of US groundwater samples contain more than 60 µg/L, the maximum Anke gives for Germany. The mean for US groundwater is 19.7 µg/L, compared to the 10 µg/L Anke reports.

So the smart money is that Anke’s measurements are probably all lower than the levels in modern food, certainly lower than the levels in food in the US.

Here’s another thing of interest: in one paper Anke estimates that in 1988 Germany, the average daily lithium intake for women was 0.373 mg, and the average daily lithium intake for men was 0.432 mg (or something like that; it REALLY looks like he messed up labeling these columns, luckily the numbers are all pretty similar). By 1992, he estimates that the average daily lithium intake for women was 0.713 mg, and the average daily lithium intake for men was 1.069 mg. He even explicitly comments, saying, “the lithium intake of both sexes doubled after the reunification of Germany and worldwide trade.”

That last bit about trade suggests he is maybe blaming imported foods with higher lithium levels, but it’s not really clear. He does seem to think that many foreigners get more lithium than Germans do, saying, “worldwide, a lithium intake for adults between [0.660 and 3.420 mg/day] is calculated.”

Anyways, on to actual measurements.

Beverages

Beverages are probably not giving you big doses of lithium, with a few exceptions.

Most drinking water doesn’t contain much lithium, rarely poking above 0.1 mg/L. Some beverages contain more, but not a lot more. The big exception, no surprise, is mineral water.

As usual, Anke and co have a lot to say. The Anke paper from 2003 says, “cola and beer deliver considerable amounts of lithium for humans, and this must be taken into consideration when calculating the lithium balance of humans.” The Anke paper from 2005 says that “amounts of [0.002 to 5.240 mg/L] were found in mineral water. Like tea and coffee, beer, wine and juices can also contribute to the lithium supply.” But the same paper reports a range of just 0.018 – 0.329 mg/L in “beverages”. Not clear where any of these numbers come from, or why they mention beer in particular — the citation appears to be the 1995 Anke paper we can’t find. 

In fact, Anke seems to disagree with himself. The 2005 paper mentions tea and coffee contributing to lithium exposure. But the 2003 paper says, “The total amount in tea and coffee, not their water-soluble fraction in the beverage, was registered. Their low lithium content indicates that insignificant amounts of lithium enter the diet via these beverages.”

This 2020 paper, also from Germany, finds a weak relationship for beer and wine and a strong relationship for tea with plasma concentrations for lithium. We think there are a lot of problems with this method (the serum samples are probably taken fasted, and lithium moves through the body pretty quickly) but it’s interesting.

Franzaring et al. (2016), one of those review papers, has a big figure summarizing a bunch of other sources, which has this to say about some beverages: 

For water, 1 ppm is approximately 1 mg/L

So obviously mineral water can contain a lot — if you drank enough, you could probably get a small clinical dose from mineral water alone. On the other hand, who’s drinking a liter of mineral water? Germans, apparently.

We think their sources for wine are Classification of wines according to type and region based on their composition from 1987 and Classification of German White Wines with Certified Brand of Origin by Multielement Quantitation and Pattern Recognition Techniques from 2004. The 1987 paper reports average levels of lithium in Riesling and Müller-Thurgau wines in the range of about 0.010 mg/L, and a maximum of only 0.022 mg/L. The 2004 paper looks at several German white wines, and reports a maximum of 0.150 mg/L. This is pretty unsystematic but does seem to indicate an increase. 

This paper from 2000 similarly finds averages of 0.035 and 0.019 mg/L in red wines from northern Spain. This 1994 paper and this 1997 paper both report similar values. We also found this 1988 paper looking at French red wines which suggests a range from 2.61 to 17.44 mg/L lithium. Possibly this was intended to be in µg/L instead of in mg/L? “All results are in milligrams per liter except Li, which is in micrograms per liter” is a disclaimer we’ve seen in more than one of these wine papers.

So it might be good to check, but overall we don’t think you’ll see much more than 0.150 mg/L in your wine, and most of you are hopefully drinking less than a full liter at a time.

She’s just so happy!

The most recent and most comprehensive source for beverages, however, is a 2020 paper called Lithium Content of 160 Beverages and Its Impact on Lithium Status in Drosophila melanogaster. Forget the Drosophila, let’s talk about all those beverages. This is yet another German paper, and they analyzed “160 different beverages comprising wine and beer, soft and energy drinks and tea and coffee infusions … by inductively coupled plasma mass spectrometry (ICP-MS).” And unlike other sources, they give all the numbers — If you want to know how much lithium they found in Hirschbraeu/Adlerkoenig, “Urtyp, hell” or the cola known as “Schwipp Schwapp”, you can look that up. 

They find that, aside from mineral water, most beverages in Germany contain very little lithium. Concentration in wine, beer, soft drinks, and energy drinks was all around 0.010 mg/L, and levels in tea and coffee barely ever broke 0.001 mg/L.

The big outlier is the energy drink “Acai 28 Black, energy”, which contained 0.105 mg/L. This is not a ton in the grand scheme of things — it’s less than some sources of American drinking water — but it’s a lot compared to the other beverages in this list. They mention, “it has been previously reported that Acai pulp contains substantial concentrations of other trace elements, including iron, zinc, copper and manganese. In addition to acai extract, Acai 28 black contains lemon juice concentrate, guarana and herb extracts, which possibly supply Li to this energy drink.”

BEWARE

We want to note that beverages in America may contain more lithium, just because American drinking water contains more lithium than German drinking water does. But it’s doubtful that people are getting much exposure from beverages beyond what they get from the water it’s made with. 

Basic Foods

We also have a few leads on what might be considered “basic” or “component” foods.

Anke mentions sugars a bit, though doesn’t go into much detail, saying, “honey and sugar are also extremely poor in lithium…. The addition of sugar apparently leads to a further reduction of the lithium content in bread, cake, and pastries.“ At one point he lists the range of “Sugar, honey” as being 0.199 – 0.527 mg/kg, with a mean of 0.363 mg/kg. That’s pretty low.

We also have a little data from the savory side. This paper from 1969 looked at levels in various table salts, finding (in mg/kg):

On the one hand, those are relatively high levels of lithium. On the other hand, who’s eating a kilogram of salt? Even if table salt contains 3 mg/kg, you’re just never gonna get even close to getting 1 mg from your salt.

Plant-Based Foods

It’s clear that plants can concentrate lithium, and some plants concentrate lithium more than others. It’s also clear that some plants concentrate lithium to an incredible degree. This last point is something that is emphasized by many of the reviews, with Shahzad et al. (2016) for example saying, “different plant species can absorb considerable concentration [sic] of Li.” 

Plant foods have always contained some lithium. The best estimate we have for preindustrial foods is probably this paper that looked at foods in the Chocó rain forest around 1970, and found (in dry material): 3 mg/kg in breadfruit; 1.5 mg/kg in cacao, 0.4 mg/kg in coconut, 0.25 mg/kg in taro, 0.4 mg/kg in yam, 0.6 mg/kg in cassava, 0.5 mg/kg in plantain fruits, 0.1 mg/kg in banana, 0.3 mg/kg in rice, 0.01 mg/kg in avocado, 0.5 mg/kg in dry beans, and 0.05 mg/kg in corn grains. Not nothing, but pretty low doses overall.

There are a few other old sources we can look at. Shacklette, Erdman, Harms, and Papp (1978) report a paper by Borovik-Romanova from 1965, in which she “reported the Li concentration in many plants from the Soviet Union to range from 0.15 to 5 [mg/kg] in dry material; she reported Li in food plants as follows ([mg/kg] in dry material): tomato, 0.4; rye, 0.17; oats, 0.55; wheat, 0.85; and rice, 9.8.” That’s a lot in rice, but we don’t know if that’s reliable, and we haven’t seen any other measurements of the levels in rice. We weren’t able to track the Borovik-Romanova paper down, unfortunately.

From here, we can try to narrow things down based on the better and more modern measurements we have access to.

Cereals

We haven’t seen very much about levels in cereals / grains / grass crops, but what we have seen suggests very low levels of accumulation.

Hullin, Kapel, and Drinkall (1969) mention an earlier review which found that the Gramineae (grasses) were especially “poor in lithium”, giving a range of 0.47-1.07 mg/kg. 

Borovik-Romanova reported, in mg/kg, “rye, 0.17; oats, 0.55; wheat, 0.85; and rice, 9.8” in 1965 in the USSR. Most of these concentrations are very low. Again, rice is abnormally high, but this measurement isn’t at all corroborated. And since we haven’t been able to find this primary source, there’s a good chance it should read 0.98 instead.

Anke, Arnhold, Schäfer, & Müller (2005) report levels from 0.538 to 1.391 mg/kg in “cereal products”, and in a 2003 paper, say “the different kinds of cereals grains are extremely lithium-poor as seeds.” Anke reports slightly lower levels in derived products like “bread, cake”. 

There’s also this unusual paper on corn being grown hydroponically in solutions containing various amounts of lithium. They find that corn is quite resistant to lithium in its water, actually growing better when exposed to some lithium, and only seeing a decline at concentrations around 64 mg/L. (“the concentration in solution ranging from 1 to 64 [mg/L] had a stimulating effect, whereas a depression in yielding occurred only at the concentrations of 128 and 256 [mg/L].”) But the plant also concentrates lithium — even when only exposed to 1 mg/L in its solution, the plant ends up with an average of about 11 mg/kg in dry material. Unfortunately they don’t seem to have measured how much ends up in the corn kernels, or maybe they didn’t let the corn develop that far. Seems like an oversight. (Compare also this similar paper from 2012.)

Someone should definitely double-check those numbers on rice to be safe, and corn is maybe a wildcard, but for now we’re not very worried about cereal crops.

Leafy Vegetables

A number of sources say that lithium tends to accumulate in leaves, suggesting lithium levels might be especially high in leafy foods. While most of us are in no danger of eating kilograms of cabbage, it’s worth looking out for. 

In particular, Robinson et al. (2018) observed significant concentration in the leaves of several species as part of a controlled experiment. They planted beetroot, lettuce, black mustard, perennial ryegrass, and sunflower in controlled environments with different levels of lithium exposures. “When Li was added to soil in the pot experiment,” they report, “there was significant plant uptake … with Li concentrations in the leaves of all plant species exceeding 1000 mg/kg (dry weight) at Ca(NO3)2-extractable concentrations of just 5 mg/kg Li in soil, representing a bioaccumulation coefficient of >20.” For sunflowers in particular, “the highest Li concentrations occurred in the bottom leaves of the plant, with the shoots, roots and flowers having lower concentrations.”

Obviously this is reason for concern, but these are plants grown in a lab, not grown under normal conditions. We want to check this against actual measurements in the food supply. 

Hullin, Kapel, and Drinkall (1969) report that an earlier source, Bertrand (1943), “found that the green parts of lettuce contained 7.9 [mg/kg] of lithium.” They wanted to follow up on this surprisingly high concentration, so they tested some lettuce themselves, finding: 

This pretty clearly contradicts the earlier 7.9 mg/kg, though the fact that lettuce can contain up to 2 mg/kg is still a little surprising. This could be the result of lettuce being grown in different conditions, the lognormal distribution, etc., but even so it’s reassuring to see that not all lettuce in 1969 contained several mg per kg.

In this study from 1990, the researchers went and purchased radish, lettuce and watercress at the market in Brazil, and found relatively high levels in all of them:

Let’s also look at this modern table that reviews a couple more recent sources, from Shahzad et al.:

FW = Fresh Weight and DM = Dry Matter, we think? 

None of these are astronomical, but it’s definitely surprising that spinach contains more than 4 mg/kg and celery and chard both contain more than 6 mg/kg, at least in these measurements.

So not to sound too contrarian but, maybe too many leafy greens are bad for your health. 

Fruits & Non-Leafy Veggies

Anke, Arnhold, Schäfer, & Müller (2005) say that “fruits and vegetables supply 1.0 to 7.0 mg Li/kg,” and report levels from 0.383 to 6.707 mg/kg in fruits. 

This is a wide range, and a pretty high ceiling. But as usual, Anke is much vaguer than we might hope. He gives some weird hints, but no specific measurements. In the 2003 paper, Anke says, “as a rule, fruits contain less lithium than vegetative parts of plants (vegetables). Lemons and apples contained significantly more lithium, with about 1.4 mg/kg dry matter, than peas and beans.”

More specific numbers have been hard to come by. We’ve found a pretty random assortment, like how Shahzad et al. report that “in a hydroponic experiment, Li concentration in nutrient solution to 12 [mg/L], increased cucumber fruit yield, fruit sugar, and ascorbic acid levels, but Li did not accumulate in the fruit (Rusin, 1979).” It’s interesting that cucumbers survive just fine in water containing up to 12 mg/L, and that suggests that lithium shouldn’t accumulate in cucumbers under any realistic water levels. But cucumbers are not a huge portion of the food supply.

What we do see all the time is sources commenting on how citrus plants are very sensitive to lithium. Anke says, “citrus trees are the most susceptible to injury by an excess of lithium, which is reported to be toxic at a concentration of 140–220 p.p.m. in the leaves.” Robinson et al. (2018) say, “citing numerous sources, Gough et al. (1979) reported a wide variation in plant tolerance to Li; citrus was found to be particularly sensitive, whilst cotton was more tolerant.” Shahzad et al. say, “Bradford (1963) found reduced and stunted growth of citrus in southern California, U.S.A., with the use of highly Li-contaminated water for irrigation. …  Threshold concentrations of Li in plants are highly variable, and moderate to severe toxic effects at 4–40 mg Li kg−1 was observed in citrus leaves (Kabata-Pendias and Pendias, 1992).” This Australian Water Quality Guidelines for Fresh and Marine Waters document says, “except for citrus trees, most crops can tolerate up to 5 mg/L in nutrient solution (NAS/NAE 1973). Citrus trees begin to show slight toxicity at concentrations of 0.06–0.1 mg/L in water (Bradford 1963). Lithium concentrations of 0.1–0.25 mg/L in irrigation water produced severe toxicity symptoms in grapefruit … (Hilgeman et al. 1970)”.

All tantalizing, but we can’t get access to any of those primary sources. For all we know this is a myth that’s been passed around the agricultural research departments since the 1960s.

The citrus is tantalizing, get it? 

Even if citrus trees really are extra-sensitive to lithium, it’s not clear what that means for their fruits. Maybe it means that citrus fruits are super-low in lithium, since the tree just dies if it’s exposed to even a small amount. Or maybe it means that citrus fruits are super-high in lithium — maybe citrus trees absorb lithium really quickly and that’s why lithium kills them at relatively low levels.

So it’s interesting but at this point, the jury is out on citrus.

Nightshades

Multiple sources mention that the Solanaceae family, better known as nightshades, are serious concentrators of lithium. Hullin, Kapel, and Drinkall mention that even in the 1950s, plant scientists were aware that nightshades are often high in lithium. Anke, Schäfer, & Arnhold (2003) mention, “Solanaceae are known to have the highest tolerance to lithium. Some members of this family accumulate more than 1000 p.p.m. lithium.” Shacklette, Erdman, Harms, and Papp (1978) even mention a “stimulating effect of Li as a fertilizer for certain species, especially those in the Solanaceae family.”

Shahzad et al. (2016) say, “Schrauzer (2002) and Kabata-Pendias and Mukherjee (2007) noted that plants of Asteraceae and Solanaceae families showed tolerance against Li toxicity and exhibited normal plant growth,” and, “some plants of the Solanaceae family, when grown in an acidic climatic zone accumulate more than 1000 mg/kg Li.” We weren’t able to track down most of their sources for these claims, but we did find Schrauzer (2002). He mentions that Cirsium arvense (creeping thistle) and Solanum dulcamara (called things like fellenwort, felonwood, poisonberry, poisonflower, scarlet berry, and snakeberry; probably no one is eating these!) are notorious concentrators of lithium, and he repeats the claim that some Solanaceae accumulate more than 1000 mg/kg lithium, but it’s not clear what his source for this was.

Hullin, Kapel, and Drinkall mention in particular one source from 1952 that found a range of 1.8-7.96 [mg/kg] in members of the Solanaceae. 7.9 mg/kg in some nightshades is enough to be concerned, but they don’t say which species this measurement comes from. 

The finger seems to be pointing squarely at the Solanaceae — but which Solanaceae? This family is huge. If you know anything about plants, you probably know that potatoes and tomatoes are both nightshades, but you may not know that nightshades also include eggplants, the Capsicum (including e.g. chili peppers and bell peppers), tomatillos, some gooseberries, the goji berry, and even tobacco. 

We’ve already seen how wolfberries / goji berries can accumulate crazy amounts under the right circumstances, which does make this Solanaceae thing seem even more plausible. 

Anke, Schäfer, & Arnhold (2003) mention potatoes in particular in one section on vegetable foods, saying: “All vegetables and potatoes contain > 1.0 mg lithium kg−1 dry matter.” There isn’t much detail, but the paper does say, “peeling potatoes decreases their lithium content, as potato peel stores more lithium than the inner part of the potato that is commonly eaten.”

That same paper that tries to link diet to serum lithium levels does claim to find that a diet higher in potatoes leads to more serum lithium, but we still think this paper is not very good. If you look at table 4, you see that there’s not actually a clear association between potatoes and serum levels. Table 5 says that potatoes come out in a regression model, but it’s a bit of an odd model and they don’t give enough detail for us to really evaluate it. And again, these serum concentrations were taken fasted, so they didn’t measure the right thing.

It’s much better to just measure the lithium in potatoes directly. Anke seems to have done this in the 1990s, but he’s not giving any details. We’ll have to go back all the way to 1969, when Hullin, Kapel, and Drinkall included three varieties of potatoes in their study (numbers in mg/kg):

These potatoes, at least, are pretty low in lithium. The authors do specifically say these were peeled potatoes, which may be important in the light of Anke’s comment about the peels. These numbers are pretty old, and modern potatoes probably are exposed to more lithium. But even so, these potatoes do not seem to be mega-concentrators, and Hullin, Kapel, and Drinkall did find some serious concentrators even back in 1969. 

This is especially interesting to us because it provides a little support for the idea that the potato diet might cause weight loss by reducing your lithium intake and forcing out the lithium already in your system with a high dose of potassium, or something. At the very least, it looks like you’d get less lithium in your diet if you lived on only potatoes than if you somehow survived on only lettuce (DO NOT TRY THE LETTUCE DIET).

Apparently the nightshade family’s tendency to accumulate lithium does not include the potatoes (unless the peeling made a huge difference?). This suggests that the high levels might have come from some OTHER nightshade. Obviously we have already seen huge concentrations in the goji berry (or at least, a close relative). But what about other nightshades, like tomatoes, eggplant, or bell peppers? 

Hullin, Kapel, and Drinkall do frustratingly say, “[The lithium content] of the tomato will be reported elsewhere.” But they don’t discuss it beyond that, at least not in this paper. We’ll have to look to other sources.

Shacklette et al. report: “Borovik-Romanova reported the Li concentration in [dry material] … tomato, 0.4 [mg/kg].” This is not much, though these numbers are from 1965, and from the USSR.

A stark contrast can be found in one of Anke’s papers, where they state, “Fruits and vegetables supply 1.0 to 7.0 mg Li/kg food DM. Tomatoes are especially rich in Li (7.0 mg Li/kg DM).” 

This is a lot for a vegetable fruit! It occurs to us that tomatoes are pretty easy to grow hydroponically, and you could just dose distilled water with a known amount of lithium. If any of you are hydroponic gardeners and want to try this experimentally, let us know! 

But tomatoes are obviously beaten out by wolfberries/goji berries, and they also can’t compare to this dark horse nightshade: tobacco.

SURPRISE

That’s right — Hullin, Kapel, and Drinkall (1969) also measured lithium levels in tobacco. They seem to have done this not because it’s another nightshade, but because previous research from the 1940s and 1950s had found that lithium concentrations in tobacco were “extraordinarily high”. For their own part, Hullin and co. found (mg/kg in ash): 

This is a really interesting finding, and in a crop we didn’t expect people to examine, since tobacco isn’t food.

At the same time, measuring ash is kind of cheating. Everything organic will be burned away in the cigarette or pipe, so the level of any salt or mineral will appear higher than it was in the original substance. As a result, we don’t really know the concentration in the raw tobacco. This is also the lithium that’s left over in the remnants of tobacco after it’s been smoked, so these measurements are really the amount that was left unconsumed, which makes it difficult to know how much might have been inhaled. Even so, the authors think that “the inhalation of ash during smoking could provide a further source of this metal”. 

This is also interesting in combination with the fact that people with psychiatric disorders often seem to self-medicate with tobacco. Traditionally schizophrenics are the ones drawn to being heavy smokers, but smoking is disproportionately common in bipolar patients as well. Researchers have generally tried to explain this in terms of nicotine, which we think of as being the active ingredient in tobacco, but given these lithium levels, maybe psychiatric patients smoke so much because they’re self-medicating with the lithium? Or maybe lithium exposure through the lungs causes schizophrenia and bipolar disorder? (For comparison, see Scott Alexander discussing a similar idea.)  

We didn’t find measurements for any other nightshades, but we hope to learn more in our own survey.

Animal-Based Foods

Pretty much everything we see suggests that animal products contain more lithium on average than plant-based foods. This makes a lot of general sense because of biomagnification. It also makes particular sense because many food animals consume huge quantities of plant stalks and leaves, and as we’ve just seen, stalks and leaves tend to accumulate more lithium than other parts of the plants.

toxic waste make bear sad

But the bad news is that, like pretty much everything else, levels in animal products are poorly-documented and we have to rely heavily on Manfred Anke again. He’s a good guy, we just wish — well we wish we had access to his older papers.

It’s like he’s toying with us!!!

Meat

Meat seems to contain a consistently high level of lithium. Apparently based on measurements he took in the 1990s, Anke calculates that meat products contain an average of about 3.2 mg/kg, and he gives a range of 2.4 to 3.8 mg/kg. 

In Anke, Arnhold, Schäfer, & Müller (2005) he elaborates just a little, saying, “Poultry, beef, pork and mutton contain lithium concentrations increasing in that order.”

In place of more detailed measurements, Anke, Schäfer, & Arnhold (2003) give us this somewhat difficult paragraph: 

On average, eggs, meat, sausage, and fish deliver significantly more lithium per kg of dry matter than most cereal foodstuffs. Eggs, liver, and kidneys of cattle had a mean lithium content of 5 mg/kg. Beef and mutton contain more lithium than poultry meat. Green fodder and silage consumed by cattle and sheep are much richer in lithium than the cereals largely fed to poultry. Sausage and fish contain similar amounts of lithium to meat. 

Beyond this, we haven’t found much detail to report. And even Anke can’t keep himself from mentioning how meat plays second fiddle to something else:

… Poultry, beef, pork and mutton contain lithium concentrations increasing in that order. Most lithium is delivered to humans by eggs and milk (> 7000 µg/kg DM). 

This is backed up by Hullin, Kapel, and Drinkall (1969), who said: 

Among foods of animal origin, those which have been found to contain lithium include eggs (Press, 1941) and milk (Wright & Papish, 1929; Drea, 1934).

So let’s leave meat behind for now and look at the real heavy-hitters.

Dairy

The earliest report we could find for milk was this 1929 Science publication mentioned by Hullin, Kapel, and Drinkall. But papers this old are pretty terse. It’s only about three-quarters of a page, and the only information they give about lithium is that it is included in the “elements not previously identified but now found to be present” in milk. 

Anke can do one better, and estimates an average for “Milk, dairy products” of 3.6 mg/kg with a range of 1.1 to 7.5 mg/kg. This suggests that the concentration in dairy products is pretty high across the board, but also that there’s considerable variation.

Anke explains this in a couple ways. First of all, he says that there were, “significant differences between the lithium content of milk”, and he suggests that milk sometimes contained 10 mg/kg in dry matter. This seems to contradict the range he gives above, but whatever. 

He also points out that other dairy products contain less lithium. For example, he says that butter is “lithium-poor”, containing only about 1.2 mg/kg dry matter, which seems to be the bottom of the range for dairy. “In contrast to milk,” he says, “curd cheese and other cheeses only retain 20–55% of lithium in the original material available for human nutrition. The main fraction of lithium certainly leaves cheese and curd cheese via the whey.”

This is encouraging because we love cheese and we are glad to know it is not responsible for poisoning our brains — at least, not primarily. It’s also interesting because 20-55% is a pretty big range; we’d love to know if some cheeses concentrate more than others, or if this is just an indication of the wide variance he mentioned earlier in milk. Not that we really need it, but if you have access to the strategic cheese reserve, we’d love to test historical samples to see if lithium levels have been increasing. 

What he suggests about whey is also pretty intriguing. Whey is the main byproduct of turning milk into cheese, so if cheese is lower in lithium than milk is, then whey must be higher. Does this mean whey protein is super high in lithium?

Whey protein display in The Hague, flanked by boars

Eggs

The oldest paper we could find on lithium in eggs is a Nature publication from 1941 called “Spectrochemical Analysis of Eggs”, and it is half a page of exactly that and nothing else. They do mention lithium in the eggs, but unfortunately the level of detail they give is just: “Potassium and lithium were also present [in the eggs] in fair quantity.”

Anke gives his estimate as always, but this time, it’s a little different: 

Anke gives an average (we think; he doesn’t label this column anywhere) of 7.3 mg/kg in eggs. This is a lot, more than any other food category he considers. And instead of giving a range, like he does for every other food category, he gives the standard deviation, which is 6.5 mg/kg.

This is some crazy variation. Does that mean some eggs in his sample contained more than 13.8 mg/kg lithium? That’s only one standard deviation above the average, two standard deviations would be 20.3 mg/kg. A large egg is about 50 g, so at two standard deviations above average, you could be getting 1 mg per egg. 

That does seem to be what he’s suggesting. But if we assume the distribution of lithium in eggs is normal, we get negative values quickly, and an egg can’t contain a negative amount of lithium.

Because lithium concentrations can’t be negative, and because of the distributions we’ve seen in all the previous examples, we assume the distribution of lithium in eggs must be lognormal instead.

A lognormal distribution with parameters [1.7, .76] has a mean and sd of very close to 7.3 and 6.5, so this is a reasonable guess about the underlying distribution of eggs in Germany in 1991.

Examination of the lognormal distribution with these parameters suggests that the distribution of lithium in eggs (at least in Germany in 1991) looks something like this: The modal egg in this distribution contains about 3 mg/kg lithium. But about 21% of the eggs in this distribution contain more than 10 mg/kg lithium. About 4% contain more than 20 mg/kg. About 1% contain more than 30 mg/kg. About 0.4% contain more than 40 mg/kg. And two out of every thousand contain 50 mg/kg lithium or more. 

That’s a lot of lithium for just one egg. What about the lithium in a three-egg omelette? 

ACHTUNG

To answer this Omelettenproblem, we started by taking samples of three eggs from a lognormal distribution with parameters [1.7, .76]. That gives us the concentration in mg/kg for each egg in the omelette.

Again, a large egg is about 50 grams. In reality a large egg is slightly more, but we’ll use 50 g because some restaurants might use medium eggs, and because it’s a nice round number. 

So we multiply each egg’s mg/kg value by .05 (because 50 g out of 1000 g for a kilogram) to get the lithium it contains in mg, and we add the lithium from all three eggs in that sample together for the total amount in the omelette.

We did this 100,000 times, ending up with a sample of 100,000 hypothetical omelettes, and the estimated lithium dose in each. Here’s the distribution of lithium in these three-egg omelettes in mg as a histogram: 

And here it is as a scatterplot in the style of The Economist

As you can see, most omelettes contained less than 3 mg lithium. In fact, most contained between 0.4 and 1.6 mg.

This doesn’t sound like a lot, but we think it’s pretty crazy. A small clinical dose is something like 30 mg, and it’s nuts to see that you can get easily like 1/10 that dose from a single omelette. Remember that in 1985, the EPA estimated that the daily lithium intake of a 70 kg US adult ranged from 0.650 to 3.1 mg — but by 1991 Germany, you can get that whole dose in a single sitting, from a single dish! 

