I am beginning to suspect that it is surprisingly common for intelligent, competent adults to somehow make it through the world for a few decades while missing some ordinary skill, like mailing a physical letter, folding a fitted sheet, depositing a check, or reading a bus schedule. Since these tasks are often presented atomically - or, worse, embedded implicitly into other instructions - and it is often possible to get around the need for them, this ignorance is not self-correcting. One can Google "how to deposit a check" and similar phrases, but the sorts of instructions that crop up are often misleading, rely on entangled and potentially similarly-deficient knowledge to be understandable, or are not so much instructions as they are tips and tricks and warnings for people who already know the basic procedure. Asking other people is more effective because they can respond to requests for clarification (and physically pointing at stuff is useful too), but embarrassing, since lacking these skills as an adult is stigmatized. (They are rarely even considered skills by people who have had them for a while.)
This seems like a bad situation. And - if I am correct and gaps like these are common - then it is something of a collective action problem to handle gap-filling without undue social drama. Supposedly, we're good at collective action problems, us rationalists, right? So I propose a thread for the purpose here, with the stipulation that all replies to gap announcements are to be constructive attempts at conveying the relevant procedural knowledge. No asking "how did you manage to be X years old without knowing that?" - if the gap-haver wishes to volunteer the information, that is fine, but asking is to be considered poor form.
(And yes, I have one. It's this: how in the world do people go about the supposedly atomic action of investing in the stock market? Here I am, sitting at my computer, and suppose I want a share of Apple - there isn't a button that says "Buy Our Stock" on their website. There goes my one idea. Where do I go and what do I do there?)
Yes, but that shows that Eliezer probably misremembered what the 40% referred to. In that study, "40%" refers not to how many didn't benefit, but rather to the maximal benefit on a particular measure of fitness received by any of the participants:
Alternately, he might've been rounding the subsequent statistic:
So, how many is many? What fraction of the subjects were resistant on the various metrics? Unfortunately, the NS article doesn't give exactly what we want to know, so we need to find the original scientific papers to figure it out ourselves, but the NS article doesn't give citations either, forcing us to fact-check it the hard way (a long time in Google Scholar punching in names and keywords).
Tracking down sources for this article is quite difficult. Bouchard quickly pulls up a bunch of papers all revolving around similar data from what is called the HERITAGE Family Study, which has apparently been running since 1995 (the abstract to "The HERITAGE family study: Aims, design, and measurement protocol", 1995, describes it as in-progress) and there are a lot of papers on various minutia of it. So we need to search with 'HERITAGE'.
The final paragraph about the 51/72 genes seems to be sourced from "Endurance training-induced changes in insulin sensitivity and gene expression", which was published around 2004, consistent with the NS date. The general stuff about responses to exercise is much harder to track down, but after quite a bit of browsing through Google Scholar, I think it's all summarized in "Individual differences in response to regular physical activity", Bouchard & Rankinen 2001, which sounds promising since its abstract mentions "For example, Vo2_max responses to standardized training programs have ranged from almost no gain up to 100% increase in large groups of sedentary individuals".
This review covers 4 major categories:
VO2_max: "The average increase reached 384 mL O 2 with an SD of 202 mL O 2"; citing:
heart-rate during exercise, "heart rate during submaximal exercise at 50 W" ; "A mean decrease of 11 beats·min -1 was observed among the 727 subjects with complete data. However, the SD reached 10 beats."
blood lipids, HDL-C: "They found that when the distribution of the percent changes in HDL-C was broken down into quartiles, the first quartile actually experienced a decrease in HDL-C of 9.3%, whereas the fourth quartile registered a mean increase of 18%." Cited to:
blood pressure, "systolic blood pressure during exercise in relative steady state at 50 W"; "Among these subjects, the mean decrease in SBP during cycling at 50 W was 8.2 mm Hg (SD 11.8)"
So that covers 4 of the markers mentioned in the NS link. In those 4 cases, going by the graphs (the data is highly non-normal so you can't just estimate from the mean/SD), I'd guesstimate that 5-20% of each show <=0 benefit from the 20-weeks of endurance exercise.
That leaves the insulin sensitivity one, which seems to be "Effects of Exercise Training on Glucose Homeostasis: The HERITAGE Family Study", Boulé et al 2005. The graphs are hilarious, almost exactly 50-50 looking, and so correspond to the NS summary of 58%/42%.
(The papers don't seem to include any correlation matrixes, but this is definitely a problem which calls out for dimensionality reduction: presumably resistance on all 4 measurements correlates and you could extract a 'exercise resistance factor' which would be more informative than looking at things piecemeal. Since correlations between the 4 measurements are not given, it's possible that they are independent and so only ~0.2^4 or <1% of the subjects were exercise-resistant on all 4 measures, but that would surprise me: it would be strange if one's insulin improved but not VO2_max or cholesterol. I don't have any guesses on how large this 'exercise-resistant factor' might be, though.)
Not all of these are