Even Anke estimated that his German participants were getting no more than 3 mg a day from their food. But this model suggests that you can show up at a cafe and say “Kellner, bringen Sie mir bitte ein Omelette” and easily get that 3 mg estimate blown out of the water before lunchtime.

Even this ignores the long tail of the data. The omelettes start to peter out at around 5 mg, but the highest dose we see in this set of 100,000 hypothetical breakfasts was 11.1 mg of lithium in a single omelette.

The population of Germany in 1990 was just under 80 million people. Let’s say that only 1 out of every 100 people orders a three-egg omelette on a given day. This means that every day in early 1990s Germany, about 800,000 people were rolling the dice on an omelette. Let’s further assume that the distribution of omelettes we generated above is correct. If all these things are true, around 8 unlucky people every day in 1990s Germany were getting smacked with 1/3 a clinical dose of lithium out of nowhere. It’s hard to imagine they wouldn’t feel that. 

Processed Food

One thing we didn’t see much of in this literature review was measurements of the lithium in processed food.

We’re very interested in seeing if processing increases lithium. But no one seems to have measured the lithium in a hamburger, let alone a twinkie. 

There are a few interesting things worth mentioning, however — all from Anke, Schäfer, & Arnhold (2003), of course.

Mostly Anke and co find that processed foods are not extreme outliers. “Ready-to-serve soups with meat and eggs were [rich] in lithium,” they say, “whereas various puddings, macaroni, and vermicelli usually contained < 1 mg lithium/kg dry matter. Bread, cake, and pastries are usually poor sources of lithium. On average, they contained less lithium than wheat flour. The addition of sugar apparently leads to a further reduction of the lithium content in bread, cake, and pastries.”

Even in tasty treats, they don’t find much. We don’t know how processed German chocolate was at the time, but they say, “the lithium content of chocolates, chocolate candies, and sweets amounted to about 0.5 mg/kg dry matter. Cocoa is somewhat richer in lithium. The addition of sugar in chocolates reduces their lithium content.”

The only thing that maybe jumps out as evidence of contamination from processing is what they say about mustard. “Owing to the small amounts used in their application,” they begin, “spices do not contribute much lithium to the diet. It is surprising that mustard is relatively lithium-rich, with 3.4 mg/kg dry matter, whereas mustard seed contains extremely little lithium.” Mustard is generally a mixture of mustard seed, water, vinegar, and not much else. We saw in the section on beverages that wine doesn’t contain much lithium, so vinegar probably doesn’t either. Maybe the lithium exposure comes from processing?

Misc

We notice that for many categories of food, we seem to have simply no information. How much lithium is in tree nuts? Peanuts? Melons? Onions? Various kinds of legumes? How much is in major crops like soy? This is part of why we need to do our own survey, to fill these gaps and run a more systematic search.

It’s interesting, though not surprising, to see such a clear divide between plant and animal foods. In fact, we wonder if this can explain why vegetarian diets seem to lead to a little weight loss and vegan diets seem to lead to a little more, and also why neither of them work great.

Meat seems to contain a lot of lithium, but honestly not that much more than things like tomatoes and goji berries. Vegetarians will consume less lithium when they stop eating meat, but if they compensate for not eating meat by eating more fruit, they might actually be worse off. If they compensate by eating more eggs, or picking up whey protein, they’re definitely worse off! 

Vegans have it a little better — just by being vegan, they’ll be cutting out the three most reliable sources of lithium in the general diet. As long as they don’t increase their consumption of goji berries to compensate, their total exposure should go down. Hey, it makes more sense than “not eating dairy products gives you psychic powers because otherwise 90% of your brain is filled with curds and whey.”

But even so, a vegan can get as much lithium as a meat-eater if they consume tons of nightshades, so even a vegan diet is not a sure ticket to lithium removal. Not to mention that we have basically no information on plant-based protein sources (legumes, nuts) so we don’t know how much lithium vegans might get from that part of their diet.

In Conclusion

There’s certainly lithium in our food, sometimes quite a bit of lithium. It seems like most people get at least 1 mg a day from their food, and on many days, there’s a good chance you’ll get more.

That said, most of the studies we’ve looked at are pretty old, and none of them are very systematic. Sources often disagree; sample sizes are small; many common foods haven’t been tested at all. The overall quality is not great. We don’t think any of this data is good enough to draw strong conclusions from. Personally we’re avoiding whey protein and goji berries for right now, but it’s hard to get a sense of what might be a good idea beyond that. So as the next step in this project, we’re gonna do our own survey of the food supply.

The basic plan is pretty simple. We’re going to go out and collect a bunch of foods and beverages from American grocery stores. As best as we can, we will try to get a broad and representative sample of the sorts of foods most people eat on a regular basis, but we’ll also pay extra-close attention to foods that we suspect might contain a lot of lithium. Samples will be artificially digested (if necessary) and their lithium concentration will be measured by ICP-MS. All results will be shared here on the blog.

Luckily, we have already secured funding for the first round of samples, so the survey will proceed apace. If you want to offer additional support, please feel free to contact us — with more funding, we could do a bigger survey and maybe even do it faster. We could also get a greenhouse and run some hydroponic studies maybe.

If you’re interested in getting involved in other ways, here are a few things that would be really helpful:

1. If you would be willing to go out and buy an egg or whatever and mail it in to be tested, so we could get measurements from all over the country / the world, please fill out this form.

2. If you work at the FDA or a major food testing lab or Hood Milk or something, or if you’re a grad student with access to the equipment to test your breakfast for lithium and an inclination to pitch in, contact phil@whylome.org to discuss how you might be able to contribute to this project.

Every Bug is Shallow if One of Your Readers is an Entomologist

The Cathedral and the Bazaar is an essay/book about how Linus Torvalds threw all the normal rules of software out the window when he wrote the operating system Linux

Back in the day, people “knew” that the way to write good software was to assemble an elite team of expert coders and plan things out carefully from the very beginning. But instead of doing that, Linus just started working, put his code out on the internet, and took part-time help from whoever decided to drop by. Everyone was very surprised when this approach ended up putting out a solid operating system. The success has pretty much continued without stopping — Android is based on Linux, and over 90% of servers today run a Linux OS.

Before Linux, most people thought software had to be meticulously designed and implemented by a team of specialists, who could make sure all the parts came together properly, like a cathedral. But Linus showed that software could be created by inviting everyone to show up at roughly the same time and place and just letting them do their own thing, like an open-air market, a bazaar.

Let’s consider in particular Chapter 4, Release Early, Release Often. One really weird thing Linus did was he kept putting out new versions of the software all the time, sometimes more than once a day. New versions would go out with the paint still wet, no matter how much of a mess they were.

People found this confusing. They thought putting out early versions was bad policy, “because early versions are almost by definition buggy versions and you don’t want to wear out the patience of your users.” Why the hell would you put out software if it were still crawling with bugs? Well,

Linus was behaving as though he believed something like this:

> Given a large enough beta-tester and co-developer base, almost every problem will be characterized quickly and the fix obvious to someone.

Or, less formally, “Given enough eyeballs, all bugs are shallow.” I dub this: “Linus’s Law”.

This bottom-up method benefits from two key advantages: the Delphi Effect and self-selection.

More users find more bugs because adding more users adds more different ways of stressing the program. This effect is amplified when the users are co-developers. Each one approaches the task of bug characterization with a slightly different perceptual set and analytical toolkit, a different angle on the problem. The “Delphi effect” seems to work precisely because of this variation. In the specific context of debugging, the variation also tends to reduce duplication of effort.

So adding more beta-testers may not reduce the complexity of the current “deepest” bug from the developer’s point of view, but it increases the probability that someone’s toolkit will be matched to the problem in such a way that the bug is shallow to that person.

One special feature of the Linux situation that clearly helps along the Delphi effect is the fact that the contributors for any given project are self-selected. An early respondent pointed out that contributions are received not from a random sample, but from people who are interested enough to use the software, learn about how it works, attempt to find solutions to problems they encounter, and actually produce an apparently reasonable fix. Anyone who passes all these filters is highly likely to have something useful to contribute.

Linus’s Law can be rephrased as “Debugging is parallelizable”. Although debugging requires debuggers to communicate with some coordinating developer, it doesn’t require significant coordination between debuggers. Thus it doesn’t fall prey to the same quadratic complexity and management costs that make adding developers problematic.

In practice, the theoretical loss of efficiency due to duplication of work by debuggers almost never seems to be an issue in the Linux world. One effect of a “release early and often” policy is to minimize such duplication by propagating fed-back fixes quickly.

Research is difficult because reality is complex and many things are confusing or mysterious. But with enough eyeballs, all research bugs are shallow too.

Without a huge research budget and dozens of managers, you won’t be able to coordinate a ton of researchers. But the good news is, you didn’t really want to coordinate everyone anyways. You can just open the gates and let people get to work. It works fine for software!

The best way to have troubleshooting happen is to let it happen in parallel. And the only way to make that possible is for everyone to release early and release often. If you sit on your work, you’re only robbing yourself of the debugging you could be getting for free from every interested rando in the world. 

In the course of our obesity research, we’ve talked to water treatment engineers, social psychologists, software engineers, emeritus diabetes researchers, oncologists, biologists, someone who used to run a major primate lab, multiple economists, entrepreneurs, crypto enthusiasts, physicians from California, Germany, Austria, and Australia, an MD/PhD student, a retired anthropologist, a mouse neuroscientist, and a partridge in a pear tree a guy from Scotland

Some of them contributed a little; some of them contributed a lot! Every one had a slightly different toolkit, a different angle on the problem. Bugs that were invisible to us were immediate and obvious to them, and each of them pointed out different things about the problem.

For example, in our post recruiting for the potato diet community trial, we originally said that we weren’t sure how Andrew Taylor went a year without supplementing vitamin A, and speculated that maybe there was enough in the hot sauces he was using. But u/alraban on reddit noticed that Andrew included sweet potatoes in his diet, which are high in vitamin A. We totally missed this, and hadn’t realized that sweet potatoes are high in vitamin A. But now we recommend that people either eat some sweet potato or supplement vitamin A. We wouldn’t have caught this one without alraban.

In another discussion on reddit, u/evocomp challenged us to consider the Pima, a small ethnic group in the American southwest that were about 50% obese well before 1980, totally bucking the global trend. “What’s the chance that [this] population … [is] highly sensitive and equally exposed to Lithium, PFAS, or whatever contaminants are in SPAM or white bread?” evocomp asked. This led us to discover that the Pima in fact had been exposed to abnormal levels of lithium very early on, about 50x the median American exposure in the early 1970s. Before this, lithium had been just one hypothesis among many, but evocamp’s challenge and the resulting discoveries promoted it to the point where we now think it is the best explanation for the obesity epidemic. Good thing the community is helping us debug!

My original formulation was that every problem “will be transparent to somebody”. Linus demurred that the person who understands and fixes the problem is not necessarily or even usually the person who first characterizes it. “Somebody finds the problem,” he says, “and somebody else understands it. And I’ll go on record as saying that finding it is the bigger challenge.”

This is a classic in the history of science. One person notices something weird; then, 100 years later, someone else figures out what is going on. 

Brownian motion was first described by the botanist Robert Brown in 1827. He was looking at a bit of pollen in water and was startled to see it jumping all over the place, but he couldn’t figure out why it would do that. This bug sat unsolved for almost eighty years, until Einstein came up with a statistical explanation in 1905, in one of his four Annus Mirabilis papers. Bits of pollen jumping around in a glass of water doesn’t sound very interesting or mysterious, but this was a big deal because Einstein showed that Brownian motion is consistent with what would happen if the pollen was being bombarded from all sides by tiny water molecules. This was strong evidence for the idea that all matter is made up of tiny indivisible particles, which was not yet well-established in 1905!

Or consider DNA. DNA was first isolated from pus and salmon sperm by the Swiss biologist Friedrich Miescher in 1869, but it took until the 1950s before people figured out DNA’s structure. 

Complex multi-symptom errors also tend to have multiple trace paths from surface symptoms back to the actual bug. … each developer and tester samples a semi-random set of the program’s state space when looking for the etiology of a symptom. The more subtle and complex the bug, the less likely that skill will be able to guarantee the relevance of that sample.

For simple and easily reproducible bugs, then, the accent will be on the “semi” rather than the “random”; debugging skill and intimacy with the code and its architecture will matter a lot. But for complex bugs, the accent will be on the “random”. Under these circumstances many people running traces will be much more effective than a few people running traces sequentially—even if the few have a much higher average skill level.

This is making an important point: if you want to catch a lot of bugs, a bunch of experts isn’t enough — you want as many people as possible. You do want experts, but you gain an additional level of scrutiny from having the whole fuckin’ world look at it.

Simple bugs can be caught by experts. But complex or subtle bugs are more insane. For those bugs, the number of people looking at the problem is much more important than the average skill of the readers. This is a strong particular argument for putting things on the internet and making them super enjoyable and accessible, rather than putting them in places where only experts will see them.

Not that we need any more reasons, but this is also a strong argument for publishing your research on blogs and vlogs instead of in stuffy formal journals. If you notice something weird that you can’t figure out, you should get it in front of the scientifically-inclined public as soon as possible, because one of them has the best chance of spotting whatever you have missed. Back in the day, the fastest way to get an idea in front of the scientifically-inclined public was to send a manuscript to the closest guy with a printing press, who would put it in the next journal. (Or if possible, go to a conference and give a talk about it.)

But journals today only want complete packages. If you write to them about the tiny animals you found in your spit, they aren’t going to want to publish that. Times have changed. Now the fastest way to get out your findings is to use a blog, newsletter, twitter, etc.

Job Posting: Reddit Research Czar

Job postings are a kinda weird phenomenon. For one thing, they’re very modern. It used to be that most people either inherited a job (I’m a baker because my pa was a baker and our tiny hamlet needs a baker) or noticed an opportunity and ran with it (lots of hungry travelers cross that bridge every day, I bet I could make a living selling pancakes).

We’re talking about the second thing today, the opportunity just waiting for someone to snap it up. This is a job posting, but we’re not hiring. Reddit is hiring. Well, not REDDIT. The abstract spirit of reddit is hiring. The universe is hiring. 

hmmm yes

Let us try to explain.

Czar was originally a term for East and South Slavic monarchs, most notably the Russian emperor — it’s another spelling of Tsar and yet another corruption of the Roman title Caesar, just like Kaiser. But at some point in the middle of the 20th century it became a term in the US and UK for government officials “granted broad power to address a particular issue”. The Industry Czar is in charge of industry, the Milk Czar is in charge of milk, the Asian Carp Czar is in charge of Asian Carp (no, really), and so on and so forth.

Carp Czar Gone Wild

There are lots of problems in the world; some are covered, but there are many others where existing institutions have totally dropped the ball. Often, more research would help. But the academy just doesn’t move as fast as it used to. If you’ve ever looked at something and been like, “someone should do a study”, you know what we mean.

Reddit is a bizarre, amazing place. Literally millions of people have come together to this place on the internet and self-sorted into about 3.4 million communities, called subreddits. True, many subreddits are dedicated to very niche porn or insane crypto schemes. But if you want to build a desktop gaming rig, get male or female fashion advice, or discover long, plush horrors, there’s a subreddit for that. You can learn so much about any topic or hobby, maybe too much if you’re not careful (compare). 

We’d like to apologize to the ghost of Alan Turing

This means there are lots of special populations on reddit, people who have a condition or illness, maybe a rare one, who are extreme outliers (e.g. very tall and/or live in a submarine), or who have a burning obsession with some niche idea. Subreddits bring people together, to commiserate, to try to help each other solve a problem, or to post insane fanart.

These people are all very interested in their shared topic. They are all highly motivated. Many of them are ready to self-experiment, or are already self-experimenting. A lot of things count as self-experimentation. If you’re doing a diet, or trying to get more sunlight, or even just trying to drink more water, that’s self-experimentation too. So a subreddit for a given problem or topic is a powder keg of interest and motivation, just waiting for a spark. 

Because while subreddits are very motivated, they’re largely untapped for organized research. Even in subreddits with good leadership, it’s rare for the leadership to have a research background. Most communities lack someone with the methods skills to design a good study, and the statistical analysis skills to examine the data afterwards. 

If you have these skills, and you are familiar with reddit, you could show up and start helping people organize research. You could collaborate with people to help them solve their problems, or at least learn more about their problems, and you could start doing it tomorrow. 

Redditors could never be coordinated enough to pull off something as complex as scientific research!

Crowdsourcing research like this is under-explored. Almost no one has ever done studies organized like this, so in our opinion, there’s virtually guaranteed to be low-hanging fruit all over the place. Anything that isn’t sexy enough for a major journal or doesn’t sound serious enough for the NIH to spend their time on is ripe for the picking.

The current research world is very narrow-minded. Doctors and researchers are quick to blame a person’s behavior or hygiene and very slow to blame environmental contaminants. If you’re more creative or more open-minded, and you’re willing to consider other paradigms, you can just move faster. If doctors don’t take the pathogen paradigm for chronic disease and digestive disorders seriously, then by becoming the “Pathogenic Disease Czar”, you might be able to rack up discoveries really quickly.

There’s also the question of “why now”? Part of it is that the research world has slowed down. But another part is that the rest of the world has sped up. We’re more coordinated than ever. Today you can get 100 people reading your latest newsletter in 20 minutes. Today you can pop by a subreddit and consult with thousands of people in a matter of hours. Today you can cold-email an emeritus professor who worked on the problem in the 1970s and be on a Zoom call with them next week. 

Research tools are also opening up, getting more accessible every day. If you’re leading the reddit charge on some rare glandular disorder, it now takes only a couple hundred dollars per person for everyone involved to get their genome sequenced and it’s getting cheaper all the time. If there’s a genetic explanation, or genetics is involved in some way, it’s only recently gotten cheap enough that communities might able to find it on their own.

There are lots of interesting ideas where the only support for them is a single paper with 20 participants from 1994. If you can get a couple dozen volunteers together, boom, you’ve just advanced the state of the field, and discovered whether or not there was anything to that interesting idea.

One example is our own ongoing all-potato diet study, which we see as the first of what will hopefully be a long tradition of community trials and community RCTs (randomized controlled trials). We’ve mostly recruited from twitter for the potato diet, but we just as easily could have recruited from reddit. For reference, this was the response on one subreddit, and not even a subreddit directly related to dieting.

Sometimes just planting a flag in the sand is enough. People like to feel like a part of something and are excited to participate. One participant in the potato diet said:

How do we get stronger evidence [for the potato diet]? Well someone has to go out on a limb and run an experiment. This is a particularly important motivation for me. If this were not part of a larger study, I wouldn’t spend my energy on it (after all, it probably won’t work). But the fact that it might yield useful data makes it much more appealing.

Obesity and related issues (heart disease, diabetes, etc.) is just one example of a serious problem that people are invested in solving. It seems like there are lots of problems where we might be able to quickly learn a lot by rigorous self-experimentation and community research. 

Depression and anxiety are classic unsolved problems. Sure, we have some mildly effective treatments, but why don’t we have great ones? Why does a given treatment work for some people and not others? What about people with treatment-resistant depression? Why are things like exhaustion and brain fog symptoms of depression? Where does depression come from? There’s been a lot of discussion but our take is still “no one knows” or at least, “the jury’s still out”. We see that r/depression/ has over 800,000 members and a couple thousand are usually online at a given time. If you think you could help, they seem like they would be glad to have it. 

Crohn’s disease is debilitating and remains very poorly understood — Wikipedia, for example, says, “While the precise causes of Crohn’s disease (CD) are unknown, it is believed to be caused by a combination of environmental, immune, and bacterial factors in genetically susceptible individuals. …  While Crohn’s is an immune-related disease, it does not appear to be an autoimmune disease (in that the immune system is not being triggered by the body itself). The exact underlying immune problem is not clear; however, it may be an immunodeficiency state.” Sounds like more research is needed, and r/CrohnsDisease/ has 42,000 members.

If that’s not mysterious enough for your taste, there are all the really inexplicable digestive conditions, which go by names like IBS (irritable bowel syndrome) and GERD (gastroesophageal reflux disease). These can really fuck you up, so people will be really motivated to try things and find a treatment. And there might be weird treatments out there that really work. You can drop by r/ibs/ with 74,000 members or r/GERD/ with 42,000 members and start putting out surveys, today if you want! (But talk to the mods first, don’t get kicked out for being a weirdo.)

But you won’t be the first researcher on the scene. We see that u/OrganicSquare made a post titled “Let’s use machine learning to help us find solutions to our reflux. I need this whole community to answer this survey for data!!!” on r/GERD about a year ago. We can’t find the results — maybe she’s still analyzing the data — but this is exactly the sort of thing we’re talking about. OrganicSquare, you are the hero reddit needs, let us know if you want to collaborate.

There are also some populations that will be interesting not because they are facing a problem they want to solve, but because they are special in some other way. Trans people would love to have better resources for transitioning, and you could certainly drop by to help them study that. But we think the real reason to drop by r/TransDIY/ and similar subreddits is because you have literally thousands of people conducting n = 1 endocrinology experiments.

There’s a good chance the next great endocrinologist will be trans, just because of their personal familiarity with the subject and ability to self-experiment. If you want to see what effect testosterone/estrogen/progesterone/estradiol has on mood/energy/digestion/attention/nerve growth/body temperature/whatever, this is one of your few and best chances to get experimental data. 

This is nowhere near a complete list. In fact, please drop other subreddits that might be excited to do more community research in the comments.

It’s more common than you might think

We call this a job posting because we think this could easily be a full-time job. If you help a community or two get closer to solving their problem, even if you just help them coordinate and give them HOPE that their problem is solvable, it would be pretty easy to convince lots of them to chip in. It’s hard for an individual to hire an expert, but some of these communities have tens or hundreds of thousands of members. For a community that size, hiring some full-time research muscle is easy.

You set up a Patreon or a newsletter (we recommend Ghost), and ask for support. If you can get 1000 people to give you $3 a month, that’s $36,000 a year, enough to start thinking about doing this full-time.

You don’t need to solve anything up front. You just need to convince 1000 people that you’re doing enough to justify them spending $3 a month on something they think is important, which is not a hard sell. And if you get 10,000 people on board for $1, you’re even better off. (Incidentally, here is our patreon.)

Crowdfunding is the best and noblest option, but it’s not the only route you can take. Some communities will have a millionaire or two in the ranks, and if you start doing good work, people will come out of the woodwork to help. There are lots of granting agencies out there looking for stunning projects to throw money at. Start coordinating reddit research for a few months, show that you’re serious, make a little progress, and it should be easy to make the case for some grants.

And actually, you might also be able to get funding from reddit, up to $50,000! Starting June 2022, reddit will start distributing one million dollars in community funding to different subreddits. If you can make the case to a subreddit that you can lead their community research for a year, they can apply for $40,000 to be your salary, and there’s a good chance they’ll get it. The article linked above says, “I can’t wait to see what wild project the r/WallStreetBets crew tries to get $50,000 to pull off.” Yeah holy shit.

Finally, if you are financially independent / have a good job that gives you lots of free time, then this is DEFINITELY a job suited for you. You already don’t have to worry about money; maybe you even have enough that you could pay for a statistician / the chemical analysis of samples / new air quality monitors / sundry other research expenses. You’re looking for something interesting to spend your time on, something that also makes the world a better place. If you have the skills and inclination, nothing could be a better fit!

It’s worth touching for a moment on the skills we think would be important. Any research on reddit would probably start with a lot of surveys, so someone with lots of experience with survey-based methods might have the advantage here. Possibly a sociologist or psychologist? But on the other hand, a lot of the problems reddit communities would be interested in solving are medical, so maybe someone with a medical background is the best person for the role. On the other other hand, a lot of the advantage here might be statistical, having the skill to work with big strange datasets, so maybe a data scientist.

Or form a cabal if you want:

Reddit Research Cabal

Anyways, if this is the job you want, and you think you have the skills to do it, there are two general ways to approach this…

Go Specific

If you are a person who is a member of one of these communities, who is inclined towards research and wants to rally people to solve the problem, going specific might be the approach for you.

There are a couple winning examples already, let’s take a look. These two don’t use reddit for the most part — they have communities elsewhere — but it’s not hard to imagine recreating some of their successes in a subreddit rather than on a blog or on twitter.

Scott Alexander is pretty much the research czar for rationalists, in his reader surveys (both back on SSC and now on ACX), and in some more specific work like the nootropics survey. Rationalists aren’t a community with a rare disease to cure, but they are united in their interest in specific topics, like AI, IQ, and birth order effects. And Scott, being a psychiatrist, has a special interest in things like SSRIs. We’re very interested in the small amount of work he’s done on air quality / ventilation, which we’ll note has included at least a little self-experimentation.

Whorelord and “mad social scientist” Aella is kind of de facto sex worker / sex research czar for the whole internet. She also does psychology and psychedelics research, which must be reasonably well-regarded because her twitter followers include some big names in psychology, like Paul Bloom and Uri Simonsohn (and see this interaction). But mostly it’s sex stuff, and the quality of her research puts the average social science publication to shame: 

Scott is a rationalist and Aella has lots of sex / is a (former) sex worker, so they’re perfectly positioned to be the research czars for their communities. We’d recommend that the “go narrow” approach be taken with communities you are a part of as well.

There are clear advantages to going narrow. First off, you can self-experiment. You can pilot-test studies on yourself, and you can show people that you would never ask them to do anything you aren’t willing to try first. You can specialize and learn a lot about this one area of research. And you’ll understand the topic better, because you’ve lived it.

There are also a couple of disadvantages. This has a smaller scope, but some of you might like that. It’s less exciting, and maybe harder to get support and raise money for projects. But it’s also more practical.

Go Broad

The other option is to try to become the Czar of all the Reddits.

In this approach, you try to work with lots of different subreddits, lots of different communities, and try to solve lots of different problems. Instead of focusing on just one mystery at a time, you go broad. 

If you are a generalist with good research chops, who spends a lot of time on reddit and knows how it works, who likes the idea of working with tons of different people, on dozens of projects, this might be the approach for you.

This approach has some clear advantages. If you work on more projects, you will be able to get funding from more quarters. As you try more and more things, you’ll learn a lot about the metascience of doing this new kind of community research. You can switch between projects when you’re waiting for results. If you hit a dead end on one question, you can take some time off and switch to something else. More things to work on means it’s more likely something will be a success.

There are also a few disadvantages. You’ll always risk getting spread too thin, and you will spend lots of time getting familiar with new topics, instead of going deep on just a few. You probably won’t share most of the problems you want to help solve. Since you don’t have these diseases/conditions/whatevers, you won’t be able to self-experiment, and self-experimentation is an important part of research. And some communities won’t want or appreciate help from an outsider.

To Sum Up

Reddit is a big place. There’s a lot of questions to answer, problems to solve, and communities to rally to the mad science crusade. 

Probably by 2030 there will be several major researchers on reddit, and two or three of them will be getting close to being household names. Some of them will be generalists who hop around different subreddits, consulting on different problems. Some of them will be specialists, organizing their communities against shared problems. Different research czars will work together to make bigger and better projects, and problems will get solved faster than anyone today thinks possible. 

But why wait to see other people do it? If you think you have what it takes (or half of what it takes; don’t be afraid to learn on the job), there’s nothing stopping you from doing this starting tomorrow. We’d be happy to consult on stats and methods — and if you do anything interesting, we might blog about it. If you declare yourself Czar of X and you make a big breakthrough, we will send you a crown (though it will not be this nice).

Potato Diet Community Trial: Sign up Now, lol

In French, the word for potato is pomme de terre. This literally translates to apple of the earth. By this logic, potatoes are the lowest-hanging fruit of all.

More seriously: We keep getting more and more interested in the all-potato diet. This is a diet where you eat nothing but potatoes (and sometimes a bit of seasoning) for a few weeks to a few months. It sounds like a dumb gimmick that could never work, but there are a surprising number of people out there saying that they tried it, it worked for them, and they kept the weight off for months or even years after.

Anecdotes are limited in all sorts of ways, but there are a surprising number of very strong anecdotes about the all-potato diet causing huge amounts of easy, sustainable weight loss:

Again, anecdotes by themselves are limited. We don’t know how many people tried this diet and didn’t get such stunning weight loss. We don’t know how long the weight stays off for. And the sample size is really small. Someone should really do a study or something, and figure this thing out.

Well, ok, if you insist. But you all have to help! 

Tl;dr, we’re looking for people to volunteer to eat nothing but potatoes (and a small amount of oil & seasoning) for at least four weeks, and to share their data so we can do an analysis. You can sign up below.

Aren’t there already diets that work? Well, maybe, but we certainly don’t have any that work reliably. Reviews of meta-analyses say things like, “Numerous randomized trials comparing diets differing in macronutrient compositions (eg, low-carbohydrate, low-fat, Mediterranean) have demonstrated differences in weight loss and metabolic risk factors that are small (ie, a mean difference of <1 kg) and inconsistent.” And The Lancet says, “unlike other major causes of preventable death and disability, such as tobacco use, injuries, and infectious diseases, there are no exemplar populations in which the obesity epidemic has been reversed by public health measures.” We could go on like this all day — actually wait, we already did

There are all sorts of crazy fad diets out there that haven’t been formally tested, and many of them have anecdotes that sound at least this good. Some of you may have even tried one. So why are we so interested in this over all the others?

Most diets are unpleasant and require you to use a lot of willpower to eat the right stuff or avoid the wrong stuff. On most diets, people are hungry all the time and feel terrible and gain the weight back as soon as they stop dieting. But the potato diet, at least according to the anecdotes, isn’t unpleasant at all — it’s quite easy. This isn’t a willpower diet. If the diet works, and it’s as easy to stick to as they say, that would be an important finding.

Most diets are hard to follow in that the instructions are precise and/or complicated — you have to eat exactly the right ratio of stuff to other stuff, carefully weigh and measure all your portions, count calories, do a lot of math in your head, check all the ingredients in everything you buy, etc. In contrast, the all-potato diet is really simple. No complex principles. No weighing and measuring your food. No checking ingredients. Just potato.

Some diets claim they won’t work unless you do everything just right. If you don’t lose weight on one of these diets, fans of the diet can always fall back on saying, maybe you did it wrong. In comparison, potato diet is easy. We don’t think it really matters if you accidentally eat a chocolate bar, as long as you are eating mostly potatoes. If you eat mostly potatoes and you don’t lose weight, then the diet doesn’t work, no one will be saying “you did it wrong.”

The potato diet also appears to have a huge effect size — 20 lbs for Chris Voigt, 114 lbs for Andrew Taylor, etc. — which should make it easy to study. We’re not fiddling around with a diet that might make you lose 5 lbs. If most people lose as much weight as Chris and Andrew, that will be really obvious. And if it doesn’t work for most people, well, that’s an important finding too.

Finally, one of the most interesting things about the potato diet is that people seem to keep the weight off afterwards, which is basically unheard of for diets. If we can confirm that in a study, it will be a pretty big deal. 

So that’s why we want to study the potato diet in particular. It should be easy to get a straight answer about this diet. If it works, people will be able to use this diet to lose weight and gain energy, if that’s what they want. And if it works, it probably provides some kind of hint about why the obesity epidemic is happening in the first place. So let’s do a study.

Diet Design

To figure out how to run this study, we needed to figure out what kind of all-potato diet seems to work for weight loss. To do this, we took a close look at the case studies we mentioned above. Some of these accounts are pretty detailed, so we won’t bore you with it up front. If you want more detail, we give an overview of each case study in the appendices.

The overall picture looks pretty clear. The basis of the all-potato diet is, unsurprisingly, eating almost nothing but potatoes.

In the most extreme cases, like Penn Jillette and the Krocks, people appear to eat literally nothing but potatoes, with no seasonings, and drink nothing but water. This seems to work pretty well but sounds like it would be hard to stick to. It’s notable that both of these examples kept it up for only two weeks, though they did lose impressive amounts of weight.

In comparison, Andrew Taylor was able to stick to an all-potato diet for a full year. He let himself use spices and seasonings, drank things other than water, and he still lost more than 100 pounds. He just made sure to take a B12 vitamin and kept away from oil and dairy.

Chris Voigt lost the least weight, but he seems to have had a pretty easy time of it. He was able to lose 21 lbs while using all kinds of salt and seasonings and cooking his potatoes in oil, and he wasn’t even trying to lose weight at all. This suggests, to us at least, that stricter versions of the diet aren’t necessary to see the benefits.

Potatoes are indeed very nutritious (here’s the USDA page for russet potatoes). The official word is that they don’t contain any vitamin A and don’t contain any B12. We’re not sure about the vitamin A — Andrew Taylor went a year without supplementing vitamin A (he did take B12), but maybe he got all the vitamin A he needed from the sauces he used? In any case, a vitamin B12 supplement is appropriate, and a vitamin A supplement seems like a good idea. [EDIT: u/alraban on reddit points out that Andrew ate sweet potatoes, which are high in Vitamin A. This is a good point, so now our recommendation is that you should either include sweet potatoes or take a Vitamin A supplement.] If you take a normal multivitamin you should be totally covered — but again, none of the case studies seem to have needed it.

Based on these examples taken together, our version of the diet is: 

THE POTATO DIET

  • Drink mostly water. You can also have some other beverages. Chris Voigt had coffee, tea, and diet soda. Andrew Taylor sometimes had beer, even. Just don’t take them with cream or sugar and try not to get too many of your daily calories from your drinks. 
  • Eat potatoes. Buy organic if you can, and eat the peels whenever possible. Start with whole potatoes and cook them yourself when you can, but in a pinch you can eat potato chips or fries if you need to. You can calculate how many potatoes to eat (a potato is about 100 calories, so if you need 2000 kcal/day, eat about 20), but we think it’s better to eat the potatoes ad libitum — make a lot of potatoes and just eat as much as you want.
  • Perfect adherence isn’t necessary. If you can’t get potatoes, eat something else rather than go hungry, and pick up the potatoes again when you can. 
  • Seasonings are ok. Chris used seasonings like Tabasco sauce, chives fresh out of his garden, a Thai herb/pepper paste, and bouillon cubes in water for fake gravy. Andrew used seasonings like dried herbs, fat-free sweet chili, barbecue sauce, and soy milk (in mashed potatoes). Do what you can to keep yourself from getting bored.
  • Oil is ok. Chris used it, Andrew and Penn didn’t. You can go either way. In fact, it would be great for us if some of you use oil and others of you don’t, so we can see if there is any difference. If you do use oil, probably use olive oil, which seems to be what Chris used. Maybe consider imported olive oil from Europe, which we suspect contains fewer contaminants, in case the contamination theory is correct.
  • Take a daily B12 supplement, since potatoes don’t contain any. We like this version but use whatever you like. Take vitamin A if you’re not eating sweet potatoes. A multivitamin would also be fine as long as it contains B12. 
  • Everyone seems to agree: No dairy. Maybe this doesn’t matter, but on the off chance this is really important for some reason, please avoid all dairy products. 

If in doubt, pick one of the examples we describe in the appendices and follow their example. You can always ask yourself, what would Chris Voigt do? And then do that.

In the spirit of self-experimentation, and because we were curious, one of us decided to try the all-potato diet for ourselves. That author is currently on day 11 of the all-potato diet. In that author’s own words: 

I was originally going to do just one or two days of the potato diet to see what it was like, but it was so easy that I figured I should try to keep to it for a full week. But it was still easy at a week, and now I’m just curious how long I can keep going for.

I feel fine, totally normal. I don’t feel more energetic than normal, but I’m pretty energetic to begin with. My mood is a little better, and I’m maybe sleeping better. Exercise seems easier, or at least it’s not any harder, kind of surprising when all my protein comes from potatoes. I haven’t lost any weight but I’m not overweight so I didn’t have much to lose in the first place.

It doesn’t require any willpower. I don’t crave anything else, I’m not tempted to buy other food at the grocery store, I’m not jealous when people around me are eating pizza or chocolate. I’m happy to sit down to a pile of potatoes every meal. They still smell delicious. If anything, I like potatoes even more now. The hardest part is the logistics of preparing that many potatoes every single day. 

I’m using European olive oil, salt, spices, vinegar, and a couple of hot sauces to keep the potatoes interesting. I want to say that it would be much harder without them, but honestly, this is so much easier than I expected, I don’t know what to expect anymore. Maybe it would be just as easy without oil and hot sauce.

Here’s my advice based on my personal experience. You should get a wide variety of potatoes. When you’re eating nothing but potatoes, the differences between different varieties become very obvious. At first I was happy with yukon gold but after a few days I began to crave russet potatoes. Make a lot every time you cook, you will eat more than you expect. And make sure to drink lots of water, I keep finding it hard to remember and end up feeling dehydrated.

UPDATE DAY 13: For the last two days I tried nothing but baked potatoes with no oil and barely any spices. It was really easy, I feel super energetic, and I started losing weight. So if the diet isn’t having any effect for you, consider trying it with no oil.

Study Design

That’s the diet we’re thinking of. What about the study design? 

Official-sounding diet studies from like the NIH and stuff don’t always run all their subjects at the same time, so we won’t bother doing that either. We’ve made it so you can sign up and participate in this study at any time. Rolling admissions.

There’s no need for a control group because the spontaneous remission rate for obesity is so low. For example, if someone said they had invented a medicine that could re-grow lost limbs, we wouldn’t need a control group for that trial, because the spontaneous limb regrowth rate is almost exactly zero (in humans anyways). If anyone regrew their arms or legs, that would be pretty convincing evidence that the medicine works as promised. Similarly, people almost never spontaneously drop 20 pounds, so we don’t need a control group.

This is also a trap. We expect that some people will come back with “but there wasn’t a control group!” This is a sign that they didn’t actually read what we’ve written and are boneheads who don’t understand how research works.

We’re not worried about tight experimental control. Maybe this diet would work better in the lab, but what we are actually interested in is how it works when implemented by normal people in the comfort of their home. If it doesn’t work in those circumstances, we want to know that! If the potato diet can’t be used practically, we don’t really care if it works in the lab, we know which side our potato is buttered sprinkled with garlic salt on. If it doesn’t work with this design, it just doesn’t work. And if it does work at home, it would presumably work even better in the lab. 

We’re also interested in the huge effect size described in the anecdotes above. We’re not worried about tiny amounts of noise from things like what you’re wearing or what time of day you weigh yourself. If the experience of Chris Voigt is at all typical — if the average person loses about 20 lbs — these tiny differences won’t matter.

And we’re not all that worried about adherence. If the 100% potato diet works, the 90% potato diet probably works too. So while we prefer that anyone sending us their data tries to refrain from eating any delicious pickles during the diet, if you do eat a pickle, it probably doesn’t matter.

Sign up to Eat Potatoes for the Glory of Science

This looks pretty promising, so let’s try to go past the anecdotes and do this in something like a rigorous fashion. Who wants to eat some ‘taters? 

The only prerequisite for signing up is being willing to eat nothing but potatoes for at least four weeks, and being willing to share your weight data with us.

(And being an adult, having a scale, not being allergic to potatoes, etc. etc.)

One reason to sign up is that you hope this will help you lose weight, lower your blood pressure, make you less depressed, or see one of the other effects reported by people like Chris Voigt and Andrew Taylor. But another reason you might want to sign up is to help advance the state of nutritional science. In a small way, this study will tell us something about nutrition, weight loss, and obesity that we don’t currently know. If the diet works, it will give us a practical intervention that people can use to reduce their weight, which we don’t really have right now.

And beyond that, running a study like this through volunteers on the internet is a small step towards making science faster, smarter, and more democratic. Imagine a future where every time we’re like, “why is no one doing this?”, every time we’re like, “dietary scientists, what the hell?”, we get together and WE do it, and we get an answer. And if we get a half-answer, we iterate on the design and get closer and closer every time. 

That seems like a future worth dreaming of. If you sign up, you get us closer to that future. We hope that this is only the first of what will be a century full of community-run scientific trials on the internet. Maybe by 2030, the redditors will have found a way to triple your lifespan. But for the first study, let’s start with potato.

We understand that eating nothing but potatoes for four weeks sounds pretty daunting. But based on the case studies above, and our own experience, we want to reassure you that it will probably be much easier than you expect. In fact, here’s our suggestion: If you are at all interested in trying it, go ahead and sign up and start collecting your data. Try the first day or two and see how it feels.

If it’s really hard for you to stay on the diet and you just can’t continue, go ahead and stop, just send us an email and close out the diet as normal (see instructions below). We’re interested in the diet as a whole, and if 40% of people can’t stick to the diet for more than two days, that’s important information about how effective the diet is in a practical sense. We’d be happy to have that information. 

But based on our own experience, we suspect that most of you who try it for a couple days will be like, “wow this is so easy! I could do this for a couple weeks no problem.” If that’s how you feel, keep collecting your data and see if you can keep it up for four weeks. 

If you want to go for longer than four weeks, that’s great, we would be happy to have more data.

If at any point you get sick or begin having side-effects, stop the diet immediately. We can still use your data up to that point, and we don’t want anything to happen to you.

If you are taking potassium supplements, often given as blood pressure medications (like Losartan) please take this extra seriously. A diet of 20 potatoes a day will give you about 300% your recommended potassium. While this should be safe by itself, it might be a problem if you are already taking a potassium supplement. Don’t sign up if you have bad kidneys, kidney disease, or diabetes (you can check with your doctor). Be aware of the signs of hyperkalemia.

We are mostly interested in weight loss effects for people who are overweight (BMI 25+) or obese (BMI 30+), but the energy and mental health effects reported in some of the case studies are interesting too. If you are “normal weight” (BMI 20-25) you can also sign up, especially if you want to feel more energetic or you want to tackle depression and anxiety or something. 

And for everyone, please consult with your doctor before trying this or any other weight loss regimen. We are not doctors. We are 20 rats in a trenchcoat. eee! eee! eee!

Anyways, to sign up: 

  1. Fill out this google form, where you give us your basic demographics and contact info. You will assign yourself a subject number, which will keep your data anonymous in the future. [UPDATE: Signups are now closed, but we plan to do more potato diet studies in the future. If you’re interested in participating in a future potato diet study, you can give us your email at this link and we’ll let you know when we run the next study.]
  2. We will clone a version of this google sheet and share the clone with you. This will be your personal spreadsheet for recording your data over the course of the diet.
  3. On the first day, weigh yourself in the morning. If you’re a “morning pooper”, measure yourself “after your first void”; if not, don’t worry about it. We don’t care if you wear pajamas or what, just keep it consistent. Note down your weight and the other measures (mood, energy, etc.) on the google sheet. Then spend day 1 eating nothing but potatoes. On day 2, weigh yourself in the morning, note down data in the sheet, then spend day 2 eating nothing but potatoes. On day 3, etc.
  4. We prefer that you stick closely to the diet for at least four weeks. But if you do break the diet at some point, just note that down in the appropriate column and try to stick to the diet the next day. Again, we’re interested in how the diet works for normal people at home, and so imperfect adherence is ok. If you totally can’t stand the diet, just stop doing it and end the study per the next instructions.
  5. Whenever you are done with the diet (preferably four weeks, or longer if you want, we’re happy to have more data if you are enjoying the diet), weigh yourself and fill out one last morning’s data so we have an endpoint, then stop the diet.
  6. Then, send us an email with the subject line “[SUBJECT ID] Potato Diet Complete”. This will let us know to go grab your data. This is also your opportunity to tell us all about how the diet went for you. Please tell us all the data that doesn’t easily fit into the spreadsheet — how you felt on the diet, what brand of oil you used, what kind of potatoes you bought, where you got them from, what kind of cookware you used, before and after pictures (if you want), advice to other people trying the diet, etc. We think there’s a pretty good chance that this diet will work for some people and not for others, and if that happens, we will dig into these accounts to see if we can figure out why (e.g. maybe this works with olive oil but not with vegetable oil, or something).
  7. If we have our act together, we will send each of you a brief google form following up at 6 months and at 1 year, and maybe at future intervals (5 years?).

Assuming we get 20 or so people, we will write up our results and publish them on the blog. We would really like to get a couple hundred people, though, since at that point it becomes possible to do more complex statistical analyses. So if you think this is an interesting idea, please tell your friends. 

We’ll keep this updated with roughly how many people have signed up and stuff, until we get bored or decide the study is closed:

Signed Up: 220 [CLOSED]

Past the 4-Week Mark: 46

We’re pretty happy with this study design. In particular, we don’t think it’s a weakness that people are doing this at home, since those are the conditions that we actually want to understand the diet under. We want to know how it works when it’s applied like it would actually be applied.

That said, if you are a wealthy donor and you want to fund a more controlled version of this — maybe, send 30 overweight and obese volunteers to a campground in Colorado for a couple weeks and feed them nothing but potatoes while they’re there, and hire a nurse or two to check up on them every day — please contact us. It’d be cheap as far as nutrition research goes, and we’ll make you a mixtape of potato songs.

Appendix A: Super Basic Potato Preparation

Use whatever recipes you want, but here are two very simple ways to prepare them.

Here’s how to roast any kind of potato:

  1. Preheat oven to 425 F.
  2. Spread a thin layer of olive oil on a large cookie sheet.
  3. Wash potatoes and make sure they do not have any dirt or anything gross on them.
  4. Cut off any gross spots on the outside of the potatoes.
  5. Cut the potatoes into any of the following: large fries, slices about a quarter inch thick, or chunks a little bigger than a grape. Do the whole batch with the same method.
  6. If you find any other bad spots while you’re cutting up the potatoes, cut them off and throw them away.
  7. Put the cut potatoes in a large bowl and dress them with olive oil, salt, and whatever seasonings you want (salt, pepper, garlic powder, rosemary, etc.). Mix them so the oil and seasoning is all over the potatoes.
  8. Put the potatoes on the cookie sheet and make sure they are all well seasoned / well oiled.
  9. Put them in the oven for 20 minutes, then take them out and stir them with a wooden spoon or spatula. They will probably stick to the cookie sheet a bit, this is normal.
  10. Put them back in for another 20 minutes and then take them out again. Let one cool and try it, making sure not to burn your mouth. If it seems done and edible, turn off the oven, your potatoes are done. If it still seems a little raw, put them back in for another 10 minutes.
  11. When done, eat with your favorite no-calorie sauces and vinegars.

Here’s how to boil any kind of potato:

  1. Fill a pot with enough water to cover however many potatoes you’re making. Salt the water and set it on the stove on high to boil.
  2. Wash potatoes and make sure they do not have any dirt or anything gross on them.
  3. Cut off any gross spots on the outside of the potatoes.
  4. Cut the potatoes into small chunks. Any size is fine, but smaller chunks will cook faster.
  5. If you find any other bad spots while you’re cutting up the potatoes, cut them off and throw them away.
  6. When the water boils, put the potatoes in and turn the heat to medium.
  7. Every five minutes, pull out a potato chunk, let it cool, and taste it to see if it’s ready. 
  8. When they are done, turn off the heat and pour the potatoes out into a colander. 
  9. Dress the potatoes with spices and olive oil (you probably want to add salt) and eat with your favorite no-calorie sauces and vinegars.

Appendix B: Chris Voigt

The earliest example of an all-potato diet we’re aware of is a guy named Chris Voigt

Chris was the Executive Director of the Washington State Potatoes Commission, and he was tired of hearing all the myths about potatoes being unhealthy. He wanted to remind people about the amazing nutrients contained in this everyday vegetable. So as a demonstration of the power of potato, he decided to eat nothing but 20 potatoes a day, for 60 days straight:

Chris started his diet on October 1, 2010, and didn’t use any milk, butter or cheese toppings for mashing his potatoes. The only way he had them were fried, boiled, mashed, steamed, chipped or baked. His diet continued for 60 straight days and ended on November 29, 2010.

Also here’s an incredibly corny video if you prefer that format.

Chris wasn’t trying to lose weight. In an interview conducted years later, he said, “I was kind of hoping to be alive at the end of the 60 days… I wasn’t trying to lose weight.” He was 197 pounds at the start of his diet and he describes himself as “six foot one and a half”, so his starting BMI was about 26, just slightly overweight. He seems to have been eating a pretty healthy diet beforehand and he wasn’t seriously overweight, which is why he didn’t think he would lose weight. In fact, he based his daily potato consumption off of a calculation of how much he would need to eat to maintain his starting weight. In response to an early comment on his blog, he said, “I’m eating 20 potatoes a day because that’s how many I’ll have to eat to maintain my current weight.”

But despite his best efforts, by the end of the 60 days, he weighed 176 lbs, a loss of 21 lbs to a BMI of 23.2. His cholesterol also went from 214 to 147, and his glucose went from 104 to 94. In fact, seems like almost everything that could be measured improved: “My cholesterol went down 67 points, my blood sugar came down and all the other blood chemistry — the iron, the calcium, the protein — all of those either stayed the same or got better.” (Here’s a page where someone has compiled a bunch of these numbers.)

Chris did all this in consultation with his doctor, and he does suggest that you have to have a baseline level of health for this to be safe: 

Chris Voigt didn’t go on 20 potatoes and a diet blindly. He first carried out thorough consultations with his dietician and doctor to be sure that he could actually live on potatoes for 60 days straight. After all, you need hale and hearty kidneys for processing the excessive potassium provided by 20 potatoes every day. In addition, you should have also stored ample amounts of necessary nutrients that are lacking in potatoes, for instance vitamin A, for avoiding any harmful side effects.

Those were his results. What was the diet like? 

In the abstract, Chris describes his diet like this

Literally, I just ate potatoes and nothing else. There were a few seasonings, but no gravy, no butter, no sour cream, and just a little bit of oil for cooking. That was it.

That isn’t quite enough detail for our purposes. But older archives of Chris’s site have the blog, which gets a lot more specific. Read it for yourself for the full story, but here are some highlights, focusing on what kinds of potatoes he ate and how he prepared them:

Day 1 – So I had 5 baked red potatoes for breakfast, mashed potatoes with a little garlic seasoning for lunch, and while my family had all the fixing at the steakhouse celebrating my wife’s birthday, I had garlic mashed potatoes and an order of steak fries. The all potato diet wasn’t too bad today, but I did cringe a little when everyone had ice cream for dessert.

Day 2 –  I’m really struggling to eat enough calories. I had two baked potatoes this morning with a couple shots of Tabasco sauce, a serving of mashed potatoes sprinkled with a few BBQ potato chips for a change in texture, and another serving of mashed potatoes and 5 roasted small red potatoes. I didn’t hit the 2200 calories I was hoping for today. I didn’t realize how filling the potatoes would make me feel.

Day 4 – My wife made me 3 pounds of roasted red potatoes that were lightly coated in olive oil with some of her special seasonings. While I made two containers of russet mashed potatoes, one with chives fresh out of our garden and one with a Thai herb/pepper paste I’ve never had before. My wife tells me the paste goes a long way and be careful not to use too much.

Day 6 – I was in potato Nirvana tonight. My wife boiled a bouillon cube with potato starch to make me “psuedo gravy”. It was awesome! She smothered Yukon Gold and Purple potato slices in this gravy and baked it in the oven for an hour. Then cooked homemade yellow and purple chips with artifical sweetner and cinnamon for dessert. It was heaven for a flavor deprived husband. I would marry her all over again because of this!

Day 11 – So one thing people keep asking about is, “What about my weight?” I’ve been hesitant to talk about this because I don’t want people to think of this as a weight loss diet. It is not, and it’s not something I want people to replicate. … So let me step down from my nutrition soap box and talk about weight. I started this diet at 197 pounds. I’m six foot one and a half so according to my BMI, I was a little over weight. I should be in the 175-185 range. Right now, I’m at 189 pounds. Most of that weigh loss happened early, only because I was struggling to eat enough potatoes. I seemed full the whole time so it was hard to keep eating. But now, my weight loss has become more stable.

Day 15 – I feel good. Lot’s of energy, I’m dropping a few pounds which I needed to, and no weird side effects. And mentally, I think I’ve found my groove. Weekdays are pretty easy but weekends are a little tougher, still have desires for other foods but I think those a waning a bit as I get further into this diet.

Day 19 – So my family had potstickers last night while I had roasted red potatoes. For the potstickers, my wife made a dipping sauce that I tried on my red potato wedges. It was pretty good. The sauce was soy sauce, ginger, and some off the shelf dry asian seasoning. It was a nice change of pace. It added a flavor I haven’t had in a long time.

Day 22 – I had about a pound of hash browns this morning for breakfast, two pounds of mashed potatoes with black pepper for lunch, which means I have to eat close to 4 more pounds before bed. I’m leaning towards baked potatoes with balsamic vinegar for dinner but I’m not sure I’m ready for 4 pounds of it.

Day 24 – So here is a new one for you that my wife made up. Fake ice cream made from potatoes. She took 1/2 cup cocoa powder, 1/2 cup artificial sweetner, and a little water to make a chocolate sauce. Then mixed it with about 2 cups of “riced” potatoes and ice. Blended it and put in freezer. It was actually really good, ju…st a strange texture though. I love my wife! What a treat!

Day 26 – I brought my food for the day and stuffed it in the office fridge. Two pounds of purple mashed potatoes topped with garlic salt, 6 smalled baked red potatoes that I’ll probably put balsamic vinegar on, and about 10 oz of gnocchi made with riced potatoes and potato flour, then lightly fried. Can’t boil them because they fall apart since they don’t have the egg in them that you would normally use.

…  I drove to Spokane Sunday night and caught an early flight to Boise the next day. Must remember to prepare better! Nearly starved! I broke into a small emergency stash of instant potatoes I had with me for breakfast, had 3 small bags of …chips and 1 baked potato for lunch, and an order of fries at McD’s for dinner.

Day 28 – So here is what I had yesterday to eat. About 2 pounds of roasted red potatoes lightly seasoned and with a little olive oil, 3 pounds of purple mashed potatoes sprinkled with garlic salt, and about a pound and a half of “riced” potatoes that were fried up lightly. It was kind of like light fluffy hash browns. And a few handfuls of potato chips for a change in texture.

… think about how weird and unusual this diet is. Health professionals actually suggested I include some fries and chips prepared in healthy oils as part of my diet to make me more healthy during this diet. Doesn’t that sound so weird out loud or written in this blog? You have to remember that there is absolutely no fat in a potato, no fat in any of the seasonings or herbs I’m eating. But there are 2 fatty acids that are essential to bodily functions and are needed by your body. The healthy oils from the fries and chips are supplying me those fatty acids. Without them, I would not look or feel very good at the end of these 60 days. The take home message, you need those fatty acids to live but the reality for most people is that we eat too many of them. Live in moderation!

Day 33 – Got out of the house this morning without any seasonings for my spuds. So far, I’ve eaten 6 boiled, yellow flesh, plain potatoes. You know…I really think this is getting easier. I’m not having the intense cravings for other foods that I use to have. Maybe I’ve found my groove.

…  I thought I’d take a moment to answer a couple questions I always get from folks about the diet. One is, “Are you taking any supplements?” No. This diet is about nutrition, there are so many nutrients in potatoes that you could literally live off them for an extended period of time without any major impacts to your health. If I could take supplements, I think you could probably do this diet for a really long time! Also, I get asked about beverages. I drink mostly water, but can have things that don’t add calories or any major nutrients. I do drink some black coffee, plain black tea, or an occasional diet soda.

Day 45 – I just ate about a kilo of purple mashed potatoes for dinner tonight. But I think I added too much garlic salt. Probably shouldn’t do any major kissing tonight. 🙂

Day 50 – Just in case I’m subjected to a lie detector test at some point, I have to come clean on 3 incidents. There were 3 separate times in the previous 50 days where I was making my kids lunch, peanut butter and jelly sandwiches, and without thinking, it was more of a reflex move, I licked clean the peanut or jelly that had gotten on my fingers. Its been bugging me so I needed to share.

Day 60 – So here are most of the stats from my latest medical exam and how it compares to where I was prior to the start of the diet. Weight, started at 197, finished at 176. Cholesterol, started at borderline high of 214, finished at 147. Glucose, started at 104, dropped to 94. So improvements in each of those catagories. I don’t have a hard copy yet, will try to get that tomorrow and will post online. Me Happy!!

Day 61 – (Diet officially over) Its funny because I still have yet to eat something else besides potatoes. I’ve been a little busy this morning so I wasn’t able to pack a lunch or breakfast. But the fridge in our office still had a couple of my potato only dishes. So guess what I had for my first meal at the end of the diet. Potatoes! Hopefully that will change later today. And I bet there will still be potatoes tonight, but with something on them or with them!

… One more thing, a few new folks have joined our little community and have sent me questions about the diet. First, I took no other supplements. It literally was just potatoes, seasonings, and oil for cooking. Now there were a few things we did classify as seasonings since they didn’t really add any significant nutrients, such as Tabasco Sauce which is really just dried peppers and vinegar. Had balsalmic vinegar a few times, and an occasional bouillon cube that was used in mashed potatoes or mixed with potato starch to form something like gravy. THe cubes were 5 calories and really only added sodium to the diet, which we consider a seasoning. 

Day 63 – A big thank you to the Washington Beef, Dairy, and Apple producers. They, along with the Washington Potato Commission, hosted a dinner at the Moses Lake Head Start facility for all the kids and their parents. We did crafts and a short nutrition workshop on the importance of eating healthy, well balanced meals. Not just 20 potatoes a day 🙂 And a big thank you to the staff for all of their work on this and the wonderful Mr. Potato Head they gave me. We had lean beef strips for our tortillas, along with roasted onions, peppers, and potatoes, and apple slices and low fat milk. I sampled everything and wanted to chow down but my doctor has advised me to ease back slowly into other foods. So I’m still eating a lot of potatoes!

On the one hand, Chris took the potato diet very seriously. He really did get almost all his calories from potatoes for about 60 days. He stuck to the plan.

On the other hand, he didn’t take it too seriously. He used cooking oil, spices, and a bunch of different seasonings. He still had coffee, tea, and the “occasional diet soda”. But this didn’t ruin the diet — he still lost weight and gained energy.

The results do seem astounding. More energy, better sleep, lower cholesterol, etc. etc. And how was it subjectively? “I’m really struggling to eat enough calories. … I didn’t realize how filling the potatoes would make me feel. … I feel good.” 

The weight loss results aren’t that extreme, but Chris wasn’t very overweight to begin with. He went from a BMI of 26 to an “ideal” BMI of 23. He didn’t really have many more excess pounds to lose. So let’s take a look at a more extreme example. 

Appendix C: Andrew Taylor

Andrew Taylor is an Australian man who did an all-potato diet for a full year. He started at 334 pounds and he lost 117 pounds over the course of what he called his “Spud Fit Challenge.”

Here’s a video of Andrew before the diet, describing what he is about to attempt. Here’s a video of him 11 months in. And here are some descriptions of how it went

The physical benefits of Taylor’s Spud Fit Challenge remain, he says. “I’ve maintained the weight loss and I’m still free of the daily grind of battling with food addiction. I had a check up a few weeks ago and my doctor was very happy with the state of my health.”

Taylor says that he was clinically depressed and anxious before undertaking his all-potato diet, “which is no longer an issue for me,” he says. “My mental health is much better these days.”

During his challenge, Taylor ate all kinds of potatoes, including sweet potatoes. To add flavor to his meals, he used a sprinkle of dried herbs or fat-free sweet chili or barbecue sauce. If he made mashed potatoes, he only added oil-free soy milk.

He drank mostly water, with the occasional beer thrown in (proof that no man can resist a great brew). Because his diet completely lacked meat, he supplemented with a B12 vitamin.

He also didn’t restrict the amount he consumed. Instead, Taylor ate as many potatoes as he needed to satisfy his hunger. For the first month, he didn’t work out at all and still dropped 22 pounds, but then he added 90 minutes of exercise to his routine every day.

 “I feel amazing and incredible! I’m sleeping better, I no longer have joint pain from old football injuries, I’m full of energy, I have better mental clarity and focus,” he writes on his site.

Like Chris Voigt, Andrew made sure to get regular checkups

Taylor said has had medical supervision, including regular blood tests, throughout the year. His cholesterol has improved and his blood-sugar levels, blood pressure and other health indicators are good, he explained. He feels “totally amazing,” noting he no longer has problems with clinical depression and anxiety, sleeps better, feels more energetic and is physically stronger.

Andrew is now running spudfit.com. For the specifics of Andrew’s diet, the FAQ is pretty detailed: 

A combination of all kinds of potatoes, including sweet potatoes. I used minimal dried and fresh herbs, spices and fat-free sauces (such as sweet chilli, tomato sauce or barbecue sauce) for a bit of flavour. I also use some soy milk (no added oil) when I make mashed potatoes.

I drank only water and the occasional beer. I didn’t drink any tea or coffee but I’ve never liked them anyway. If you want to drink tea or coffee I think that would be fine as long as you use a low fat (no added oil) plant based milk.

For the first month I did no exercise and still lost 10kgs. After that I tried to do around 90 minutes of training every day. I DID NOT exercise for weight loss, I did it because for the first time in years I had excess energy to burn, enjoyed it and it made me feel good. I think that whatever the amount of exercise I did, my body adjusted my hunger levels to make sure I take in enough food. If I didn’t let myself go hungry then I was fine.

Rule 1: Do your own research and make educated decisions – don’t just do things because you saw some weird bloke on the internet doing it! Also get medical supervision to make sure everything is going well for you, especially if you are taking any medications.

Rule 2: Eat a combination of all kinds of potatoes, including sweet potatoes. I have minimal herbs, spices and fat-free sauces for a bit of flavour. I also use some soy (or other plant-based with no added oil) milk when I make mashed potatoes. Also take a B12 supplement if you plan on doing this for longer than a few months. Definitely no oil – of any kind – or anything fatty such as meats, cheeses, eggs or dairy products (even lean or low-fat versions).

Rule 3: DO NOT RESTRICT OR COUNT CALORIES. I eat as much as I like, as often as I like, I do not allow myself to go hungry if I can help it.

I used a non-stick granite pan and fry in water or salt reduced vegetable stock. When I used the oven I just put the potatoes straight on the tray. I also liked to cook potatoes in my pressure cooker and my air fryer.

I felt amazing and incredible and I still do! My sleep improved, joint pain from old football injuries went away, I gained energy and improved mental clarity and focus. Also I lost 52.3 kilograms (117 pounds) over the course of the year. By far the best part is that I no longer suffer with clinical depression and anxiety.

I tried to keep it as simple as possible. I didn’t own an air fryer or a pressure cooker or any other special gadgets. Most of what I ate was either boiled, baked or mashed potatoes. I would make a really big batch of one type and then eat it for a day or two until it was gone and then repeat.

(did you eat the skins?) I did but if you don’t want to that’s ok too.

This is the most surprising thing of all, I can’t explain why but I’m not at all bored of my potato meals.

Over the month of January, following the completion of my Spud Fit Challenge, I lost another 2kg (4lbs). This took my total weight loss to 55kg (121lbs) and meant I weighed the same as I did when I was 15 years old – 96kg (211lbs)! Since then I’ve stopped weighing myself so I can’t be sure of what I actually weigh, my new clothes still all fit though and I still feel good so I guess my weight is around the same (nearly 15 months later at the time of writing this).

This diet looks pretty similar to what Chris did. All potatoes but not wildly strict — he would have seasonings and sauces and even an occasional beer. The big difference is that Andrew studiously avoided added oils, and took a B12 supplement. 

The B12 seems like a good addition to us, especially since Andrew was doing this for a full year, because potatoes contain almost no B12. Hard to say if avoiding oil was important but using oil didn’t keep Chris Voigt from seeing a lot of benefits from potatoes. On the other hand, Andrew didn’t seem to miss it. 

Appendix D: Penn Jillette 

Penn Jillette, of the famous magician duo Penn & Teller, lost over 100 lbs, down from “probably over 340”, on a diet that started with a 2-week period of nothing but potatoes.

You can hear him describe his process in this video, but here are a few choice details: 

I didn’t mind not being energetic and stuff. But I started having blood pressure that was stupid high like, you know, like English voltage, like 220 even on blood pressure medicine.

If you take medical advice from a Las Vegas magician you are an idiot who deserves to die. You have to do this for yourself and with your proper medical professionals.

And one of the really good ways to do that that worked tremendously for me is what’s called the mono diet which is just what you think from the root, eating the exact same thing.

And I could have chosen anything. I could have chosen corn or beans or whatever. Not hot fudge but anything. And I chose potatoes because it’s a funny thing and a funny word.

For two weeks I ate potatoes, complete potatoes – skin and everything and nothing added, nothing subtracted. When I say nothing subtracted I mean no skin taken off but also no water. You can’t cut it up and make it chips in a microwave. Don’t take water out of it. 

Leave the potato completely – so that means baked or boiled and not at any mealtime. You don’t get up in the morning, eat a potato. You don’t eat it at lunch or dinner. Mealtimes are obliterated. When you really need to eat, eat a potato. And over that first two weeks I lost I believe 14 pounds. So already I’m a different person.

Then after that two weeks I went to, you know, bean stew and tomatoes and salads. But still no fruit and no nuts. Certainly no animal products. And I lost an average – these words are careful – an average of 0.9 pounds a day.  So I took off pretty much all the weight in three or four months, in a season, in a winter.

And that was 17 months ago. So I’ve kept the weight off for 17 months. Now two years is magic. Very few people keep it off for two years. I’ve got seven more months to go. I think I have a shot at it.

I feel better. I’m happier. I’m off most of my blood pressure meds. Not all of them, it takes a while for the vascular system to catch up with the weight loss. I have more fun. I believe I’m kinder.

All of that having been said now that I’m at target weight I also – this is important – I also didn’t exercise while I was losing the weight. Exercising is body building. It’s a different thing. Wait until you hit the target weight, then you exercise. Then it’s easy. Then it really does good. But while you’re losing weight make it winter. Sleep a little more. Get sluggish. Let your body just eat the fat that you’ve stored up just the way you should. Hibernate a little bit. Let it eat the fat. Be a little bit like a bear.

Again, a pretty impressive story. And, as of 2019, he seems to be keeping it off.  

Appendix E: Brian & Jessica Krock

Penn’s example inspired a similar attempt from the Krocks, a couple who have jointly lost over 220 lbs starting with two weeks of an all-potato diet

He was 35 when we started this journey and tipped the scales at 514 pounds. My own weight was approaching 300 pounds and my health was starting to suffer. High blood pressure, anxiety and acne were just the start of my issues. 

We picked a start date on the calendar (June 22, 2018 – which also happened to be the 11th anniversary of when we first started dating) and started doing research. The first book I read was Penn Jillette’s Presto!: How I Made Over 100 Pounds Disappear and Other Magical Tales. It was exactly what I needed to get into the right frame of mind for starting this journey. It wasn’t a book from a doctor or a nutritionist or someone telling me why eating the way I did was going to kill me. It was a book from someone who KNEW the real struggle we have dealt with for years. Someone who spend years overweight, LOVED food, and didn’t buy into the whole “eat in moderation” philosophy a lot of our past failed diets relied on.

The first day of potatoes sucked. I seriously contemplated quitting during the FIRST day. After eating my first round of potatoes, I literally walked from our apartment to a grocery store to look at the extra cheesy hot-and-ready pizza I thought I needed. I gazed at the pizza and walked around the store looking for something to eat. Luckily, I was able to keep it together and walk out of the store and back home to my pantry full of potatoes.

I’m not trying to be dramatic, but it was seriously one of the hardest things I’ve done in my life. It took more will power than I thought either of us had.

Even when we started the two weeks of potatoes, we still weren’t sure what the heck we were supposed to do after that. We knew it was vegan. We knew we wouldn’t be able to use added salt, sugar, oil, etc. But that was about it. So we did a lot of research during those two weeks of eating nothing but potatoes. From what I could tell, after the two weeks of potatoes, Penn Jillette followed a whole food, plant-based diet for the most part, so we decided to stick with that.

 We will never go back to eating the way we used to eat. As hokey as it might sound: This is not a diet – it is a lifestyle. We know if we go back to our old ways, we’ll gain the weight back again. The best part is… we don’t want to go back to how we ate before! We actually enjoy food more now than we did before. We have a better relationship with food. We feel like we eat MORE variety now. Eating a whole food, plant-based diet has opened our minds and palates to a new world of food that we would not have given a second thought to before.

They seem to have had a harder time than the other examples we looked at. But we also notice they are the heaviest people we’ve looked at so far, so it’s not hard to imagine that it might have been roughest for them. But even so, it seems to have worked. 

As far as we can tell, they are following Penn’s approach over what Chris and Andrew did — no oil or nothin’, just potatoes. Our sense is that this is probably more hardcore than what is necessary but like, more power to them. On the other hand, this may be part of what made it so difficult. Even Andrew used seasonings! Detailed instructions for how they prepare Taters appear in their videos.

The Krocks are still making videos, and if you look at their channel, they seem to have kept a lot of weight off.

Appendix F: Potato Hack

We are also going to talk about potato hack. This is not a case study per se but it is another all-potato approach, and one that has lots of very positive reviews on Amazon, for whatever that’s worth.

Per the website, “The Potato Hack (aka The Potato Diet) is an extremely effective method for losing weight without experiencing hunger.”

The Potato Hack Overview has this to say about the details: 

Red and yellow potatoes work the best, because after they are boiled they keep longer than Russet potatoes, which tend to get mushy quicker. However, Russet potatoes do work. Try all potato types.

Sweet potatoes are not potatoes. They can work for some people, but not nearly as well. If you can not handle nightshades, purple yams with white flesh can be a substitute. Weight loss is likely to be slower when you don’t use regular potatoes.

The only way to make the potato fattening is to process it and cook it in oil. So avoid fries and chips. For the potato hack to work the potatoes need to be cooked only in water. Boil, steam, or pressure cook.

When cooked potatoes are cooled overnight in the refrigerator they develop something called resistant starch. Resistant starch is beneficial to our gut flora, balances blood sugar, and other additional health benefits. These resistant starches are not digested in the same manner as regular calories, so they have the effect of reducing the calories of potatoes.

Refrigerating cooked potatoes overnight will reduce the calories by about 17%. The potatoes can be reheated before eating without losing any of the resistant starch.

The potato hack will still work if you don’t refrigerate the potatoes, so although this step is encouraged, it is optional.

Eat the potatoes plain. Salt if you must. You can add a splash of malt or red wine vinegar if a blood sugar spike is a concern, although cooling the potatoes will reduce the glycemic response.

To get the full benefit of the potato hack, it is strongly advised to eat the potatoes plain. You are teaching your brain how to get full without flavor. This is the opposite approach taken in dieting where one continues to get flavorful food but in a restrictive manner.

With the potato diet, do not walk away from the table hungry. Eat until full.

This is a little more finicky (what potatoes to use, how to store them, etc.) but overall looks a lot like the other examples we’ve considered. 

The hack also links to some testimonies, including this one guy’s particular approach. We’ll include it here because it gives an unusual amount of detail about purchasing and preparation:  

If your time is valuable to purchase organic, because you will not need to peel the potatoes, plus they have more nutrition. If you want to save money, purchase non-organic. I cycle between both options.

The three most common options for potatoes are going to be red, yellow, and russet. 98% of the time I will purchase red or yellow. They hold up much better structurally when you take them in and out of the refrigerator over a day or two.

Russet potatoes get mushy quickly. The only time I get Russet is if I get a really good price and I know I’m doing a strict potato hack, so I’m not using those potatoes two days later.

I’ve boiled so many potatoes in the last two years, my hands have developed muscle memory as if I were driving a manual car. Here is how I’ve optimized my potato preparation.

1. Peel directly into colander if the potatoes are not organic.

2. Place the potato directly into the cleaned and dried storage container.

3. Fill the storage container. When I first started hacking, I would weigh the potatoes. Once I figured out my container could hold 5.5 pounds, then I put my scale away.

4. Remove each potato. If it is small, place it in a stockpot, otherwise chop it into parts. For me, a medium potato is 2 or 3 parts. A large potato will be more. My goal is to have approximately equal size potato parts. I want them to boil at the same rate.

5. Once that is complete, I rinse the potatoes in the stockpot.

6. Refill stockpot with clean water and boil.

7. While the potatoes are boiling, empty peels in a compost bin.

8. Boil until done to your liking. I tend to cook mine a little longer than Tim Steele describes in his book The Potato Hack, but whatever you like is the right answer. Experiment.

9. Drain and let potatoes cool. The reason I want the potatoes to cool is that if I don’t, the steam will collect on the roof of the storage container and drain down onto the potatoes, making them mushy more quickly. If I want the potatoes to cool fast, I will spread them on a cookie sheet and place them outside (provided outside is cooler than inside).

10 Put the cooled potatoes in the storage bin and refrigerate.

That is my optimized path. I’m sure you’ll find your own.

Peer Review: Obesity II – Establishing Causal Links Between Chemical Exposures and Obesity

A new paper, called Obesity II: Establishing Causal Links Between Chemical Exposures and Obesity, was just published in the journal Biochemical Pharmacology (available online as of 5 April 2022). Authors include some obesity bigwigs like Robert H. Lustig, and it’s really long, so we figured it might be important. 

The title isn’t some weird Walden II reference — there’s a Part I and Part III as well. Part I reviews the obesity epidemic (in case you’re not already familiar?) and argues that obesity “likely has origins in utero.”

“The obesity epidemic is Kurt Cobain’s fault” is an unexpected but refreshing hypothesis

Part III basically argues that we should move away from doing obesity research with cells isolated in test tubes (probably a good idea TBH) and move towards “model organisms such as Drosophila, C. elegans, zebrafish, and medaka.” Sounds fishy to us but whatever, you’re the doctor.

This paper, Part II, makes the case that environmental contaminants “play a vital role in” the obesity epidemic, and presents the evidence in favor of a long list of candidate contaminants. We’re going to stick with Part II today because that’s what we’re really interested in.

For some reason the editors of this journal have hidden away the peer reviews instead of publishing them alongside the paper, like any reasonable person would. After all, who could possibly evaluate a piece of research without knowing what three anonymous faculty members said about it? The editors must have just forgotten to add them. But that’s ok — WE are these people’s peers as well, so we would be happy to fill the gap. Consider this our peer review:

This is an ok paper. They cite some good references. And they do cite a lot of references (740 to be exact), which definitely took some poor grad students a long time and should probably count for something. But the only way to express how we really feel is:

Seriously, 43 authors from 33 different institutions coming together to tell you that “ubiquitous environmental chemicals called obesogens play a vital role in the obesity pandemic”? We could have told you that a year ago, on a budget of $0. 

This wasted months, maybe years of their lives, and millions of taxpayer dollars making this paper that is just like, really boring and not very good. Meanwhile we wrote the first draft of A Chemical Hunger in a month (pretty much straight through in October 2020) and the only reason you didn’t see it sooner was because we were sending drafts around to specialists to make sure there wasn’t anything major that we overlooked (there wasn’t).

We don’t want to pick on the actual authors because, frankly, we’re sure this paper must have been a nightmare to work on. Most of the authors are passengers of this trainwreck — involved, but not responsible. We blame the system they work under.

We hope this doesn’t seem like a priority dispute. We don’t claim priority for the contamination hypothesis — here are four papers from 2008, 2009, 2010, and 2014, way before our work on the subject, all arguing in favor of the idea that contaminants cause obesity. If the contamination hypothesis turns out to be right, give David B. Allison the credit, or maybe someone even earlier. We just think we did an exceptionally good job making the case for the hypothesis. Our only original contributions (so far) are arguing that the obesity epidemic is 100% (ok, >90%) caused by contaminants, and suggesting lithium as a likely candidate. 

So we’re not trying to say that these authors are a bunch of johnny-come-latelies (though they kind of are, you see the papers up there from e.g. 2008?). The authors are victims here of a vicious system that has put them in such a bad spot that, for all their gifts, they can now only produce rubbish papers, and we think they know this in their hearts. It’s no wonder grad students are so depressed! 

So to us, this paper looks like a serious condemnation of the current academic system, and of the medical research system in particular. And while we don’t want to criticize the researchers, we do want to criticize the paper for being an indecisive snoozefest.

Long Paper is Long

The best part of this paper is that comes out so strongly against “traditional wisdom” about the obesity epidemic:  

The prevailing view is that obesity results from an imbalance between energy intake and expenditure caused by overeating and insufficient exercise. We describe another environmental element that can alter the balance between energy intake and energy expenditure: obesogens. … Obesogens can determine how much food is needed to maintain homeostasis and thereby increase the susceptibility to obesity. 

In particular we like how they point out how, from the contaminant perspective, measures of how much people eat are just not that interesting. If chemicals in your carpet raise your set point, you may need to eat more just to maintain homeostasis, and you might get fat. This means that more consumption, of calories or anything else you want to measure, is consistent with contaminants causing obesity. We made the same point in Interlude A. Anyways, don’t come at us about CICO unless you’ve done your homework. 

We also think the paper’s heart is in the right place in terms of treatment: 

The focus in the obesity field has been to reduce obesity via medicines, surgery, or diets. These interventions have not been efficacious as most people fail to lose weight, and even those who successfully lose substantial amounts of weight regain it. A better approach would be to prevent obesity from occurring in the first place. … A significant advantage of the obesogen hypothesis is that obesity results from an endocrine disorder and is thus amenable to a focus on prevention. 

So for this we say: preach, brothers and sisters.

The rest of the paper is boring to read and inconclusive. If you think we’re being unfair about how boring it is, we encourage you to go try to read it yourself.

Specific Contaminants

The paper doesn’t even do a good job assessing the evidence for the contaminants it lists. For example, glyphosate. Here is their entire review:

Glyphosate is the most used herbicide globally, focusing on corn, soy and canola [649]. Glyphosate was negative in 3T3-L1 adipogenic assays [650], [651]. Interestingly, three different formulations of commercial glyphosate, in addition to glyphosate itself, inhibited adipocyte proliferation and differentiation from 3T3-L1 cells [651]. There are also no animal studies focusing on developmental exposure and weight gain in the offspring. An intriguing study exposed pregnant rats to 25mg/kg/day during days 8-14 of gestation [652]. The offspring were then bred within the lineage to generate F2 offspring and bread to generate the F3 progeny. About 40% of the males and females of the F2 and F3 had abdominal obesity and increased adipocyte size revealing transgenerational inheritance. Interestingly, the F1 offspring did not show these effects. These results need verification before glyphosate can be designated as an obesogen.

For comparison, here’s our review of glyphosate. We try to, you know, come to a conclusion. We spend more than a paragraph on it. We cite more than four sources.

We cite their [652] as well, but we like, ya know, evaluate it critically and in the context of other exposure to the same compound. We take a close look at our sources, and we tell the reader we don’t think glyphosate is a major contributor to the obesity epidemic because the evidence doesn’t look very strong to us. This is bare-bones due diligence stuff. Take a look: 

The best evidence for glyphosate causing weight gain that we could find was from a 2019 study in rats. In this study, they exposed female rats (the original generation, F0) to 25 mg/kg body weight glyphosate daily, during days 8 to 14 of gestation. There was essentially no effect of glyphosate exposure on these rats, or in their children (F1), but there was a significant increase in the rates of obesity in their grandchildren (F2) and great-grandchildren (F3). There are some multiple comparison issues, but the differences are relatively robust, and are present in both male and female descendants, so we’re inclined to think that there’s something here. 

There are a few problems with extending these results to humans, however, and we don’t just mean that the study subjects are all rats. The dose they give is pretty high, 25 mg/kg/day, in comparison to (again) farmers working directly with the stuff getting a dose closer to 0.004 mg/kg.

The timeline also doesn’t seem to line up. If we take this finding and apply it to humans at face value, glyphosate would only make you obese if your grandmother or great-grandmother was exposed during gestation. But glyphosate wasn’t brought to market until 1974 and didn’t see much use until the 1990s. There are some grandparents today who could have been exposed when they were pregnant, but obesity began rising in the 1980s. If glyphosate had been invented in the 1920s, this would be much more concerning, but it wasn’t.

Frankly, if they aren’t going to put in the work to engage with studies at this level, they shouldn’t have put them in this review. 

If this were a team of three people or something, that would be one thing. But this is 43 specialists working on this problem for what we assume was several months. We wrote our glyphosate post in maybe a week?

Some of the reviews are better than this — their review of BPA goes into more detail and cites a lot more studies. But the average review is pretty cruddy. For example, here’s the whole review for MSG:

Monosodium glutamate (MSG) is a flavor enhancer used worldwide. Multiple animal studies provided causal and mechanistic evidence that parenteral MSG intake caused increased abdominal fat, dyslipidemia, total body weight gain, hyperphagia and T2D by affecting the hypothalamic feeding center [622], [623], [624]. MSG increased glucagon-like peptide-1 (GLP-1) secretion from the pGIP/neo: STC-1 cell line indicating a possible action on the gastrointestinal (GI) tract in addition to its effects on the brain [625]. It is challenging to show similar results in humans because there is no control population due to the ubiquitous presence of MSG in foods. MSG is an obesogen.

Seems kind of extreme to unequivocally declare “MSG is an obesogen” on the basis of just four papers. On the basis of results that seem to be in mice, rats, mice, and cells in a test tube, as far as we can tell (two of the citations are review articles, which makes it hard for us to know what studies they specifically had in mind). Somehow this is enough to declare MSG a “Class I Obesogen” — Animal evidence: Strong. In vitro evidence: Strong. Regulatory action: to be banned. Really? 

Instead, we support the idea of — thinking about it for five minutes. For example, MSG occurs naturally in many foods. If MSG were a serious obesogen, tomatoes and dashi broth would both make you obese. Why are Italy and Japan not more obese? The Japanese first purified MSG and they love it so much, they have a factory tour for the stuff that is practically a theme park — “there is a 360-degree immersive movie experience, a diorama and museum of factory history, a peek inside the fermentation tanks (yum!), and finally, an opportunity to make and taste your own MSG seasoning.” Yet Japan is one of the leanest countries in the world.

As far as we can tell, Asia in general consumes way more MSG than any other part of the world. “Mainland China, Indonesia, Vietnam, Thailand, and Taiwan are the major producing countries in Asia.” Why are these countries not more obese? MSG first went on the market in 1909. Why didn’t the obesity epidemic start then? We just don’t think it adds up. 

(Also kind of weird to put this seasoning invented in Asia, and most popular in Asia, under your section on “Western diet.”)

Adapted from Fig. 3

Let’s also look at their section on DDT. This one, at least, is several paragraphs long, so we won’t quote it in full. But here’s the summary: 

A 2017 systematic review of in vitro, animal and epidemiological data on DDT exposures and obesity concluded the evidence indicated that DDT was “presumed” to be obesogenic for humans [461]. The in vitro and animal data strongly support DDT as an obesogen. Based on the number of positive prospective human studies, DDT is highly likely to be a human obesogen. Animal and human studies showed obesogenic transmission across generations. Thus, a POP banned almost 50 years ago is still playing a role in the current obesity pandemic, which indicates the need for caution with other chemical exposures that can cause multigenerational effects.

We’re open to being convinced otherwise, but again, this doesn’t really seem to add up. DDT was gradually banned across different countries and was eventually banned worldwide. Why do we not see reversals or lags in the growth of obesity in those countries those years? They mention that DDT is still used in India and Africa, sometimes in defiance of the ban. So why are obesity rates in India and Africa so low? We’d love to know what they think of this and see it contextualized more in terms of things like occupation and human exposure timeline.

Review Paper

With a long list of chemicals given only the briefest examination, it’s hard not to see this paper as overly inclusive to the point of being useless. It makes the paper feel like a cheap land grab to stake a claim to being correct in the future if any of the chemicals on the list pan out.

Maybe their goal is just to list and categorize every study that has ever been conducted that might be relevant. We can sort of understand this but — why no critical approach to the material? Which of these studies are ruined by obvious confounders? How many of them have been p-hacked to hell? Seems like the kind of thing you would want to know! 

You can’t just list papers and assume that it will get you closer to understanding. In medicine, the reference for this problem is Ioannidis’s Why Most Published Research Findings Are False. WMPRFAF was published in 2005, you don’t have an excuse for not thinking critically about your sources.

Despite this, they don’t even mention lithium, which seems like an oversight. 

Oh right, Kurt Cobain IS responsible for the obesity epidemic

We wish the paper tried to provide a useful conclusion. It would have been great to read them making their best case for pretty much anything. Contaminants are responsible for 50% of the epidemic. Contaminants are responsible for no more than 10% of the epidemic. Contaminants are responsible for more than 90% of the epidemic. We think phthalates are the biggest cause. We think DDT is the biggest cause. We think it’s air pollution and atrazine. Make a case for something. That would be cool.

What is not cool is showing up being like: Hey we have a big paper! The obesity epidemic is caused by chemicals, perhaps, in what might possibly be your food and water, or at work, though if it’s not, they aren’t. This is a huge deal if this is what caused the epidemic, possibly, unless it didn’t. The epidemic is caused by any of these several dozen compounds, unless it’s just one, or maybe none of them. What percentage of the epidemic is caused by these compounds? It’s impossible to say. But if we had to guess, somewhere between zero and one hundred percent. Unless it isn’t. 

Effect Size

The paper spends almost no time talking about effect size, which we think is 1) a weird choice and 2) the wrong approach for this question. 

We don’t just care about which contaminants make you gain weight. We care about which contaminants make you gain a concerning amount of weight. We want to know which contaminants have led to the ~40 lbs gain in average body weight since 1970, not which of them can cause 0.1 lbs of weight gain if you’re inhaling them every day at work. These differences are more than just important, they’re the question we’re actually interested in!

For comparison: coffee and airplane travel are both carcinogens, but they increase your risk of cancer by such a small degree that it’s not even worth thinking about, unless you’re a pilot with an espresso addiction. When the paper says “Chemical ABC is an obesogen”, it would be great to see some analysis of whether it’s an obesogen like how getting 10 minutes of sunshine is a carcinogen, or whether it’s an obesogen like how spending a day at the Chernobyl plant is a carcinogen. Otherwise we’re on to “bananas are radioactive” levels of science reporting — technically true, but useless and kind of misleading.

The huge number of contaminants they list does seem like a mark in favor of a “the obesity epidemic is massively multi-causal” hypothesis (which we discussed a bit in this interview), but again it’s hard to tell without seeing a better attempt to estimate effect sizes. The closest thing to an estimate that we saw was this line: “Population attributable risk of obesity from maternal smoking was estimated at 5.5% in the US and up to 10% in areas with higher smoking rates”.

Stress Testing

Their conclusion is especially lacking. It’s one thing to point out that what we’re studying is hard, but it’s another thing to deny the possibility of victory. Let’s look at a few quotes:

“A persistent key question is what percent of obesity is due to genetics, stress, overnutrition, lack of exercise, viruses, drugs or obesogens? It is virtually impossible to answer that question for any contributing factors… it is difficult to determine the exact effects of obesogens on obesity because each chemical is different, people are different, and exposures vary regionally and globally.”

Imagine going to an oncology conference and the keynote speaker gets up and says, “it is difficult to determine the exact effects of radiation on cancer because each radiation source is different, people are different, and exposures vary regionally and globally”. While much of this is true, oncologists don’t say this sort of thing (we hope?) because they understand that while the problem is indeed hard, it’s important, and hold out hope that solving that problem is not “virtually impossible”. Indeed, we’re pretty sure it’s not. 

They’re pretty pessimistic about future research options:

“We cannot run actual ‘clinical trials’ where exposure to obesogens and their effects are monitored over time. Thus, we focus on assessing the strength of the data for each obesogen.”

Assessing the strength of the data is a good idea, but this is leaving a lot on the table. Natural experiments are happening all the time, and you don’t need clinical trials to infer causality. We’d like to chastise this paper with the following words:

[Before] we set about instructing our colleagues in other fields, it will be proper to consider a problem fundamental to our own. How in the first place do we detect these relationships between sickness, injury and conditions of work? How do we determine what are physical, chemical and psychological hazards of occupation, and in particular those that are rare and not easily recognized?

There are, of course, instances in which we can reasonably answer these questions from the general body of medical knowledge. A particular, and perhaps extreme, physical environment cannot fail to be harmful; a particular chemical is known to be toxic to man and therefore suspect on the factory floor. Sometimes, alternatively, we may be able to consider what might a particular environment do to man, and then see whether such consequences are indeed to be found. But more often than not we have no such guidance, no such means of proceeding; more often than not we are dependent upon our observation and enumeration of defined events for which we then seek antecedents.

… However, before deducing ‘causation’ and taking action we shall not invariably have to sit around awaiting the results of the research. The whole chain may have to be unraveled or a few links may suffice. It will depend upon circumstances.

Sir Austin Bradford Hill said that, and we’d say he knows a little more about clinical trials than you do, pal, because HE INVENTED THEM. And then he perfected them so that no living physician could best him in the Ring of Honor– 

So we think the “no clinical trials” thing is a non-issue. Sir Austin Bradford Hill and colleagues were able to discover the connection between cigarette smoking and lung cancer without forcing people to smoke more than they were already smoking. You really can do medical research without clinical trials.

They did not do this

But even so, the paper is just wrong. We can run clinical trials. People do occasionally lose weight, sometimes huge amounts of weight. So we can try removing potential obesogens from the environment and seeing if that leads to weight loss. If we do it in a controlled manner, we can get some pretty strong evidence about whether or not specific contaminants are causing obesity.

Defeatism

Our final and biggest problem with this paper is that it is so tragically defeatist. It leaves you totally unsure as to what would be informative additional research. It doesn’t show a clear path forward. It’s pessimistic. And it’s tedious as hell. All of this is bad for morale. 

The paper’s suggestions seem like a list of good ways to spend forever on this problem and win as many grants as possible. This seems “good” for the scientists in the narrow sense that it will help them keep their tedious desk jobs, jobs which we think they all secretly hate. It’s “good” in that it lets you keep playing what Erik Hoel describes as “the Science Game” for as long as possible:

When you have a lab, you need grant money. Not just for yourself, but for the postdoctoral researchers and PhDs who depend on you for their livelihoods. … much of what goes on in academia is really the Science Game™. … varying some variable with infinite degrees of freedom and then throwing statistics at it until you get that reportable p-value and write up a narrative short story around it.

Think of it like grasping a dial, and each time you turn it slightly you produce a unique scientific publication. Such repeatable mechanisms for scientific papers are the dials everyone wants. Playing the Science Game™ means asking a question with a slightly different methodology each time, maybe throwing in a slightly different statistical analysis. When you’re done with all those variations, just go back and vary the original question a little bit. Publications galore.

If this is your MO, then “more research is needed” is the happiest sound in the world. Actually solving a problem, on the other hand, is kind of terrifying. You would need to find a new thing to investigate! It’s much safer to do inconclusive work on the same problem for decades.

This is part of why we find the suggestion to move towards research with “model organisms such as Drosophila, C. elegans, zebrafish, and medaka” so suspicious. Will this solve the obesity epidemic? Probably not, and certainly not any time this decade. Will it allow you to generate a lot of different papers on exposing Drosophila, C. elegans, zebrafish, and medaka to slightly different amounts of every chemical imaginable? Absolutely.

(As Paul Graham describes, “research must be substantial– and awkward systems yield meatier papers, because you can write about the obstacles you have to overcome in order to get things done. Nothing yields meaty problems like starting with the wrong assumptions.’”)

With all due respect to this approach, we do NOT want to work on obesity for the rest of our lives. We want to solve obesity in the next few years and move on to something else. We think that this is what you want to happen too! Wouldn’t it be nice to at least consider that we might make immediate progress on serious problems? What ever happened to that? 

Political Scientist Adolph Reed Jr. once wrote that modern liberalism has no particular place it wants to go. “Its métier,” he said, “is bearing witness, demonstrating solidarity, and the event or the gesture. Its reflex is to ‘send messages’ to those in power, to make statements, and to stand with or for the oppressed. This dilettantish politics is partly the heritage of a generation of defeat and marginalization, of decades without any possibility of challenging power or influencing policy.“

In this paper, we encounter a scientific tradition that no longer has any place it wants to go (“curing obesity? what’s that?”), that makes stands but has a hard time imagining taking action, that is the heir to a generation of defeat and marginalization. All that remains is a reflex of bearing witness to suffering. 

We think research can be better than this. That it can be active and optimistic. That it can dare to dream. That it can make an effort to be interesting. 

Why do we keep complaining about this paper being boring? Why does it matter? It matters because when the paper is boring, it suggests that the idea that obesity is caused by contaminants isn’t important enough to bother spending time on the writing. It suggests people won’t be interested to read the paper, that no one cares, that no care should be taken in the discussion. That nothing can be gained by thinking clearly about these ideas. It suggests that the prospect of curing obesity isn’t exciting. But we think that the prospect of curing obesity is very exciting, and we hope you do too!

The Only True Wisdom is Knowing that You Can’t Draw a Bicycle

I. 

Early on in science there would never even could be a replication crisis or anything because everyone was just trying all the stuff. They were writing letters to each other with directions, trying each others’ studies, and seeing what they could confirm for themselves.  

Today, scientists would tell you that replicating someone else’s work takes decades of specialized training, because most findings are too subtle and finicky to be reproduced by just anyone. For example, consider this story from Harvard psychology professor Jason Mitchell, about how directions depend on implicit knowledge, and it’s impossible to fully explain your procedure to anyone:

I have a particular cookbook that I love, and even though I follow the recipes as closely as I can, the food somehow never quite looks as good as it does in the photos. Does this mean that the recipes are deficient, perhaps even that the authors have misrepresented the quality of their food? Or could it be that there is more to great cooking than just following what’s printed in a recipe? I do wish the authors would specify how many millimeters constitutes a “thinly” sliced onion, or the maximum torque allowed when “fluffing” rice, or even just the acceptable range in degrees Fahrenheit for “medium” heat. They don’t, because they assume that I share tacit knowledge of certain culinary conventions and techniques; they also do not tell me that the onion needs to be peeled and that the chicken should be plucked free of feathers before browning. … Likewise, there is more to being a successful experimenter than merely following what’s printed in a method section. Experimenters develop a sense, honed over many years, of how to use a method successfully. Much of this knowledge is implicit.

Mitchell believes in a world where findings are so fragile that only extreme insiders, close collaborators of the original team, could possibly hope to reproduce their findings. The implicit message here is something like, “don’t bother replicating ever; please take my word for my findings.” 

The general understanding of replication is slightly less extreme. To most researchers, replication is when one group of scientists at a major university reproduce the work of another group of scientists at a different major university. There’s also a minority position that replications should be done by many labs, that replication is an internal process of double-checking: “take the community’s word”. 

But this doesn’t seem quite right to us either. If a finding can’t be confirmed by outsiders like you — if you can’t see it for yourself — it doesn’t really “count” as replication. This used to be the standard of evidence (confirm it for yourself or don’t feel bound to take it seriously) and we think this is a better standard to hold ourselves to.

It’s not that Mitchell is wrong — he’s right, there is a lot of implicit knowledge involved in doing anything worth doing. Sometimes science is really subtle and hard to replicate at home; other times, it isn’t. But whether or not a particular study is easy or hard to replicate is a dodge. This argument is a load of crap because the whole reason to do research in the first place is a fight against received wisdom.

The motto of the Royal Society, one of the first scientific societies, was and still is nullius in verba. Roughly translated, this means, “take no one’s word” or “don’t take anyone’s word for it”. We think this is a great motto. It’s a good summary of the kind of spirit you need to investigate the world. You have the right to see for yourself and make up your own mind; you shouldn’t have to take someone’s word. If you can take someone else’s word for it — a king, maybe — then why bother? 

In the early 1670s, Antonie van Leeuwenhoek started writing to the Royal Society, talking about all the “little animals” he was seeing in drops of pond water when he examined them under his new microscopes. Long particles with green streaks, wound about like serpents, or the copper tubing in a distillery. Animals fashioned like tiny bells with long tails. Animals spinning like tops, or shooting through the water like pikes. “Little creatures,” he said, “above a thousand times smaller than the smallest ones I have ever yet seen upon the rind of cheese.”

Wee beasties

Naturally, the Royal Society found these reports a little hard to believe. They had published some of van Leewenhoek’s letters before, so they had some sense of who the guy was, but this was almost too much:

Christiaan Huygens (son of Constanijn), then in Paris, who at that time remained sceptical, as was his wont: ‘I should greatly like to know how much credence our Mr Leeuwenhoek’s observations obtain among you. He resolves everything into little globules; but for my part, after vainly trying to see some of the things which he sees, I much misdoubt me whether they be not illusions of his sight’. The Royal Society tasked Nehemiah Grew, the botanist, to reproduce Leeuwenhoek’s work, but Grew failed; so in 1677, on succeeding Grew as Secretary, Hooke himself turned his mind back to microscopy. Hooke too initially failed, but on his third attempt to reproduce Leeuwenhoek’s findings with pepper-water (and other infusions), Hooke did succeed in seeing the animalcules—‘some of these so exceeding small that millions of millions might be contained in one drop of water’ 

People were skeptical and didn’t take van Leewenhoek at his word alone. They tried to get the same results, to see these little animals for themselves, and for a number of years they failed. They got no further help from van Leewenhoek, who refused to share his methods, or the secrets of how he made his superior microscopes. Yet even without a precise recipe, Hooke was eventually able to see the tiny, wonderful creatures for himself. And when he did, van Leewenhoek became a scientific celebrity almost overnight. 

If something is the truth about how the world works, the truth will come out, even if it takes Robert Hooke a few years to confirm your crazy stories about the little animals you saw in your spit. Yes, research is very exacting, and can demand great care and precision. Yes, there is a lot of implicit knowledge involved. The people who want to see for themselves might have to work for it. But if you think what you found is the real McCoy, then you should expect that other people should be able to go out and see it for themselves. And assuming you are more helpful than van Leewenhoek, you should be happy to help them do it. If you don’t think people will be able to replicate it at their own bench, are you sure you think you’ve discovered something?

Fast forward to the early 1900s. Famous French Physicist Prosper-René Blondlot is studying the X-Rays, which had been first described by Wilhelm Röntgen in 1895. This was an exciting time for rays of all stripes — several forms of invisible radiation had just been discovered, not only X-Rays but ultraviolet light, gamma rays, and cathode rays. 

Also he looked like a wizard

So Blondlot was excited, but not all that surprised, when he discovered yet another new form of radiation. He was firing X-rays through a quartz prism and noticed that a detector was glowing when it shouldn’t be. He performed more experiments and in 1903 he announced the discovery of: N-rays!  

Blondlot was a famous physicist at a big university in France, so everyone took this seriously and they were all very excited. Soon other scientists had replicated his work in their own labs and were publishing scores of papers on the subject. They began documenting the many strange properties of N-rays. The new radiation would pass right through many substances that blocked light, like wood and aluminum, but were obstructed by water, clouds, and salt. They were emitted by the sun and by human bodies (especially flexed muscles and certain areas of the brain), as well as rocks that had been left in the sun and been allowed to “soak up” the N-rays from sunlight. 

The procedure for detecting these rays wasn’t easy. You had to do everything just right — you had to use phosphorescent screens as detectors, you had to stay in perfect darkness for a half hour so your eyes could acclimate, etc. Fortunately Blondlot was extremely forthcoming and always went out of his way to help provide these implicit details he might not have been able to fit in his reports. And he was vindicated, because with his help, labs all over the place were able to reproduce and extend his findings.

Well, all over France. Some physicists outside France, including some very famous ones, weren’t able to reproduce Blondlot’s findings at all. But as before, Blondlot was very forthcoming and did his best to answer everyone’s questions. 

Even so, over time some of the foreigners began to get a little suspicious. Eventually some of them convinced an American physicist, Robert W. Wood, to go visit Blondlot in France to see if he could figure out what was going on. 

What a dude. Classic American

Blondlot took Wood in and gave him several demonstrations. To make a long story short (you can read Wood’s full account here; it’s pretty interesting), Wood found a number of problems with Blondlot’s experiments. The game was really up when Wood secretly removed a critical prism from one of the experiments, and Blondlot continued reporting the same results as if nothing had happened. Wood concluded that N-rays and all the reports had been the work of self-deception, calling them “purely imaginary”. Within a couple of years, no one believed in N-rays anymore, and today they’re seen as a cautionary tale. 

So much for the subtlety and implicit knowledge needed to do cutting-edge work. Maybe your results are hard to get right, but maybe if other people can’t reproduce your findings, they shouldn’t take your word for it.

This is the point of all those chemistry sets your parents (or cool uncle) gave you when you were a kid. This is the point of all those tedious lab classes in high school. They were poorly executed and all but this was the idea. If whatever Röntgen or Pasteur or Millikan or whoever found is for real, you should be able to reproduce the same thing for yourself in your high school with only the stoner kid for a lab assistant (joke’s on you, stoners make great chemists — they’re highly motivated).

Some people will scoff. After all, what kind of teenager can replicate the projects reported in a major scientific journal? Well, as just one example, take Dennis Gabor: “during his childhood in Budapest, Gabor showed an advanced aptitude for science; in their home laboratory, he and his brother would often duplicate the experiments they read about in scientific journals.”

Clearly some studies will be so complicated that Hungarian teenagers won’t be able to replicate them, or may require equipment they don’t have access to. And of course the Gabor brothers were not your average teenagers. But it used to be possible, and it should be made possible whenever possible. Because otherwise you are asking the majority of people to take your claims on faith. If a scientist is choosing between two lines of work of equal importance, one that requires a nuclear reactor and the other that her neighbor’s kids can do in their basement, she should go with the basement.

It’s good if one big lab can recreate what another big lab claims to have found. But YOU are under no obligation to believe it unless you can replicate it for yourself.

You can of course CHOOSE to trust the big lab, look at their report and decide for yourself. But that’s not really replication. It’s taking someone’s word for something. 

There’s nothing wrong with taking someone’s word; you do it all the time. Some things you can’t look into for yourself; and even if you could, you don’t have enough time to look into everything. So we are all practical people and take the word of people we trust for lots of things. But that’s not replication.

Something that you personally can replicate is replication. Watching someone else do it is also pretty close, since you still get to see it for yourself. Something that a big lab would be able to replicate is not really replication. It’s nice to have confirmation from a second lab, but now you’re just taking two people’s word for it instead of one person’s. Something that can in principle be replicated, but isn’t practical for anyone to actually attempt, is not replication at all.

If it cannot be replicated even in principle, then what exactly do you think you’re doing? What exactly do you think you’ve discovered here? 

What ever happened to all the public science demonstrations

We find it kind of concerning that “does replicate” or “doesn’t replicate” have come to be used as synonyms of “true” and “untrue”. It’s not enough to say that things replicate or not. Blondlot’s N-ray experiments were replicated hundreds of times around France, until all of a sudden they weren’t; van Leeuwenhoek’s observations of tiny critters in pond water weren’t replicated for years, until they were. The modern take on replication (lots of replications from big labs = good) would have gotten both of these wrong. 

II.

If knowing the truth about some result is important to you, don’t just take someone’s word for it. Don’t leave it up to the rest of the world to do this work; we’re all bunglers, you should know that. If you can, you should try it for yourself.

So let’s look at some examples of REAL replication. We’ll take our examples from psychology, since as we saw earlier, they’re in the thick of the modern fight over replication.

We also want to take a minute to defend the psychologists, at least on the topic of replication (psychology has other sins, but that’s a subject for another time). Psychology has gotten a lot of heat for being the epicenter of the replication crisis. Lots of psychology studies haven’t replicated under scrutiny. There have been many high-profile disputes and attacks. Lots of famous findings seem to be made out of straw

Some people have taken this as a sign that psychology is all bunkum. They couldn’t be more wrong — it’s more like this. One family in town gets worried and hires someone to take a look at their house. The specialist shows up and sure enough, their house has termites. Some of the walls are unsafe; parts of the structure are compromised. The family is very worried but they start fumigating and replacing boards that the termites have damaged to keep their house standing. All the other families in town laugh at them and assume that their house is the most likely to fall down. But the opposite is true. No other family has even checked their home for termites; but if termites are in one house in town, they are in other houses for sure. The first family to check is embarrassed, yes, but they’re also the only family who is working to repair the damage.

The same thing is going on in psychology. It’s very embarrassing for the field to have their big mistakes aired in public; but psychology is also distinct for being the first field willing to take a long hard look at themselves and make a serious effort to change for the better. They haven’t done a great job, but they’re one of the only fields that is even trying. We won’t name names but you can bet that other fields have just as many problems with p-hacking — the only difference is that those fields are doing a worse job rooting it out. 

The worst thing you can say about psychology is that it is still a very young field. But try looking at physics or chemistry when they were only 100 years old, and see how well they were doing. From this perspective, psychology is doing pretty ok. 

Despite setbacks, there has been some real progress in psychology. So here are a few examples of psychological findings that can actually be replicated, by any independent researcher in an afternoon. You don’t have to take our word or anyone else’s word for these findings if you don’t want to. Try it for yourself! Please do try this at home, that’s the point.

Are these the most important psychology findings? Probably not — we picked them because they’re easy to replicate, and you should be able to confirm their results from your sofa (disclaimer: for some of them, you may have to leave your sofa). But all of them are things we didn’t know about 150 years ago, so they represent a real advance in what we know about the mind.

For most of these you will need a small group of people, because most of these are statistically true results, not guaranteed to work in every case. But as long as you have a dozen people or so, they should be pretty reliable.

Draw a Bicycle — Here’s a tricky one you can do all on your own. You’ve seen a bicycle before, right? You know what they look like? Ok, draw one. 

Unless you’re a bicycle mechanic, chances are you’ll be really rubbish at this — most people are. While you can recognize a bicycle no problem, you don’t actually know what one looks like. Most people produce drawings that look something like this:

Needless to say, that’s not a good representation of the average bicycle.

Seriously, try this one yourself right now. Don’t look up what a bicycle looks like; draw it as best you can from memory and see what you get. We’ll put a picture of what a bicycle actually looks like at the end of this post. 

Then, tweet your bicycle drawings at us at @mold_time on twitter

(A similar example: which of the images below shows what a penny looks like?)

Wisdom of the CrowdWisdom of the crowd refers to the fact that people tend to make pretty good guesses on average even when their individual guesses aren’t that good. 

You can do this by having a group of people guess how many jellybeans are in a jar of jellybeans, or how much an ox weighs. If you average all the guesses together, most of the time it will be pretty close to the right answer. But we’ve found it’s more fun to stand up there and ask everyone to guess your age.

We’ve had some fun doing this one ourselves, it’s a nice trick, though you need a group of people who don’t know you all that well. It works pretty well in a classroom. 

This only works if everyone makes their judgments independently. To make sure they don’t influence each other’s guesses, have them all write down their guesses on a piece of paper before blurting it out. 

Individual answers are often comically wrong — sometimes off by up to a decade in both directions — but we’ve been very impressed. In our experience the average of all the guesses is very accurate, often to within a couple of months. But give it a try for yourself.

Emotion in the Face — You look at someone’s face to see how they’re feeling, right? Well, maybe. There’s a neat paper from a few years ago that has an interesting demonstration of how this isn’t always true. 

They took photos of tennis players who had just won a point or who had just lost a point, and cut apart their faces and bodies (in the photos; no tennis pros were harmed, etc.). Then they showed people just the bodies or just the faces and asked them to rate how positively or negatively the person was feeling:

They found that people could usually tell that a winning body was someone who was feeling good, and a losing body was someone feeling bad. But with just the faces, they couldn’t tell at all. Just look above – for just the bodies, which guy just won a point? How about for the faces, who won there?

Then they pushed it a step further by putting winning faces on losing bodies, and losing faces on winning bodies, like so:

Again, the faces didn’t seem to matter. People thought chimeras with winning bodies felt better than chimeras with losing bodies, and seemed to ignore the faces.

This one should be pretty easy to test for yourself. Go find some tennis videos on the internet, and take screenshots of the players when they win or lose a point. Cut out the faces and bodies and show them to a couple friends, and ask them to rate how happy/sad each of the bodies and faces seems, or to guess which have just won a point and which have just lost. You could do this one in an afternoon. 

Anchoring — This one is a little dicey, and you’ll need a decent-sized group to have a good chance of seeing it. 

Ask a room of people to write down some number that will be different for each of them — like the last four digits of their cell phone number, or the last two digits of their student ID or something. Don’t ask for part of their social security number or something that should be kept private. 

Let’s assume it’s a classroom. Everyone takes out their student ID and writes down the last two digits of their ID number. If your student ID number is 28568734, you write down “34”.

Now ask everyone to guess how old Mahatma Gandhi was when he died, and write that down too. If this question bores you, you can ask them something else — the average temperature in Antarctica, the average number of floors in buildings in Manhattan, whatever you like.

Then ask everyone to share their answers with you, and write them on the board. You should see that people who have higher numbers as the last two digits of their student ID number (e.g. 78 rather than 22) will guess higher numbers for the second question, even though the two numbers are unrelated. They call this anchoring. You can plot the student ID digits and the estimates of Gandhi’s age on a scatterplot if you like, or even calculate the correlation. It should come out positive.

Inattentional Blindness — If you’ve taken an intro psych class, then you’re familiar with the “Invisible Gorilla” (for everyone else, sorry for spoiling). In the biz they call this “inattentional blindness” — when you aren’t paying attention, or your attention is focused on one task, you miss a lot of stuff.

Turns out this is super easy to replicate, especially a variant called “change blindness”, where you change something but people don’t notice. You can swap out whole people and about half the time, no one picks up on it.

Because it’s so easy, people love to replicate this effect. Like this replication from NOVA, or this British replication, or this replication from National Geographic. You can probably find a couple more on YouTube if you dig around a bit. 

This one isn’t all that easy to do at home, but if you can find a couple accomplices and you’re willing to play a prank on some strangers, you should be able to pull it off. 

(Or you can replicate it in yourself by playing I’m on Observation Duty.)

False Memory — For this task you need a small group of people. Have them put away their phones and writing tools; no notes. Tell them you’re doing a memory task — you’ll show them a list of words for 30 seconds, and you want them to remember as many words as possible. 

Then, show them the following list of words for 30 seconds or so: 

After 30 seconds, hide or take down the list. 

Then, wait a while for the second half of the task. If you’re doing this in a classroom, do the first step at the beginning of class, and the second half near the end.

Anyways, after waiting at least 10 minutes, show them these words and ask them, which of the words was on the original list? 

Most people will incorrectly remember “sleep” as being on the original list, even though, if you go back and check, it’s not. What’s going on here? Well, all of the words on the original list are related to sleep — sleep adjectives, sleep sounds, sleep paraphernalia — and this leads to a false memory that “sleep” was on the list as well. 

You can do the same thing for other words if you want — showing people a list of words like “sour”, “candy”, and “sugar” should lead to false memories of the word “sweet”. You can also read the list of words aloud instead of showing it on a screen for 30 seconds, you should get the same result either way. 

Draw your own conclusions about what this tells us about memory, but the effect should be pretty easy to reproduce for yourself.

We don’t think all false memory findings in psychology bear out. We think some of them aren’t true, like the famous Loftus & Palmer (1974) study, which we think is probably bullshit. But we do think it’s clear that it’s easy to create false memories under the right circumstances, and you can do it in the classroom using the approach we describe above.

You can even use something like the inattentional blindness paradigms above to give people false memories about their political opinions. A little on the tricky side but you should also be able to replicate this one if you can get the magic trick right. And if this seems incredible, ridiculous, unbelievable — try it for yourself! 

Oh yeah, and here’s that bicycle: 

The Scientific Virtues

Science education usually starts with teaching students different tools and techniques, methods for conducting research. 

This is wrong. Science education should begin with the scientific virtues. 

Teaching someone painting techniques without teaching them composition will lead to lifeless paintings. Giving business advice to someone who lacks civic duty will lead to parasitic companies. Teaching generals strategy without teaching them honor gets you warlords. So teaching someone the methods of science without teaching them the virtues will lead to dull, pointless projects. Virtue is the key to happy, creative, important, meaningful research.

The scientific virtues are:

  • Stupidity
  • Arrogance
  • Laziness
  • Carefreeness
  • Beauty
  • Rebellion
  • Humor

These virtues are often the opposite of the popular image of what a scientist should look like. People think scientists should be intelligent. But while it’s helpful to be clever, it’s more important to be stupid. People think scientists are authority figures. Really, scientists have to defy authority — the best scientists are one step (or sometimes zero steps) away from being anarchists. People think scientists are arrogant, and this is true, but we worry that scientists are not arrogant enough

Anyone who practices these virtues is a scientist, even if they work night shifts at the 7-11 and learned everything they know about statistics from twitter. Anyone who betrays these virtues is no scientist at all, even if they’ve got tenure at Princeton and have a list of publications long enough to run from Cambridge to New Haven.

Cultivating virtue is the most important way to become a better scientist. Many people want to be scientists but are worried that they are not smart enough, or not talented enough. It’s true that there is not much you can do to become smarter, and you are mostly stuck with the talents you were born with. But virtues can be cultivated infinitely — there is no limit to how good you can get at practicing them. Anyone can become a better scientist by practicing these virtues — maybe even a great scientist.

Stupidity

The great obstacle to discovering the shape of the earth, the continents, and the oceans was not ignorance, but the illusion of knowledge.

Daniel Boorstin

To a large extent, your skill as a researcher comes down to how well you understand how dumb you are, which is always “very”. Once you realize how stupid you are, you can start to make progress.

A different writer might say “humility” here rather than stupidity. But calling this virtue humility might make you feel smug and self-satisfied, which is not the right feeling at all. Instead, you should feel dumb. The virtue of stupidity is all about feeling like a tiny mote in a vast universe that you don’t understand even a little bit, and calling it humility doesn’t strike that note. 

Great scientists are not especially humble, as we shall see in just a minute. But they are stupid — they are practiced in practicing ignorance. They have cultivated the virtue of saying and doing things that are just entirely boneheaded, because this is vital to the process of discovery, and more important, it is relaxing and fun. 

It seems necessary to me, then, that all people at a session be willing to sound foolish and listen to others sound foolish.

Isaac Asimov

Stupidity is all about preparing you to admit when you’re facing a problem where you don’t know what is going on, which is always. This allows you to ask incredibly dumb questions at any time. 

People who don’t have experience asking stupid questions don’t understand how important they can be. Try asking more and dumber questions — lean in on how stupid you are. You will find the world opening up to you. Ignorant questions are revealing! 

I took mechanical drawing when I was in school, but I am not good at reading blueprints. So they unroll the stack of blueprints and start to explain it to me, thinking I am a genius. …

I’m completely dazed. Worse, I don’t know what the symbols on the blueprint mean! There is some kind of a thing that at first I think is a window. It’s a square with a little cross in the middle, all over the damn place. I think it’s a window, but no, it can’t be a window, because it isn’t always at the edge. I want to ask them what it is.

You must have been in a situation like this when you didn’t ask them right away. Right away it would have been OK. But now they’ve been talking a little bit too long. You hesitated too long. If you ask them now they’ll say, “What are you wasting my time all this time for?”

What am I going to do? I get an idea. Maybe it’s a valve. I take my finger and I put it down on one of the mysterious little crosses in the middle of one of the blueprints on page three, and I say, “What happens if this valve gets stuck?” — figuring they’re going to say, “That’s not a valve, sir, that’s a window.”

So one looks at the other and says, “Well, if that valve gets stuck –” and he goes up and down on the blueprint, up and down, the other guy goes up and down, back and forth, back and forth, and they both look at each other. They turn around to me and they open their mouths like astonished fish and say, “You’re absolutely right, sir.”

So they rolled up the blueprints and away they went and we walked out. And Mr. Zumwalt, who had been following me all the way through, said, “You’re a genius. I got the idea you were a genius when you went through the plant once and you could tell them about evaporator C-21 in building 90-207 the next morning,” he says, “but what you have just done is so fantastic I want to know how, how do you do that?”

I told him you try to find out whether it’s a valve or not.

Richard Feynman

Asking dumb questions was a particular favorite of Richard Feynman, who really cannot recommend it strongly enough: 

That was for me: I can’t understand anything in general unless I’m carrying along in my mind a specific example and watching it go. Some people think in the beginning that I’m kind of slow and I don’t understand the problem, because I ask a lot of these “dumb” questions: “Is a cathode plus or minus? Is an anion this way, or that way?”

But later, when the guy’s in the middle of a bunch of equations, he’ll say something and I’ll say, “Wait a minute! There’s an error! That can’t be right!”

The guy looks at his equations, and sure enough, after a while, he finds the mistake and wonders, “How the hell did this guy, who hardly understood at the beginning, find that mistake in the mess of all these equations?”

Richard Feynman

Reading about the lives of talented researchers, ones who have been praised by their peers and made stunning discoveries, you pretty quickly notice that they are not afraid at all of seeming or being very dumb, or very ignorant. For example, we can consider Niels Bohr, who won the Nobel Prize in Physics in 1922 for his pioneering work in quantum mechanics:

It is practically impossible to describe Niels Bohr to a person who has never worked with him. Probably his most characteristic property was the slowness of his thinking and comprehension. … In the evening, when a handful of Bohr’s students were “working” in the Paa Blegdamsvejen Institute, discussing the latest problems of the quantum theory, or playing ping-pong on the library table with coffee cups placed on it to make the game more difficult, Bohr would appear, complaining that he was very tired, and would like to “do something.” To “do something” inevitably meant to go to the movies, and the only movies Bohr liked were those called The Gun Fight at the Lazy Gee Ranch or The Lone Ranger and a Sioux Girl. But it was hard to go with Bohr to the movies. He could not follow the plot, and was constantly asking us, to the great annoyance of the rest of the audience, questions like this: “Is that the sister of that cowboy who shot the Indian who tried to steal a herd of cattle belonging to her brother-in-law?” The same slowness of reaction was apparent at scientific meetings. Many a time, a visiting young physicist (most physicists visiting Copenhagen were young) would deliver a brilliant talk about his recent calculations on some intricate problem of the quantum theory. Everybody in the audience would understand the argument quite clearly, but Bohr wouldn’t. So everybody would start to explain to Bohr the simple point he had missed, and in the resulting turmoil everybody would stop understanding anything. Finally, after a considerable period of time, Bohr would begin to understand, and it would turn out that what he understood about the problem presented by the visitor was quite different from what the visitor meant, and was correct, while the visitor’s interpretation was wrong.

George Gamow on Niels Bohr 

Great scientists were generally quite stupid, though we admit that some of them may have been stupider than others. More notably, most of them seem to have known it! 

The first thing Bohr said to me was that it would only then be profitable to work with him if I understood that he was a dilettante. The only way I knew to react to this unexpected statement was with a polite smile of disbelief. But evidently Bohr was serious. He explained how he had to approach every new question from a starting point of total ignorance. It is perhaps better to say that Bohr’s strength lay in his formidable intuition and insight rather than erudition.

Abraham Pais

Some of this is about fear. If you accept your ignorance, you will be aware of how stupid you are. Being afraid of being stupid, or seeming stupid, will lead you to make lots of mistakes. You will be afraid to look for mistakes; you will not double-check your work with the same level of care; you will be afraid that if people find out about your mistakes, they will laugh and think you are an idiot. Once you have accepted in full confidence that you, along with all other scientists, are in fact idiots, you will no longer be worried about this. You will notice your own mistakes, or others will notice them for you, and you will laugh it off. “I’m so glad someone caught this!” you will say. 

You see, one thing is, I can live with doubt and uncertainty and not knowing. I think it’s much more interesting to live not knowing than to have answers which might be wrong. I have approximate answers and possible beliefs and different degrees of certainty about different things, but I’m not absolutely sure of anything and there are many things I don’t know anything about, such as whether it means anything to ask why we’re here, and what the question might mean. I might think about it a little bit and if I can’t figure it out, then I go on to something else, but I don’t have to know an answer, I don’t feel frightened by not knowing things, by being lost in a mysterious universe without having any purpose, which is the way it really is so far as I can tell, possibly. It doesn’t frighten me.

Richard Feynman

Mistakes are inevitable! You are a dummy; you will sometimes be wrong. It is ok to be wrong. If you’re not willing to accept that sometimes you’re wrong, you will have a hard time ever being right. Be wrong with confidence.

Don’t worry too much about your intellectual gifts. Despite popular misconceptions, a lack of IQ won’t hold you back. If you are really dumb and know it, you have a leg up on the smart people who, on a cosmic scale, are still stupid, but haven’t realized it yet. 

Brains are nice to have, but many people who seem not to have great IQs have done great things. At Bell Telephone Laboratories Bill Pfann walked into my office one day with a problem in zone melting. He did not seem to me, then, to know much mathematics, to be articulate, or to have a lot of clever brains, but I had already learned brains come in many forms and flavors, and to beware of ignoring any chance I got to work with a good man. I first did a little analytical work on his equations, and soon realized what he needed was computing. I checked up on him by asking around in his department, and I found they had a low opinion of him and his idea for zone melting. But that is not the first time a person has not been appreciated locally, and I was not about to lose my chance of working with a great idea—which is what zone melting seemed to me, though not to his own department!

Richard Hamming

Stupidity can also be part of the inspiration behind the virtue of rebellion, a scientist’s ability to defy authority figures. If you’re stupid, you don’t realize when you should keep your mouth shut, so you say what you really think. Feynman again:

The last time he was there, Bohr said to his son, “Remember the name of that little fellow in the back over there? He’s the only guy who’s not afraid of me, and will say when I’ve got a crazy idea. So next time when we want to discuss ideas, we’re not going to be able to do it with these guys who say everything is yes, yes, Dr. Bohr.

Get that guy and we’ll talk with him first.” I was always dumb in that way. I never knew who I was talking to. 

Maybe more important is that accepting your stupidity helps you cultivate the virtue of being carefree. If you think you have a great mind, you will feel a lot of pressure to work on things that are “challenging” and “important”. But you will never get anything done if you stress out about this kind of thing, and more seriously, you will never have any fun.

Perhaps one of the most interesting things that I ever heard him say was when, after describing to me an experiment in which he had placed under a bell-jar some pollen from a male flower, together with an unfertilized female flower, in order to see whether, when kept at a distance but under the same jar, the one would act in any way on the other, he remarked:—”That’s a fool’s experiment. But I love fools’ experiments. I am always making them.”

E. Ray Lankester, recalling Charles Darwin

Arrogance

My goal is simple. It is a complete understanding of the universe, why it is as it is and why it exists at all.

Stephen Hawking

Arrogance is the complement of stupidity, the yang to stupidity’s yin. Being stupid is all about recognizing that you know nothing about everything, and in fact you have little chance of ever understanding much about anything. Having accepted such complete ignorance, you must then be extraordinarily arrogant to think that you could ever make an original discovery, let alone solve a problem that has baffled people for generations. But this is exactly what we aim to do. To complement their stupidity, a scientist must also be arrogant beyond all measure.

No one else knows anything either, so when it comes to figuring something out for the first time, you have as good a shot at it as anyone else does! Why not go for it, after all? 

The condition of matter I have dignified by the term Electronic, THE ELECTRONIC STATE. What do you think of that? Am I not a bold man, ignorant as I am, to coin words?

Michael Faraday

Most people have the good sense to know what is realistic and practical, and to laugh at people who think they can do the impossible. So you have to be very dumb indeed, to be arrogant enough to think that you can change the world! 

Who would not have been laughed at if he had said in 1800 that metals could be extracted from their ores by electricity or that portraits could be drawn by chemistry.

Michael Faraday

A great gap in research is between people who try things and people who sit around thinking about whether to try things. Truly, aiming low is a dead end. Aiming low is boring.

Confidence in yourself, then, is an essential property. Or, if you want to, you can call it “courage.” Shannon had courage. Who else but a man with almost infinite courage would ever think of averaging over all random codes and expect the average code would be good? He knew what he was doing was important and pursued it intensely. Courage, or confidence, is a property to develop in yourself. Look at your successes, and pay less attention to failures than you are usually advised to do in the expression, “Learn from your mistakes.” While playing chess Shannon would often advance his queen boldly into the fray and say, “I ain’t scared of nothing.”

Richard Hamming

You will not always be right. Often you will be wrong. This is why stupidity comes before arrogance, because you have to be prepared to make lots of dumb mistakes. If you are prepared to make dumb mistakes, you can act with confidence. You will put ideas out there that you think might be wrong. But sometimes you will surprise yourself.

Is it dangerous to claim that parents have no power at all (other than genetic) to shape their child’s personality, intelligence, or the way he or she behaves outside the family home? … A confession: When I first made this proposal ten years ago, I didn’t fully believe it myself. I took an extreme position, the null hypothesis of zero parental influence, for the sake of scientific clarity. Making myself an easy target, I invited the establishment — research psychologists in the academic world — to shoot me down. I didn’t think it would be all that difficult for them to do so. … The establishment’s failure to shoot me down has been nothing short of astonishing.

Judith Rich Harris for Edge

Like stupidity, arrogance is linked to the virtue of rebellion. If you think you are hot shit, you will not be afraid to go against the opinions of famous writers, ivy-league professors, public officials, or other great minds.

The idea that smashed the old orthodoxy got its start on Christmas 1910, as Wegener (the W is pronounced like a V) browsed through a friend’s new atlas. Others before him had noticed that the Atlantic coast of Brazil looked as if it might once have been tucked up against West Africa, like a couple spooning in bed. But no one had made much of it, and Wegener was hardly the logical choice to show what they had been missing. He was a lecturer at Marburg University, not merely untenured but unsalaried, and his specialties were meteorology and astronomy, not geology.

But Wegener was not timid about disciplinary boundaries, or much else. He was an Arctic explorer and a record-setting balloonist, and when his scientific mentor and future father-in-law advised him to be cautious in his theorizing, Wegener replied, “Why should we hesitate to toss the old views overboard?”

— Richard Connff for Smithsonian Magazine

You shouldn’t cultivate arrogance in a way that makes you an asshole, though some scientists have made this mistake. This virtue is not about thinking that you are better than other people. Forget about other people. It is about thinking that you have the potential to be really good — to be damn good. It is about moving with extreme confidence. You cultivate arrogance so that if someone says, “that’s very arrogant of you!” you respond, “so what?”

Laziness

Study hard what interests you the most in the most undisciplined, irreverent and original manner possible. 

Richard Feynman

Everyone knows that research requires hard work. This is true, but your hard work has to be matched by a commitment to relaxation, slacking off, and fucking around when you “should” be working — that is, laziness.

Laziness is not optional — it is essential. Great work cannot be done without it. And it must be cultivated as a virtue, because a sinful world is always trying to push back against it.

Leonardo, knowing that the intellect of that Prince was acute and discerning, was pleased to discourse at large with the Duke on the subject… and he reasoned much with him about art, and made him understand that men of lofty genius sometimes accomplish the most when they work the least, seeking out inventions with the mind, and forming those perfect ideas which the hands afterwards express and reproduce from the images already conceived in the brain.

Giorgio Vasari

Hard work needs to happen to bring an idea to fruition, but you cannot work hard all the time any more than a piston can be firing all the time, or every piston in an engine can fire at once. Pistons are always moving up and down. A piston moves up; it fires; but that action is matched by the piston moving down, and spending some time not firing. It would be foolish to complain that the piston is not firing all the time, but this is what some people do in trying to work hard all the time. They are trying to keep the piston in the down position the whole time, not recognizing that this will stop the piston from firing again, and will damage the whole engine. 

They would do better to cultivate the virtue of laziness, and go take a nap or stare at the clouds or play fetch with their dog or something. Taking a nap is just turning your brain off and then on again, which solves 90% of my computer problems.

Albert Einstein once asked a friend of mine in Princeton, “Why is it I get my best ideas in the morning while I’m shaving?” My friend answered, as I have been trying to say here, that often the mind needs the relaxation of inner controls — needs to be freed in reveries or day dreaming — for the unaccustomed ideas to emerge.

Rollo May

Mathematicians are not exactly scientists, but they certainly have one of the best claims on pure idea work. So you might expect that for mathematicians, more time spent working would lead to more results. But apparently not. G.H. Hardy, one of the great British mathematicians of the 20th century, started his mornings by reading the cricket scores (or when cricket was not in season, the Australian cricket scores). He would work only from 9 to 1, after which he would eat lunch, play tennis, or (surprise) watch a game of cricket. His collaborator John Edensor Littlewood said:

You must also acquire the art of ‘thinking vaguely,’ an elusive idea I can’t elaborate in short form. After what I have said earlier, it is inevitable that I should stress the importance of giving the subconscious every chance. There should be relaxed periods during the working day, profitably, I say, spent in walking. … On days free from research, and apart from regular holidays, I recommend four hours [of work] a day or at most five, with breaks about every hour (for walks perhaps). If you don’t have breaks you unconsciously acquire the habit of slowing down. 

John Edensor Littlewood

Henri Poincaré is perhaps the best example. He was something of a mathematician but also worked in physics and engineering, and he worked around four hours a day. Poincaré happened to have several experiences where hard work failed to crack a problem, but laziness or relaxation did the trick; for example, drinking coffee too late and messing up his sleep schedule:

For fifteen days I strove to prove that there could not be any functions like those I have since called Fuchsian functions. I was then very ignorant; every day I seated myself at my work table, stayed an hour or two, tried a great number of combinations and reached no results. One evening, contrary to my custom, I drank black coffee and could not sleep. Ideas rose in crowds; I felt them collide until pairs interlocked, so to speak, making a stable combination. By the next morning I had established the existence of a class of Fuchsian functions, those which come from the hypergeometric series; I had only to write out the results, which took but a few hours.

Henri Poincaré

Or, even more effortless, getting onto a bus:

I left Caen, where I was living, to go on a geological excursion under the auspices of the School of Mines. The incidents of the travel made me forget my mathematical work. Having reached Coutances, we entered an omnibus to go some place or other. At the moment when I put my foot on the step the idea came to me, without anything in my former thoughts seeming to have paved the way for it, that the transformations I had used to define the Fuchsian functions were identical with those of non-Euclidean geometry. I did not verify the idea; I should not have had time, as, upon taking my seat in the omnibus, I went on with a conversation already commenced, but I felt a perfect certainty. On my return to Caen, for conscience’s sake I verified the result at my leisure.

Then I turned my attention to the study of some arithmetical questions apparently without much success and without a suspicion of any connection with my preceding researches. Disgusted with my failure, I went to spend a few days at the seaside and thought of something else. One morning, while walking on the bluff, the idea came to me, with just the same characteristics of brevity, suddenness and immediate certainty, that the arithmetic transformations of indefinite ternary quadratic forms were identical with those of non-Euclidean geometry.

Henri Poincaré

(In fact there seems to be something about buses. If you are working on a problem you just can’t crack, maybe take a bus ride?)

In 1865, Kekulé himself came up with the answer. He related some years later that the vision of the benzene molecule came to him while he was riding on a bus and sunk in a reverie, half asleep. In his dream, chains of carbon atoms seemed to come alive and dance before his eyes, and then suddenly one coiled on itself like a snake. Kekulé awoke from his reverie with a start.

Isaac Asimov

Poincaré and Kekulé aren’t the only ones. For Linus Pauling, a head cold and pulpy detective novels seems to have done the trick:

In Oxford, it was April, I believe, I caught cold. I went to bed, and read detective stories for a day, and got bored, and thought why don’t I have a crack at that problem of alpha keratin.

Linus Pauling

This was one of the one of the many achievements that led to his Nobel Prize in Chemistry in 1954. So next time you think, “I shouldn’t read detective stories until I get bored, I should be working,” please reconsider.

Insight comes suddenly and without warning, but rarely when you have your nose to the grindstone. So spend some time staring out your dormitory window. If you don’t learn to be lazy, you might miss it.

Carefreeness

I lie on the beach like a crocodile and let myself be roasted by the sun. I never see a newspaper and don’t give a damn for what is called the world.

Albert Einstein, letter to Max Born

The hardest of the scientific virtues to cultivate may be the virtue of carefreeness. This is the virtue of not taking your work too seriously. If you try too hard, you get serious, you get worried, you’re not carefree anymore — you see, it’s a problem.

So I got this new attitude. Now that I am burned out and I’ll never accomplish anything, I’ve got this nice position at the university teaching classes which I rather enjoy, and just like I read the Arabian Nights for pleasure, I’m going to play with physics, whenever I want to, without worrying about any importance whatsoever.

Within a week I was in the cafeteria and some guy, fooling around, throws a plate in the air. As the plate went up in the air I saw it wobble, and I noticed the red medallion of Cornell on the plate going around. It was pretty obvious to me that the medallion went around faster than the wobbling.

I had nothing to do, so I start to figure out the motion of the rotating plate. I discover that when the angle is very slight, the medallion rotates twice as fast as the wobble rate — two to one. It came out of a complicated equation! Then I thought, “Is there some way I can see in a more fundamental way, by looking at the forces or the dynamics, why it’s two to one?”

I don’t remember how I did it, but I ultimately worked out what the motion of the mass particles is, and how all the accelerations balance to make it come out two to one.

I still remember going to Hans Bethe and saying, “Hey, Hans! I noticed something interesting. Here the plate goes around so, and the reason it’s two to one is…” and I showed him the accelerations.

He says, “Feynman, that’s pretty interesting, but what’s the importance of it? Why are you doing it?”

“Hah!” I say. “There’s no importance whatsoever. I’m just doing it for the fun of it.” His reaction didn’t discourage me; I had made up my mind I was going to enjoy physics and do whatever I liked.

I went on to work out equations of wobbles. Then I thought about how electron orbits start to move in relativity. Then there’s the Dirac Equation in electrodynamics. And then quantum electrodynamics. And before I knew it (it was a very short time) I was “playing” — working, really — with the same old problem that I loved so much, that I had stopped working on when I went to Los Alamos: my thesis-type problems; all those old-fashioned, wonderful things.

It was effortless. It was easy to play with these things. It was like uncorking a bottle: Everything flowed out effortlessly. I almost tried to resist it! There was no importance to what I was doing, but ultimately there was. The diagrams and the whole business that I got the Nobel Prize for came from that piddling around with the wobbling plate.

Richard Feynman

This is related to the scientific virtue of laziness — a carefree person will find it easier to take time off from their work, to relax, go sailing, play ping-pong, etc. But carefreeness is a higher virtue than even laziness is. Being carefree means not worrying and relaxing even when you are working very hard.

If you do not cultivate the sense of carefreeness, you will get all tangled up about not working on “important” problems. You will get all tangled up about working on the things you think you “should be” working on, instead of the things you want to be working on, the things you find fun and interesting.

If research starts to be a drag, it won’t matter how talented you are. Nothing will kill your spark faster than finding research dull. Nothing will wring you out more than working on things you hate but you think are “important”. 

This is tricky because there are many different ways you can lose your sense of carefreeness. There are a lot of things that can throw off your groove. The first is becoming attached to worldly rewards — cash, titles, fancy hats, etc.

I am happy because I want nothing from anyone. I do not care about money. Decorations, titles or distinctions mean nothing to me. I do not crave praise. The only thing that gives me pleasure, apart from my work, my violin, and my sailboat, is the appreciation of my fellow workers.

Albert Einstein

When you start seeking these rewards, or even thinking about them too much, the whole research enterprise falls apart. Sometimes this can happen overnight. 

You might say, “well surely someone has to think about these practical problems.” It’s true that some people should think about worldly things, but we don’t exactly see a shortage of that. What cannot be forced, and can only be cultivated, are free minds pursuing things that no one else thinks are interesting problems, for no good reason at all.

We must not forget that when radium was discovered no one knew that it would prove useful in hospitals. The work was one of pure science. And this is a proof that scientific work must not be considered from the point of view of the direct usefulness of it. It must be done for itself, for the beauty of science, and then there is always the chance that a scientific discovery may become like the radium a benefit for humanity.

Marie Curie

The best ideas are almost certainly going to be ones that seem insane or stupid — if they seemed like good ideas, someone would have tried them already. How can there possibly be a market for such ideas? They are left to people who are carefree enough in their spirit to pursue these dumb ideas anyways. Most great advances are preceded by announcements that they are impossible, and you need to be ready and willing to ignore that stuff:

The whole procedure [of shooting rockets into space]… presents difficulties of so fundamental a nature, that we are forced to dismiss the notion as essentially impracticable, in spite of the author’s insistent appeal to put aside prejudice and to recollect the supposed impossibility of heavier-than-air flight before it was actually accomplished.

Sir Richard van der Riet Woolley, British astronomer, reviewing P.E. Cleator’s “Rockets in Space”, Nature, March 14, 1936

Some people are ok at resisting money and fame. But people find it harder to avoid being swayed by praise. It is easy to want to impress people, and want them to like you. But if you start worrying about praise, two things will happen. First of all, you will be worrying, which will cloud your head. Second, if you are trying to get praise, you will work on problems that are popular. Popular problems are fine, but you have to know that they will be seductive. You should pay more attention to topics you like that aren’t popular. 

Focusing on unpopular problems you find fascinating is a good sign that you’re making use of your particular talents. Following praise is a sign you are being led away from your gifts! Taste is really important — follow what you find interesting.

…my work, which I’ve done for a long time, was not pursued in order to gain the praise I now enjoy, but chiefly from a craving after knowledge, which I notice resides in me more than in most other men. And therewithal, whenever I found out anything remarkable, I have thought it my duty to put down my discovery on paper, so that all ingenious people might be informed thereof.

Antonie van Leeuwenhoek, Letter of June 12, 1716

Another is worrying about being an “expert”, keeping up with the field, staying aware of the latest publications, et cetera. Staying carefree means being happy to ignore these things (if you feel like it). 

You can tell really good science because it stays carefree even when the stakes are very high:

I remember a friend of mine who worked with me, Paul Olum, a mathematician, came up to me afterwards and said, “When they make a moving picture about this, they’ll have the guy coming back from Chicago to make his report to the Princeton men about the bomb. He’ll be wearing a suit and carrying a briefcase and so on — and here you’re in dirty shirtsleeves and just telling us all about it, in spite of its being such a serious and dramatic thing.”

Richard Feynman

Staying carefree is how you keep in touch with what really interests you. It is how you practice going with your gut. It is how you make sure you are still having fun. 

No one is doing great work when they are bent over their lab bench thinking, “gee I wish I were doing something else!” Great work doesn’t come from banging your head against your keyboard a little harder. 

Alan Turing’s celebrated paper of 1935, which was to provide the foundation of modern computer theory, was originally written as a speculative exploration for mathematical logicians. The war gave him and others the occasion to translate theory into the beginnings of practice for the purpose of code-breaking, but when it appeared nobody except a handful of mathematicians even read, let alone took notice of Turing’s paper.

— Eric Hobsbawm on Alan Turing

We cannot emphasize enough that great work almost always comes from things that at the time seemed like pointless nonsense. Those scientists did it anyway, because it interested them. But to do that you will have to be ready to stand against the world, people telling you that you should be using your gifts on something more productive, that you are wasting your talents! Cultivating this carefreeness will help you ignore them.

A large part of mathematics which becomes useful developed with absolutely no desire to be useful, and in a situation where nobody could possibly know in what area it would become useful; and there were no general indications that it ever would be so. By and large it is uniformly true in mathematics that there is a time lapse between a mathematical discovery and the moment when it is useful; and that this lapse of time can be anything from 30 to 100 years, in some cases even more; and that the whole system seems to function without any direction, without any reference to usefulness, and without any desire to do things which are useful.

John von Neumann

Not every pointless idea ends up being a great discovery — most of them do not. But a feature you will see over and over again in great scientists is a complete lack of fear when it comes to pursuing ideas that seem like (or truly are) nonsense. You might have to look into 100 dumb ideas before you find one that is any good — in fact, maybe you should start right now.

I’ve noticed that my dog can correctly tell which way I’ve gone in the house, especially if I’m barefoot, by smelling my footprints. So I tried to do that: I crawled around the rug on my hands and knees, sniffing, to see if I could tell the difference between where I walked and where I didn’t, and I found it impossible. So the dog is much better than I am.

Richard Feynman

Most people find it hard to stay carefree all the time. When you choke, and start worrying about things — are you working on the right stuff, are you wasting your life, etc. — cultivating the virtue of carefreeness is the way to get back on top.

Beauty

I am among those who think that science has great beauty. A scientist in his laboratory is not only a technician: he is also a child placed before natural phenomena which impress him like a fairy tale. We should not allow it to be believed that all scientific progress can be reduced to mechanisms, machines, gearings, even though such machinery also has its beauty.

Neither do I believe that the spirit of adventure runs any risk of disappearing in our world. If I see anything vital around me, it is precisely that spirit of adventure, which seems indestructible and is akin to curiosity.

Marie Curie

The fifth virtue that a scientist must cultivate is an appreciation for beauty. There are practical reasons to do science, but in the moment, great research is done just to do something because it’s beautiful and exemplifies enjoying that beauty.  

This eye for beauty is not optional! It is, like all the scientific virtues, essential for doing any kind of original research.

The scientist does not study nature because it is useful; he studies it because it pleases him, and it pleases him because it is beautiful. Were nature not beautiful, it would not be worth knowing, life would not be worth living.

Henri Poincaré

Every scientist is limited by their appreciation for beauty. If you have developed an eye for it, your work will benefit. Without a sense for it, your work will suffer. It does not matter if your taste is for poetry, pinwheels, or cricket plays. You can have an obsession with video game music, or be an ameteur baker. You must be able to see the beauty in something — it is practice for seeing the beauty and the harmony of nature. The more kinds of beauty you learn to appreciate, the better your work will become.

The mathematician’s patterns, like the painter’s or the poet’s must be beautiful; the ideas, like the colours or the words must fit together in a harmonious way. Beauty is the first test: there is no permanent place in this world for ugly mathematics. 

G. H. Hardy

To many people, a scientist will seem obsessive. This is true, but obsession is not by itself a virtue. The obsession you see in many researchers comes from their sense of beauty — they know what it should look like. They have an intense need to get it right. They cannot let it alone when they know it is wrong — it keeps calling them back. Only when it is right will it be beautiful.

Copernicus’ aesthetic objections to [equants] provided one essential motive for his rejection of the Ptolemaic system.

Thomas Kuhn, The Copernican Revolution

This is why we cultivate an appreciation for aesthetics, rather than cultivating obsession itself. Pure obsession will lead you to pursue any project anywhere, even if it leads you up a tree. Cultivating aesthetics, you will only follow projects if they lead you up the trunks of particularly beautiful trees.

This builds on itself. Building an aesthetic sense leads you to become a better researcher. Practicing this sense in your work becomes another way to develop this virtue. Having developed the virtue, you can now appreciate the beauty in more things. This develops your aesthetic sense further, your work improves, the virtue reaches a higher stage of refinement, etc.

I have a friend who’s an artist, and he sometimes takes a view which I don’t agree with. He’ll hold up a flower and say, “Look how beautiful it is,” and I’ll agree. But then he’ll say, “I, as an artist, can see how beautiful a flower is. But you, as a scientist, take it all apart and it becomes dull.” I think he’s kind of nutty. … There are all kinds of interesting questions that come from a knowledge of science, which only adds to the excitement and mystery and awe of a flower. It only adds. I don’t understand how it subtracts.

Richard Feynman

Part of what is called beauty could simply be called fun. If you don’t know how to have fun, you will not be able to appreciate the beauty around you — you will not have a good time.

McClintock was motivated by the intrinsic rewards that she experienced from the work itself. She was rewarded every day by the joy she felt in the endeavor. She loved posing questions, finding answers, solving problems. She loved working in her garden and in her laboratory. She recalled later, “I was doing what I wanted to do, and there was absolutely no thought of a career. I was just having a marvelous time.” 

Upon hearing that she had been named for the Nobel Prize, McClintock told reporters, “The prize is such an extraordinary honor. It might seem unfair, however, to reward a person for having so much pleasure, over the years, asking the maize to solve specific problems and then watching its response.” When asked if she was bitter about the lateness of the recognition, she said simply, “If you know you’re right, you don’t care. You know that sooner or later, it will come out in the wash.”

— Abigail Lipson on Barbara McClintock

Given all this, perhaps it’s not surprising that many scientists are also talented artists and musicians.

If I was not a physicist, I would probably be a musician. I often think in music. I live my daydreams in music. I see my life in terms of music. … I cannot tell if I would have done any creative work of importance in music, but I do know that I get most joy in life out of my violin.

Albert Einstein

Just how good a violinist was Einstein? One time, a confused music critic in Berlin thought Einstein was a famous violinist rather than a famous physicist, and said, “Einstein’s playing is excellent, but he does not deserve world fame; there are many others just as good.”

Leonardo da Vinci is famous for his painting and drawing, of course, but what you may not know is that he was also something like the 15th century equivalent of a heavy metal virtuoso:

In the year 1494, Leonardo was summoned to Milan in great repute to the Duke, who took much delight in the sound of the lyre, to the end that he might play it: and Leonardo took with him that instrument which he had made with his own hands, in great part of silver, in the form of a horse’s skull—a thing bizarre and new—in order that the harmony might be of greater volume and more sonorous in tone; with which he surpassed all the musicians who had come together there to play. Besides this, he was the best improviser in verse of his day.

Giorgio Vasari

Richard Feynman (Nobel Prize in Physics, 1965) was famous for playing bongos, and briefly played the frigideira in a Brazilian samba band. He also made some progress as a portrait artist, to the point where he sold several pieces and even had a small exhibit. 

Barbara McClintock (Nobel Prize in Physiology or Medicine, 1983) played tenor banjo in a jazz combo for years, but in the end she had to give it up because it kept her up too late at night. 

Santiago Ramón y Cajal (Nobel Prize in Physiology or Medicine, 1906) ranks up there almost with Da Vinci in terms of the incredible breadth of his artistic pursuits:

Santiago Ramón y Cajal (1852–1934) is one of the more fascinating personalities in science. Above all he was the most important neuroanatomist since Andreas Vesalius, the Renaissance founder of modern biology. However, Cajal was also a thoughtful and inspired teacher, he made several lasting contributions to Spanish literature (his autobiography, a popular book of aphorisms, and reflections on old age), and he wrote one of the early books on the theory and practice of color photography. Furthermore, he was an exceptional artist, perhaps the best ever to draw the circuits of the brain, which he could never photograph to his satisfaction.

Larry W. Swanson, foreword to Cajal’s book Advice for a Young Investigator

We can add to this list that Cajal also wrote a number of science-fiction stories that were considered too scandalous for publication. Five were eventually published under the pseudonym “Dr. Bacteria” (yes, really), but the rest were considered too offensive to be published even at this remove, and they have since been lost.

This was also true for many of the old masters. James Clerk Maxwell was fascinated by color, and helped invent color photography. Robert Hooke was apprenticed to a painter as a young man, and proved pretty good at it. He did all his own illustrations for his book Micrographia, which to this day remain impressive. Sir Isaac Newton also seemed to have quite the knack for illustration:

Mr. Clark, aforementioned now apothecary, & surgeon in Grantham, tells me, that he himself likewise lodg’d, whilst a youth, in that same garret in the old house where Sr. Isaac had done. he says, the walls, & ceelings were full of drawings, which he had made with charcole. there were birds, beasts, men, ships, plants, mathematical figures, circles, & triangles. that the drawings were very well done. & scarce a board in the partitions about the room, without Isaac Newton cut upon it. … Sr Isaac when a lad here at School, was not only expert at his mechanical tools, but equally so with his pen. for he busyed himself very much in drawing, which he took from his own inclination; & as in every thing else, improv’d it by a careful observation of nature.

— William Stukeley on Isaac Newton

This is only an incomplete list — not every talented scientist is also a musician or artist. But a scientist’s success depends on the cultivation of their aesthetic sense, and this sense of beauty is essential to every researcher.

I am no poet, but if you think for yourselves, as I proceed, the facts will form a poem in your minds. 

Michael Faraday

Rebellion

… a reaction I learned from my father: Have no respect whatsoever for authority; forget who said it and instead look what he starts with, where he ends up, and ask yourself, “Is it reasonable?” 

Richard Feynman

To do research you must be free. Free to question. Free to doubt. Free to come up with new perspectives and new approaches. Free to challenge the old ways of doing things, or worse, ignore them. Free to try to solve problems where everyone thinks they know the answer. Free to not spend all your time hunched over your workbench and let your mind wander. Free to tinker with pointless ideas. Free to turn over rocks and look at the bugs underneath. 

The world must be free and open as well. You need to be free to meet and discuss things with anyone you want. You must have free access to books, libraries, journals, the internet. You must be free to try things and build things for yourself. 

But not everyone shares these values. And, because we are social creatures and we were brought up in societies that are less than totally free, we carry around an inner authoritarian in our heads. We cultivate the virtue of rebellion to free us from inner and outer attempts to suppress our freedom of thought and expression. 

There must be no barriers to freedom of inquiry … There is no place for dogma in science. The scientist is free, and must be free to ask any question, to doubt any assertion, to seek for any evidence, to correct any errors. Our political life is also predicated on openness. We know that the only way to avoid error is to detect it and that the only way to detect it is to be free to inquire. And we know that as long as men are free to ask what they must, free to say what they think, free to think what they will, freedom can never be lost, and science can never regress.

J. Robert Oppenheimer

Spitting in the eye of authority isn’t easy — it doesn’t come naturally to most people. So rebellion must be cultivated in small ways every day. You may not have to actively rebel very often, but the material for raising hell should always be kept in readiness.

To do science you have to be ready to pick at the idea that something might be wrong. The most important new ideas are going to be most at odds with what we believe right now. Having a mind free enough to think thoughts that have never been thought before is absolutely necessary.

The vibe of rebellion is, “the prevailing order is wrong — but some other order might be right.” Things could be fundamentally different than they are now; everything you take for granted could be ungranted. 

It’s not that this is true 100% of the time — sometimes the usual way of thinking is right — just that it won’t be obvious unless you’re questioning what you “know”. To some degree, rebellion is basically just acknowledging that the status quo can lead you astray.

Not everyone likes the idea of turning the current order upside down, so you may have to fight for it, or even for the right to speculate about it. But it’s important because making the world a better place is worth it. 

Research depends on cultivating the skill of looking at something and thinking — gee, this could be better. This instrument could be better. This theory could be better. Our understanding of this question could be better. This leads to the cultivation of the virtue of rebellion, where you look at how things are today, and think, you know what, they could be better.

I won’t stop at being Robin Hood. I feel more like a revolutionary because the final goal is not only to download all the articles and books and give open access to them, but to change legislation in such a way that free distribution of research papers will not face any legal obstacles.

Alexandra Elbakyan

Rebellion is one of the highest scientific virtues. It is supported by stupidity — because you have to be pretty dumb to bet against the status quo and think you can win. It is supported by arrogance — in that you must be pretty arrogant to think you know better than the experts. It is supported by aesthetics — because seeing the possibility for a more beautiful experiment, a more beautiful theory, a more beautiful world is needed to inspire your rebellion. It is supported by carefreeness — not worrying about whether you win or lose makes the struggle against authority that much easier. Whenever possible, rebellion should be fun.

Rebellion is also egalitarian — it means focusing on people’s arguments, not their credentials. If their arguments are solid, then it doesn’t matter if they are, in fact, a soccer mom. If their arguments are so full of holes you can see them from a mile away, then it doesn’t matter where their PhD is from, or what university gave them tenure.

If it disagrees with experiment it is wrong. In that simple statement is the key to science. It does not make any difference how beautiful your guess is. It does not make any difference how smart you are, who made the guess, or what his name is – if it disagrees with experiment it is wrong. That is all there is to it.

Richard Feynman

The virtue of rebellion means cultivating in yourself the ability to stand up to anyone on the planet, to question them as an equal, and to not take anything they say on authority alone. But rebellion is not about getting in fights for no reason — be strategic.

John Tukey almost always dressed very casually. He would go into an important office and it would take a long time before the other fellow realized that this is a first-class man and he had better listen. For a long time John has had to overcome this kind of hostility. It’s wasted effort! I didn’t say you should conform; I said “The appearance of conforming gets you a long way.” If you choose to assert your ego in any number of ways, “I am going to do it my way,” you pay a small steady price throughout the whole of your professional career. And this, over a whole lifetime, adds up to an enormous amount of needless trouble.

Richard Hamming 

This virtue extends outside of the research world, because nature does not stop at the laboratory door! Practicing rebellion has to extend to every part of your life. 

It’s easy to parrot experts. Even just saying “I don’t understand” is an act of rebellion. If you want to be free to be confused, to doubt, to ask dumb questions, you need to be prepared to be a rebel.

Every valuable human being must be a radical and a rebel, for what he must aim at is to make things better than they are.

Niels Bohr

You need to cultivate rebellion because people won’t always understand the value of that weird thing you are doing. You have to be ready to do it anyways. One reviewer of Charles Darwin’s book On The Origin of Species suggested that “Mr. D” re-write the book to focus on his observations of pigeons. “Every body is interested in pigeons,” they said. “The book would be reviewed in every journal in the kingdom, & would soon be on every table. … The book on pigeons would be at any rate a delightful commencement.” Barbara McClintock’s parents were against her research because they didn’t think there was any value in genetics!

The world in general disapproves of creativity, and to be creative in public is particularly bad. Even to speculate in public is rather worrisome.

Isaac Asimov

Similarly, if you have cultivated this virtue, you will also be ok with other people doing research that you don’t understand. Anyone doing really first-rate work must be doing something you don’t get — because if you understood it, it couldn’t possibly be all that original. So when you see a project that makes you scratch your head, think — it might be nothing, but let’s see where it goes, it could be a big deal.

In addition, exercising your rebellious thinking on social issues is good practice for rebellious thinking on scientific issues.

Unthinking respect for authority is the greatest enemy of truth.

Albert Einstein

Many people are open-minded. But some people have a hard time imagining society changing in any way, even for the better. It makes some people uncomfortable. So you need to be ready to try anyways, even in the face of this discouragement. 

I used to cut vegetables in the kitchen. String beans had to be cut into one-inch pieces. The way you were supposed to do it was: You hold two beans in one hand, the knife in the other, and you press the knife against the beans and your thumb, almost cutting yourself. It was a slow process. So I put my mind to it, and I got a pretty good idea. I sat down at the wooden table outside the kitchen, put a bowl in my lap, and stuck a very sharp knife into the table at a forty-five-degree angle away from me. Then I put a pile of the string beans on each side, and I’d pick out a bean, one in each hand, and bring it towards me with enough speed that it would slice, and the pieces would slide into the bowl that was in my lap.

So I’m slicing beans one after the other — chig, chig, chig, chig, chig — and everybody’s giving me the beans, and I’m going like sixty when the boss comes by and says, “What are you doing?”

I say, “Look at the way I have of cutting beans!” — and just at that moment I put a finger through instead of a bean. Blood came out and went on the beans, and there was a big excitement: “Look at how many beans you spoiled! What a stupid way to do things!” and so on. So I was never able to make any improvement, which would have been easy — with a guard, or something — but no, there was no chance for improvement.

Richard Feynman

This puts you at odds with authority. Kings, princes, and network executives do not want revolutionary new ideas. They generally like the current system, because they are used to it, and this system has given them positions of respect and power. They are going to do what they can to encourage people to accept how things are, or at least accept that for any problems that do exist, qualified people are taking care of it.

The scientist has a lot of experience with ignorance and doubt and uncertainty, and this experience is of very great importance, I think. When a scientist doesn’t know the answer to a problem, he is ignorant. When he has a hunch as to what the result is, he is uncertain. And when he is pretty darn sure of what the result is going to be, he is still in some doubt. We have found it of paramount importance that in order to progress we must recognize our ignorance and leave room for doubt. Scientific knowledge is a body of statements of varying degrees of certainty – some most unsure, some nearly sure, but none absolutely certain. Now, we scientists are used to this, and we take it for granted that it is perfectly consistent to be unsure, that it is possible to live and not know. But I don’t know whether everyone realizes this is true. Our freedom to doubt was born out of a struggle against authority in the early days of science. It was a very deep and strong struggle: permit us to question – to doubt – to not be sure. I think that it is important that we do not forget this struggle and thus perhaps lose what we have gained.

Richard Feynman

It is not enough to simply question the wisdom of experts, or to not listen to authority yourself. You have to cultivate ACTIVE REBELLION. Authority will constantly be telling you that things are understood, that they cannot be improved, that you cannot run in the halls. You need to actively undermine this — by finding ways that the world is not understood, by trying to improve things, by organizing go-kart races during lunch period. 

Authority will tell you to wait until the time is right, or wait for other people who are more qualified to have a go at it. But if you wait you will never get anywhere. You need to try small things right away, to try and fail and learn, to experiment and have a go at it.

Science as subversion has a long history. … Davis and Sakharov belong to an old tradition in science that goes all the way back to the rebels Benjamin Franklin and Joseph Priestley in the eighteenth century, to Galileo and Giordano Bruno in the seventeenth and sixteenth. If science ceases to be a rebellion against authority, then it does not deserve the talents of our brightest children. … We should try to introduce our children to science today as a rebellion against poverty and ugliness and militarism and economic injustice.

Freeman Dyson

This even puts you at odds with other scientists. Like other entrenched authorities, any change to the status quo threatens the position of scientists who have come before you. In fact it’s somewhat worse with other scientists, because the more famous they are, the bigger a target there is on their back. A good way to do great work is to tear down famous work by the previous generation, and you can imagine why the previous generation has a hard time feeling excited about this idea.

When an old and distinguished person speaks to you, listen to him carefully and with respect — but do not believe him. Never put your trust into anything but your own intellect. Your elder, no matter whether he has gray hair or has lost his hair, no matter whether he is a Nobel laureate — may be wrong.

Linus Pauling

Ideas can also have authority. A good idea in science tends to stick around until you barely notice it anymore. It’s not just that you see them as necessary, it’s that they start to seem like part of the background, a totally reasonable assumption. You take them for granted. But questioning old ideas is even more important than questioning old people, and a high exercise of rebellion is trying to tear down old ways of thinking, ways of thinking so old that you didn’t even realize you thought that way.

Concepts that have proven useful in ordering things easily achieve such authority over us that we forget their earthly origins and accept them as unalterable givens. Thus they might come to be stamped as “necessities of thought,” “a priori givens,” etc. The path of scientific progress is often made impassable for a long time by such errors. Therefore it is by no means an idle game if we become practiced in analysing long-held commonplace concepts and showing the circumstances on which their justification and usefulness depend, and how they have grown up, individually, out of the givens of experience. Thus their excessive authority will be broken. They will be removed if they cannot be properly legitimated, corrected if their correlation with given things be far too superfluous, or replaced if a new system can be established that we prefer for whatever reason.

Albert Einstein, Obituary for physicist and philosopher Ernst Mach (Nachruf auf Ernst Mach)

This is the great curse of success in science — it turns you into an authority figure. All of a sudden you, the little fringe weirdo that you are, are regarded as an expert. People start taking you seriously. People stop questioning your work, and start defending it! What’s worse, they defend your work on its reputation, rather than on how good it is. 

To punish me for my contempt of authority, Fate has made me an authority myself.

Albert Einstein

If you are so unlucky as to live to see this tragedy, you should try to see your status as an authority figure as a big joke. When it comes to these things, you need to have a sense of…

Humor

Good design is often slightly funny. … Godel’s incompleteness theorem seems like a practical joke.

Paul Graham

The final and — perhaps most important — virtue is humor. We see over and over again that individual scientists had wonderful, strange senses of humor.

Einstein in real life was not only a great politician and a great philosopher. He was also a great observer of the human comedy, with a robust sense of humor. … Lindemann took him to the school to meet one of the boys who was a family friend. The boy was living in Second Chamber, in an ancient building where the walls are ornamented with marble memorials to boys who occupied the rooms in past centuries. Einstein and Lindemann wandered by mistake into the adjoining First Chamber, which had been converted from a living room to a bathroom. In First Chamber, the marble memorials were preserved, but underneath them on the walls were hooks where boys had hung their smelly football clothes. Einstein surveyed the scene for a while in silence, and then said: “Now I understand: the spirits of the departed pass over into the trousers of the living.”

Freeman Dyson, “Einstein as a Jew and a Philosopher”, The New York Review of Books

A good sense of humor comes in many forms — wordplay, slapstick, poking fun at annoying colleagues…

It is said that the Prior of that place kept pressing Leonardo, in a most importunate manner, to finish the work … he complained of it to the Duke, and that so warmly, that he was constrained to send for Leonardo … [Leonardo explained] that two heads were still wanting for him to paint; that of Christ, which he did not wish to seek on earth; … Next, there was wanting that of Judas, which was also troubling him, not thinking himself capable of imagining features that should represent the countenance of him who, after so many benefits received, had a mind so cruel as to resolve to betray his Lord, the Creator of the world. However, he would seek out a model for the latter; but if in the end he could not find a better, he should not want that of the importunate and tactless Prior. This thing moved the Duke wondrously to laughter.

Giorgio Vasari

In On the Origin of Species, Darwin wrote that bumblebees are the only species that pollinates red clover. He discovered in 1862 that honeybees also pollinate red clover. Prompted by this discovery, he wrote to his friend John Lubbock, saying, “I hate myself, I hate clover, and I hate bees.” In his correspondence to W. D. Fox in October of 1852, he writes of his work on Cirripedia, “of which creatures I am wonderfully tired: I hate a Barnacle as no man ever did before, not even a Sailor in a slow-sailing ship.” Another time he wrote, “I am very poorly today and very stupid and hate everybody and everything.”

Many things conspire to make humor so important. One aspect of humor is noticing a pattern that almost everyone has missed, but which is undeniable once it’s been pointed out. Really good research does the same thing — you notice something that has always been there, and which is apparent in retrospect, but that no one has ever noticed before.

Once the cross-connection is made, it becomes obvious. Thomas H. Huxley is supposed to have exclaimed after reading On the Origin of Species, “How stupid of me not to have thought of this.”

Isaac Asimov

Making these little connections is an essential part of humor. If you train yourself to see and appreciate these little jokes in your everyday life, with friends, at the movies, etc., you will get better at seeing them in your work.

In spite of twenty-five years in Southern California, [Aldous Huxley] remains an English gentleman. The scientist’s habit of examining everything from every side and of turning everything upside down and inside out is also characteristic of Aldous. I remember him leafing through a copy of Transition, reading a poem in it, looking again at the title of the magazine, reflecting for a moment, then saying, “Backwards it spells NO IT ISN(T) ART.”

Igor Stravinsky, Dialogues

David Ogilvy wasn’t a scientist, but he was right when he said, “The best ideas come as jokes. Make your thinking as funny as possible.”

One of economist Tyler Cowen’s favorite questions to bug people with is, “‘What is it you do to train that is comparable to a pianist practicing scales?’ If you don’t know the answer to that one, maybe you are doing something wrong or not doing enough.” For scientists, the perfect practice is telling jokes. 

László Polgár believed that geniuses are made, not born, and set out to prove it. He kept his daughters on a strict educational schedule that included studying chess for up to six hours a day. There was also a twenty-minute period dedicated to telling jokes.

— Louisa Thomas on László Polgár

Having a sense of humor also helps keep things in perspective.

When I gave a lecture in Japan, I was asked not to mention the possible re-collapse of the universe, because it might affect the stock market. However, I can re-assure anyone who is nervous about their investments that it is a bit early to sell: even if the universe does come to an end, it won’t be for at least twenty billion years. By that time, maybe the GATT trade agreement will have come into effect.

Stephen Hawking

Humor keeps you from taking yourself too seriously.

The downside of my celebrity is that I cannot go anywhere in the world without being recognized. It is not enough for me to wear dark sunglasses and a wig. The wheelchair gives me away.

Stephen Hawking

Life is hard — sometimes the world is very dark. Research can be challenging. Pursuing an interest that few people understand, that sets you up against the authorities of your day, is often isolating. Scientists may discover things they would rather not have known. A sense of humor lessens the burden.

Schopenhauer’s saying, that “a man can do as he will, but not will as he will,” has been an inspiration to me since my youth up, and a continual consolation and unfailing well-spring of patience in the face of the hardships of life, my own and others’. This feeling mercifully mitigates the sense of responsibility which so easily becomes paralyzing, and it prevents us from taking ourselves and other people too seriously; it conduces to a view of life in which humor, above all, has its due place.

Albert Einstein

Another reason to cultivate humor is that nature is really weird. It will always be stranger and more amusing than you expect. The only way to keep up is to try to think in jokes. If you have a good sense of humor, you will end up closer to the truth. “Wouldn’t it be absurd if X were true?” you think, only to discover the next day that X is indeed true. 

The most exciting phrase to hear in science, the one that heralds new discoveries, is not “Eureka” but “That’s funny…”

Isaac Asimov

 Finally, science is very social. If you have a good sense of humor, people will like you. You will get along with them better; you will have more fun; probably you will do better work together! Humor is worth cultivating for this reason too. 

Humor is generative. It attracts unusual people and ideas, the sort that wouldn’t otherwise end up in the same place together.

A deep sense of humor and an unusual ability for telling stories and jokes endeared Johnny even to casual acquaintances.

— Eugene Wigner, in “John von Neumann (1903 – 1957)”

Science is too important to be taken seriously. In the end, if you cannot have some fun out of your research, if you cannot see in some way how ridiculous the whole thing is — then what’s the point? 

When I was younger I was anti-culture, but my father had some good books around. One was a book with the old Greek play The Frogs in it, and I glanced at it one time and I saw in there that a frog talks. It was written as “brek, kek, kek.” I thought, “No frog ever made a sound like that; that’s a crazy way to describe it!” so I tried it, and after practicing it awhile, I realized that it’s very accurately what a frog says.

So my chance glance into a book by Aristophanes turned out to be useful, later on: I could make a good frog noise at the students’ ceremony for the Nobel-Prize-winners! And jumping backwards fit right in, too. So I liked that part of it; that ceremony went well.

Richard Feynman

Like a Lemon to a Lime, a Lime to a Lemon


We recently wrote a post
about Maciej Cegłowski’s essay Scott And Scurvy, a fascinating account of how the cure for scurvy was discovered, lost, and then by incredible chance, discovered again. At the time we said that this essay is one of the most interesting things we’ve ever read, and that we hoped to write more about it in the future. It was, we do, and here we go.

In the other post, we talked about what the history of scurvy can teach us about contradictory evidence — stuff that appears to disprove a theory, even though it doesn’t always. In this post, we want to talk about something different: the power of concepts.

First we’re gonna show you how bad it can be if you don’t have concepts you need. Then we’re going to show you how bad it can be if you DO have concepts you DON’T need.

Diseases of Deficiency

As Cegłowski puts it:

There are several aspects of this ‘second coming’ of scurvy in the late 19th century that I find particularly striking … [one was] how difficult it was to correctly interpret the evidence without the concept of ‘vitamin’. Now that we understand scurvy as a deficiency disease, we can explain away the anomalous results that seem to contradict that theory (the failure of lime juice on polar expeditions, for example). But the evidence on its own did not point clearly at any solution. It was not clear which results were the anomalous ones that needed explaining away. The ptomaine theory made correct predictions (fresh meat will prevent scurvy) even though it was completely wrong.

We’re not quite sure if he’s right about the concept of “vitamin” — even James Lind seems to have thought the cure was something in certain foods, maybe the fact that they were so tart and acidic. More critical might be the problem of focusing on the noticeable aspect of citrus (they are very tart) and missing the hidden reason it actually cures scurvy (high in vitamin C). Not sure what advice we could give there except “don’t mistake flash for substance”, but that’s easier said than done.

But we do wonder about the concept of a deficiency disease in the first place. Even James Lind thought that scurvy was actually caused by damp air, and vegetable acids were just a way to fight back. Vegetable acids were thought to be cures, not essential nutrients. They were “antiscorbutic” like “antibiotic”. The concept of a deficiency disease doesn’t seem to have existed before the 1880s and got almost no mention until 1900, at least not under that name:

Without this concept, it does seem like doctors of the 19th century were missing an important tool in their mental toolbox for fighting disease. 

This reminds us of other problems in global medicine — maybe we should introduce the idea of a “contamination disease”. People are already familiar with this concept to a point — lead poisoning, arsenic poisoning, etc. — but people don’t look at a disease and think, maybe it’s from a contaminant. In fact, they often look at the symptoms of exposure to contaminants and think, that’s an (infectious) disease.

A good example is so-called Minamata disease. In 1956, in the city of Minamata, Japan, a pair of sisters presented with a set of disturbing symptoms, including convulsions. Soon the neighbors were showing signs as well. Doctors diagnosed an “epidemic of an unknown disease of the central nervous system”, which they called “Minamata disease”. They assumed it was contagious and took the necessary precautions. 

But soon they started hearing about mysterious cases of cats and birds showing similar symptoms, having convulsions or falling from the sky. Eventually they figured out “Minamata disease” was not contagious at all — the disease was methylmercury poisoning, the result of mercury compounds a local Chisso chemical factory was leaking into the harbor.

You might say, “Well it was not a disease at all; they were poisoned. If SMTM are right, then obesity isn’t a disease either; everyone has just been low-grade poisoned all at once.” We think this highlights the need for a deeper discussion about our categories!

“Disease” really does come from just “dis” “ease”. If you’re a doctor and someone comes to you, and they are not at ease, they are diseased, and that’s what you should care about. The disease might ultimately be bacterial, or viral, or an allergy, or a parasite, or the result of a deficiency, or the result of exposure to a harmful contaminant or poison, but it’s still a disease. For more discussion of this particular point, see here, also coincidentally about obesity, we didn’t stack the deck on this one it’s from 2010.

(If we were being really strict, we would say that obesity is a symptom, because conditions like Cushing’s Syndrome and drugs like Haldol can cause it too. If one or more contaminants also cause obesity, then the result of that exposure is a contamination disease, with obesity as a symptom. For more discussion of THIS particular point, see here.)

Lemon Mold Lime Mold

One of the weirdest things Cegłowski describes is how back in the day, people used the words “lemon” and “lime” interchangeably to describe any citrus fruit, which they thought of as a single category:

The scheduled allowance for the sailors in the Navy was fixed at I oz.lemon juice with I + oz. sugar, served daily after 2 weeks at sea, the lemon juice being often called ‘lime juice’ and our sailors ‘lime juicers’. The consequences of this new regulation were startling and by the beginning of the nineteenth century scurvy may be said to have vanished from the British navy. In 1780, the admissions of scurvy cases to the Naval Hospital at Haslar were 1457; in the years from 1806 to 1810, they were two. 

(As we’ll see, the confusion between lemons and limes would have serious reprecussions.)

This ended up making a huge difference in the tale of the tragedy of scurvy cures:

When the Admiralty began to replace lemon juice with an ineffective substitute in 1860, it took a long time for anyone to notice. In that year, naval authorities switched procurement from Mediterranean lemons to West Indian limes. The motives for this were mainly colonial – it was better to buy from British plantations than to continue importing lemons from Europe. Confusion in naming didn’t help matters. Both “lemon” and “lime” were in use as a collective term for citrus, and though European lemons and sour limes are quite different fruits, their Latin names (citrus medica, var. limonica and citrus medica, var. acida) suggested that they were as closely related as green and red apples. Moreover, as there was a widespread belief that the antiscorbutic properties of lemons were due to their acidity, it made sense that the more acidic Caribbean limes would be even better at fighting the disease. 

In this, the Navy was deceived. Tests on animals would later show that fresh lime juice has a quarter of the scurvy-fighting power of fresh lemon juice. And the lime juice being served to sailors was not fresh, but had spent long periods of time in settling tanks open to the air, and had been pumped through copper tubing. A 1918 animal experiment using representative samples of lime juice from the navy and merchant marine showed that the ‘preventative’ often lacked any antiscorbutic power at all.

It’s worth focusing on one part of this passage in particular: “Both ‘lemon’ and ‘lime’ were in use as a collective term for citrus.” This seems to be the case. As far as we can tell, the word “citrus” wasn’t really used prior to 1880. It was probably introduced as a scientific term for the genus before slowly working its way into common usage. Before then, “lemon” dominated the conversation, and “lime” dominated ten times over:

Though note that many uses of “lime” probably refer to things like quicklime. 

Maybe it’s not surprising that it took the language a while to sort itself out, but it still seems surprising that your great-great-grandfather didn’t think to distinguish between two fruits that you can tell apart at a glance. Even so, we think there are a couple of reasons to be sympathetic.

The name stuff is confusing, but swapping out one citrus fruit for another seems understandable, even if it ended up being misguided. To Europeans at the time, the thing that stood out about limes AND lemons was how tart they were, so it’s not surprising that they thought that the incredible tartness of these fruits was critical to the role they played in treating scurvy. But sourness in citrus fruits generally comes from citric acid, not vitamin C / ascorbic acid (incidentally, this is ascorbic as in “antiscorbutic”). Unfortunately, they had no way of knowing that. 

The second reason to be sympathetic is this: People mixed up limes and lemons in the 1800s. You may laugh but actually you are mixing up citrus right now.

The lemon is a single species of fruit, Citrus limon. It’s a specific species of tree that gives a specific yellow fruit that is high in citric acid and high in vitamin C. If you go to the store and buy a lemon, you know what you’re getting.

(Well, mostly. The Wikipedia page for lemons has a section called “other citrus called ‘lemons’”, which lists six other citrus fruits that are also called lemons, like the rough lemon and the Meyer lemon. But besides this, a lemon is a lemon.)

There’s also this kind of lemon, but the British Admiralty didn’t have access to these back in the age of sail.

In comparison, the Wikipedia article on limes says,

There are several species of citrus trees whose fruits are called limes, including the Key lime (Citrus aurantiifolia), Persian lime, Makrut lime, and desert lime. … Plants with fruit called “limes” have diverse genetic origins; limes do not form a monophyletic group.

The very first section of the article is called, “plants known as ‘lime’”, which gives you a sense of how vague the name “lime” really is. The list they give includes the Persian lime, the Rangpur lime, the Philippine lime, the Makrut Lime, the Key Lime, four different Australian limes, and several things called “lime” that are not even citrus fruits, including the Spanish lime and two different plants called the wild lime. They also say: 

The difficulty in identifying exactly which species of fruit are called lime in different parts of the English-speaking world (and the same problem applies to synonyms in other European languages) is increased by the botanical complexity of the citrus genus itself, to which the majority of limes belong. Species of this genus hybridise readily, and it is only recently that genetic studies have started to shed light on the structure of the genus. The majority of cultivated species are in reality hybrids, produced from the citron (Citrus medica), the mandarin orange (Citrus reticulata), the pomelo (Citrus maxima) and in particular with many lime varieties, the micrantha (Citrus hystrix var. micrantha).

This means there is not even a straight answer to a question like “how much vitamin C is in a lime?” — there are at least a dozen different fruits that are commonly called “limes”, they all contain different amounts of vitamin C, and many of them are not even related to each other.

On those remote pages it is written that limes are divided into (a) limes that belong to the Emperor, (b) embalmed limes, (c) limes that are trained, (d) suckling limes, (e) mermaid limes, (f) fabulous limes, (g) stray limes, (h) limes included in the present classification, (i) limes that tremble as if they were mad, (j) innumerable limes, (k) limes drawn with a very fine camel’s hair brush, (l) other limes, (m) limes that have just broken the flower vase, (n) limes which, from a distance, resemble flies.

The British Admiralty seems to have switched from lemons grown in Sicily to West Indian limes. You probably know these as Key limes, and in case the nomenclature isn’t complicated enough, they’re also called bartender’s limes, Omani limes, or Mexican limes. We’ll stick with “Key lime” because that’s probably the name you know because it makes me think of pie. Mmmm, pie

The kind of limes you buy at the store, Persian limes, are a cross between Key limes and lemons. We can’t find any actual tests of the amount of vitamin C in Key limes, so we think all the published estimates of the amount of vitamin C in limes are probably from Persian limes.

We generally see numbers of about 50 mg/100 g vitamin C for lemons and about 30 mg/100 g for limes, presumably Persian limes. Since Persian limes are a cross between lemons and Key limes, Key limes probably have less than 30 mg/100 g vitamin C. Genetics isn’t this simple, but if we were to assume that Persian limes are the average of their forebears, then Key limes would contain about 10 mg/100 g vitamin C, less than a tomato. You need about 10 mg of vitamin C per day to keep from getting scurvy, so already we can see why this might be a problem.

Cooking reduces the vitamin C content of vegetables by about 40% (though of course this varies widely with specific conditions), so the 50 mg or so in a lemon would become about 30 mg after boiling, but the 30 mg in a lime would become about 18 mg after boiling. Lemon juice would be as good of an antiscorbutic after boiling as Persian lime juice would be fresh, and Key limes seem like they would have less vitamin C than either, boiled or not.

Persian limes also turn yellow as they ripen — you only think of them as green because farmers pick them and send them to the grocery store before they change colors. And of course, lemons are green in their early stages of growth. So like, so much for the “limes are green and lemons are yellow” thing.

Lovely fresh limes. Yes you read that right.

All these issues pale in comparison to the fact that citrus taxonomy is insane. Not only are limes not limes, it seems like nothing is really anything, or maybe anything is everything.

You walk into a supermarket and you think you recognize a bunch of Platonic fruits — oranges, clementines, lemons, limes, grapefruits, and so on. But when you do a Google image search for “citrus genetics”, you get diagrams like:

And this diagram:

Apparently orange genetics are so insane that even the person who made this diagram just gave up. “The citron was crossed with a lemon to make a sour orange and then uhhhhhh some stuff happened! and you got a sweet orange.”

And this diagram:

We notice there are unlabeled spaces on this Venn diagram — apparently the citrus cartels are holding out on us. Where’s my micrantha x maxima hybrid???

And this diagram, in which the Bene Gesserit attempt to breed the Kumquat Haderach. No, really.

The written material on the subject is, if anything, even more disheartening. Let’s look at a couple passages from the Wikipedia article on citrus taxonomy:

Citrus taxonomy is complex and controversial. Cultivated citrus are derived from various citrus species found in the wild. Some are only selections of the original wild types, many others are hybrids between two or more original species, and some are backcrossed hybrids between a hybrid and one of the hybrid’s parent species. Citrus plants hybridize easily between species with completely different morphologies, and similar-looking citrus fruits may have quite different ancestries. … Conversely, different-looking varieties may be nearly genetically identical, and differ only by a bud mutation.

The same common names may be given to different species, citrus hybrids or mutations. For example, citrus with green fruit tend to be called ‘limes’ independent of their origin: Australian limes, musk limes, Key limes, kaffir limes, Rangpur limes, sweet limes and wild limes are all genetically distinct. Fruit with similar ancestry may be quite different in name and traits (e.g. grapefruit, common oranges, and ponkans, all pomelo-mandarin hybrids). Many traditional citrus groups, such as true sweet oranges and lemons, seem to be bud sports, clonal families of cultivars that have arisen from distinct spontaneous mutations of a single hybrid ancestor. Novel varieties, and in particular seedless or reduced-seed varieties, have also been generated from these unique hybrid ancestral lines using gamma irradiation of budwood to induce mutations.

For more on using radiation to make new fruit, please refer to these talking dinosaurs.

In case that isn’t weird enough for you, there’s even a graft chimera citrus called the Bizzaria (really), which produces fruits that look like this: 

We’re at the Florentine citron. We’re at the sour orange. We’re at the…

On limes in particular, this page says: 

Limes: A highly diverse group of hybrids go by this name. Rangpur limes, like rough lemons, arose from crosses between citron and mandarin. The sweet limes, so-called due to their low acid pulp and juice, come from crosses of citron with either sweet or sour oranges, while the Key lime arose from a cross between a citron and a micrantha.

All of these hybrids have in turn been bred back with their parent stocks or with other pure or hybrid citrus to form a broad array of fruits. Naming of these is inconsistent, with some bearing a variant of the name of one of the parents or simply another citrus with superficially-similar fruit, a distinct name, or a portmanteau of ancestral species.

While most other citrus are diploid, many of the Key lime hybrid progeny have unusual chromosome numbers. For example, the Persian lime is triploid, deriving from a diploid Key lime gamete and a haploid lemon ovule. A second group of Key lime hybrids, including the Tanepao lime and Madagascar lemon, are also triploid but instead seem to have arisen from a backcross of a diploid Key lime ovule with a citron haploid gamete. The “Giant Key lime” owes its increased size to a spontaneous duplication of the entire diploid Key lime genome to produce a tetraploid. [Editor’s note: uhhhhh]

Wikipedia tells us this is a “lumia”. W-what is that? We don’t know, but Wikipedia assures us that “like a citron, it can grow to a formidable size.”

Pretty much every citrus page on Wikipedia has shit like this, truly enough to drive a man mad. You wander onto Wikipedia trying to find out what in god’s name a lumia is, and soon you are reading this: “A recent genomic analysis of several species commonly called ‘lemons’ or ‘limes’ revealed that the various individual lumias have different genetic backgrounds. The ‘Hybride Fourny’ was found to be an F1 hybrid of a citron-pomelo cross, while the ‘Jaffa lemon’ was a more complex cross between the two species, perhaps an F2 hybrid. The Pomme d’Adam arose from a citron-micrantha cross, while two other lumias, the ‘Borneo’ and ‘Barum’ lemons, were found to be citron-pomelo-micrantha mixes.” Lovecraft, eat your heart out. 

Mr Lovecraft might also enjoy this lovely citro-AAAAAAH

This is the much deeper problem that the history of scurvy reveals. In science, you need tools you can trust. You need to have the right equipment, the right study design, and the right analysis techniques — but you also need the right concepts.

Most of us are trained to calibrate our equipment and to double-check our experimental designs, but how often do we reconcile our concepts? Back in the 1800s, they trusted the terms “lemon” and “lime” to be relevant, to be reliable, to be meaningful — and to be interchangeable, to mean the same thing as each other. But they were all of them, deceived. 

This will continue to be a problem forever. We distinguish between lemons and limes today, and we’re better off for it, but we aren’t safe and can’t afford to forget this problem. “Lime” is still considered a perfectly good tool, and if you were going to do a study on whether limes are good for your heart or something, no one except for citrus geneticists would think anything of it.

But “lime”, as we have hopefully convinced you today, is not a good category at all! It’s not a good tool. You can’t trust it. Yet the assumption that “lime” is a perfectly normal category is so deeply embedded that you never realized it was an assumption.

Evaluating simple propositions like “limes cure scurvy” depends on accepting that “limes”, “scurvy”, and even “cure” are coherent and meaningful concepts. But they may not be!

The TRUE way that reality is very weird is that words and concepts that you use every day and take entirely for granted may be just as incoherent as the term “lime”. Concepts you think of as normal may some day seem as crazy as using the words “lemon” and “lime” interchangeably for all citrus fruits. We can pretty much guarantee that this will happen for something.

In our last post we described “splitting” as the practice of coming up with weird special cases or new distinctions between categories in the face of contradictory evidence. Splitting concepts is especially risky, in part because concepts are so powerful. If there is a confusion of categories, then all the research up to that point will be hopelessly confused as well, entirely muddled.

But if you split the categories in a better way, you will suddenly be left facing nothing but low-hanging fruit — be they lemons, limes, other limes, grapefruits, other other limes, clementines, pomelos, lumias, etrogs, etc.

Reality is Very Weird and You Need to be Prepared for That

I. 

Maciej Cegłowski’s essay Scott And Scurvy is one of the most interesting things we’ve ever read. We keep coming back to it — and we hope to write more about it in the future — but today we want to start with just how weird the whole thing is.

Scott and Scurvy tells the true history of scurvy, a horrible and dangerous disease. Scurvy is the result of a vitamin C deficiency — if you’re a sailor or something, eating preserved food for months on end, you eventually run out of vitamin C and many horrible things start happening to your body. If this continues long enough, you die. But at any point, consuming even a small amount of vitamin C, present in most fresh foods, will cure you almost immediately. 

We can’t do the full story justice (read the original essay, seriously), but just briefly: The cure was repeatedly discovered and lost by different crews of sailors at different points in time. Then in 1747, James Lind tried a bunch of treatments and found that citrus was more or less a miracle cure for the disease. Even so, it took until 1799, more than 50 years, for citrus juice to become a staple in the Royal Navy. 

Instead of diagrams depicting the horrifying symptoms of scurvy, please enjoy this picture of James Lind shoving a whole lemon into some unfortunate sailor’s mouth.

Originally, the Royal Navy was given lemon juice, which works well because it contains a lot of vitamin C. But at some point between 1799 and 1870, someone switched out lemons for limes, which contain a lot less vitamin C. Worse, the lime juice was pumped through copper tubing as part of its processing, which destroyed the little vitamin C that it had to begin with. 

This ended up being fine, because ships were so much faster at this point that no one had time to develop scurvy. So everything was all right until 1875, when a British arctic expedition set out on an attempt to reach the North Pole. They had plenty of lime juice and thought they were prepared — but they all got scurvy. 

The same thing happened a few more times on other polar voyages, and this was enough to convince everyone that citrus juice doesn’t cure scurvy. The bacterial theory of disease was the hot new thing at the time, so from the 1870s on, people played around with a theory that a bacteria-produced substance called “ptomaine” in preserved meat was the cause of scurvy instead. 

This theory was wrong, so it didn’t work very well. Everyone kept getting scurvy on polar expeditions. This lasted decades, and could have lasted longer, except that two Norwegians happened to stumble on the answer entirely by accident: 

It was pure luck that led to the actual discovery of vitamin C. Axel Holst and Theodor Frolich had been studying beriberi (another deficiency disease) in pigeons, and when they decided to switch to a mammal model, they serendipitously chose guinea pigs, the one animal besides human beings and monkeys that requires vitamin C in its diet. Fed a diet of pure grain, the animals showed no signs of beriberi, but quickly sickened and died of something that closely resembled human scurvy.

No one had seen scurvy in animals before. With a simple animal model for the disease in hand, it became a matter of running the correct experiments, and it was quickly established that scurvy was a deficiency disease after all. Very quickly the compound that prevents the disease was identified as a small molecule present in cabbage, lemon juice, and many other foods, and in 1932 Szent-Györgyi definitively isolated ascorbic acid.

Even in retrospect, the story is pretty complicated. But we worry that it would have looked even messier from the inside.

II.

Holst and Frolich also ran a version of the study with dogs. But the dogs were fine. They never developed scurvy, because unlike humans and guinea pigs, they don’t need vitamin C in their diet. Almost any other animal would also have been fine — guinea pigs and a few species of primates just happen to be really weird about vitamin C. So what would this have looked like if Holst and Frolich just never got around to replicating their dog research on guinea pigs? What if the guinea pigs had gotten lost in the mail?

Three of Theodore Roosevelt’s children posing in a photo with one of their five guinea pigs. Kermit Roosevelt is holding the pig.

Let’s imagine a version of history where the guinea pigs did indeed get lost in the Norwegian mail, so Holst and Frolich only tested dogs, and found no sign of scurvy. Let’s further imagine that Frolich has been struck by inspiration, and through pure intuition has figured out exactly what is going on. 

Frolich: You know Holst, I think old James Lind was right. I think scurvy really is a disease of deficiency, that there’s something in citrus fruits and cabbages that the human body needs, and that you can’t go too long without. 

Holst: Frolich, what are you talking about? That doesn’t make any sense.

Frolich: No, I think it makes very good sense. People who have scurvy and eat citrus, or potatoes, or many other foods, are always cured.

Holst: Look, we know that can’t be right. George Nares had plenty of lime juice when he led his expedition to the North Pole, but they all got scurvy in a couple weeks. The same thing happened in the Expedition to Franz-Josef Land in 1894. They had high-quality lime juice, everyone took their doses, but everyone got scurvy. It can’t be citrus.

Frolich: Maybe some citrus fruits contain the antiscorbutic [scurvy-curing] property and others don’t. Maybe the British Royal Navy used one kind of lime back when Lind did his research but gave a different kind of lime to Nares and the others on their Arctic expeditions. Or maybe they did something to the lime juice that removed the antiscorbutic property. Maybe they boiled it, or ran it through copper piping or something, and that ruined it.

Holst: Two different kinds of limes? Frolich, you gotta get a hold of yourself. Besides, the polar explorers found that fresh meat also cures scurvy. They would kill a polar bear or some seals, have the meat for dinner, and then they would be fine. You expect me to believe that this antiscorbutic property is found in both polar bear meat AND some kinds of citrus fruits, but not in other kinds of citrus?

Frolich: You have to agree that it’s possible. Why can’t the property be in some foods and not others? 

Holst: It’s possible, but it seems really unlikely. Different varieties of limes are way more similar to one another than they are to polar bear meat. I guess what you describe fits the evidence, but it really sounds like you made it up just to save your favorite theory. 

Frolich: Look, it’s still consistent with what we know. It would also explain why Lind says that citrus cures scurvy, even though it clearly didn’t cure scurvy in the polar expeditions. All you need is different kinds of citrus, or something in the preparation that ruined it — or both! 

Holst: What about our research? We fed those dogs nothing but grain for weeks. They didn’t like it, but they didn’t get scurvy. We know that grain isn’t enough to keep sailors from getting scurvy, so if scurvy is about not getting enough of something in your diet, those dogs should have gotten scurvy too.

Frolich: Maybe only a few kinds of animals need the antiscorbutic property in their food. Maybe humans need it, but dogs don’t. I bet if those guinea pigs hadn’t gotten lost in the mail, and we had run our study on guinea pigs instead of dogs, the guinea pigs would have developed scurvy.

Holst: Let me get this straight, you think there’s this magical ingredient, totally essential to human life, but other animals don’t need it at all? That we would have seen something entirely different if we had used guinea pigs or rats or squirrels or bats or beavers?

Frolich: Yeah basically. I bet most animals don’t need this “ingredient”, but humans do, and maybe a few others. So we won’t see scurvy in our studies unless we happen to choose the right animal, and we just picked the wrong animal when we decided to study dogs. If we had gotten those guinea pigs, things would have turned out different.

III.

Frolich is entirely right on every point. He also sounds totally insane. 

Maybe there are different kinds of citrus. Maybe some animals need this mystery ingredient and others don’t. Maybe polar bear meat is, medically speaking, more like citrus fruit from Sicily than like citrus fruit from the West Indies. Really???

This looks a lot like special pleading, but in this case, the apparent double standard is correct. All of these weird exceptions he suggests were actually weird exceptions. And while our hypothetical version of Frolich wouldn’t have any way of knowing, these were the right distinctions to make. 

Reality is very weird, and you need to be prepared for that. Like the hypothetical Holst, most of us would be tempted to discard this argument entirely out of hand. But this weird argument is correct, because reality is itself very weird. Looking at this “contradictory” evidence and responding with these weird bespoke splitting arguments turns out to be the right move, at least in this case. 

Real explanations will sometimes sound weird, crazy, or too complicated because reality itself is often weird, crazy, or too complicated. 

It’s unfortunate, but scurvy is really the BEST CASE SCENARIO. The answer ended up being almost comically simple: it’s just a disease of deficiency, eat one of these foods containing this vitamin and be instantly cured. But the path to get to that answer was confusing and complicated. Think about all the things in the world that have a more complicated answer than scurvy, i.e. almost everything. Those things will have even weirder and more confusing stories to untangle.

This story has a couple of lessons for us. The first is just, don’t discard an explanation just because it’s weird or complicated. 

Focus on explanations that are consistent with all the evidence. Frolich’s harebrained different-citrus different-animals explanation from above does sound crazy, but at least it’s consistent with everything they knew at the time. If some kinds of citrus cured scurvy and other kinds didn’t, that would explain why it worked for Lind and for early sailors, but it didn’t work for the polar explorers after 1870. And in fact, that does explain it.  

It’s also testable, at least in principle. If you think there might be differences between different kinds of citrus fruits, you could go back and try to figure out the original source used by James Lind and the Royal Navy, and try to re-create those conditions as closely as possible.

FRUIT

We’re taught to see splitting  — coming up with weird special cases or new distinctions between categories — as a tactic that people use to save their pet theories from contradictory evidence. You can salvage any theory just by saying that it only works sometimes and not others — it only happens at night, you need to use a special kind of wire, the vitamin D supplements from one supplier aren’t the same as from a different supplier, etc. Splitting has gotten a reputation as the sort of thing scientific cheats do to draw out the con as long as possible.

But as we see from the history of scurvy, sometimes splitting is the right answer! In fact, there were meaningful differences in different kinds of citrus, and meaningful differences in different animals. Making a splitting argument to save a theory — “maybe our supplier switched to a different kind of citrus, we should check that out” — is a reasonable thing to do, especially if the theory was relatively successful up to that point. 

Splitting is perfectly fair game, at least to an extent — doing it a few times is just prudent, though if you have gone down a dozen rabbitholes with no luck, then maybe it is time to start digging elsewhere.

Scurvy isn’t the only case where splitting was the right call. Maybe there’s more than one kind of fat. Maybe there are different kinds of air. Maybe there are different types of blood. It turns out, there are! So give splitting a chance.

Be more forgiving of contradictory evidence. These days people like to put a lot of focus on the idea of decisive experiments. While it’s true that some experiments are more decisive than others, no experiment can be entirely decisive either for or against a theory. We need to stop expecting knock-down studies that solve things forever.

Contradictory evidence can be wrong! The person making the observations might have been confused. They might have done the analysis wrong. The equipment may have malfunctioned. They might have used dogs instead of guinea pigs, or they might have used the wrong kind of hamster. The data might even be fabricated! Shit happens. 

Things change as contradictory evidence piles up, but even then, it doesn’t mean you should scrap the theory you started out with. Everyone back in the 1870s made a big mistake throwing out their perfectly good “disease of deficiency” theory as soon as there were a few contradictory stories from polar explorers.

Their mistake was thinking “maybe the theory is wrong”, instead of “maybe the real theory is more complicated”. When you see evidence that goes against a theory, it could mean that you’ve been barking up the wrong tree. Or it could just mean that there’s a small wrinkle you aren’t aware of.

If you have a theory that’s been working pretty well for a while — it made good predictions, it solved real problems, it explained a lot of mysteries — you should stick with it in the face of apparent contradictions, at least for a while. When you hit a snag with a reliable theory, think “maybe it’s complicated” instead of “oh it’s wrong”. It may still be wrong, but it’s good to check!

Be careful of purely verbal, syllogistic reasoning. We make these arguments in conversation all the time. They seem plain, convincing, and commonsensical, but in reality they’re pretty weak. It’s hard to get away from commonsensical, verbal arguments since that’s how we naturally think, but don’t take them too seriously. They’re ok as starting points, but keep in mind that they’re not actually evidence.

“Different kinds of citrus fruits are more like one another than they are like polar bear meat” sounds very reasonable, but in this case it was wrong. Sicilian lemons really ARE more like polar bear meat than they are like West Indian limes, at least for the purposes of treating scurvy.

One of these things is not like the others. That’s right — the limes!

“Dogs are about as similar to humans as guinea pigs are” also sounds very reasonable. The three species are all the same class (Mammalia) but different orders (Carnivora, Primates, and Rodentia, respectively), so there seems to be some taxonomic evidence as well. But humans really are a lot more like guinea pigs than they are like dogs, or most other animals, at least for the purposes of getting scurvy.

IV.

We were tickled to see this paragraph near the end of Scott and Scurvy, for obvious reasons

…one of the simplest of diseases managed to utterly confound us for so long, at the cost of millions of lives, even after we had stumbled across an unequivocal cure. It makes you wonder how many incurable ailments of the modern world—depression, autism, hypertension, obesity—will turn out to have equally simple solutions, once we are able to see them in the correct light. What will we be slapping our foreheads about sixty years from now, wondering how we missed something so obvious?

This is really good, and we think it’s reason to be optimistic. We might be closer than we think to cures for depression, hypertension, and yes, even obesity

The answer to scurvy was just one thing, plus a few wrinkles — mostly “not all citrus has the antiscorbutic property” and “most animals can’t get scurvy”. This was only difficult because people weren’t prepared to deal with basic wrinkles, but we can do better by learning from their mistakes.

This means don’t give up easily. It suggests that there is lots of low-hanging fruit, because even simple explanations are easily missed.

Lots of theories have been tried, and lots of them have been given up because of something that looks like contradictory evidence. But the evidence might not actually be a contradiction — the real explanation might just be slightly more complicated than people realized. Go back and revisit scientific near-misses, maybe there’s a wrinkle they didn’t know how to iron out.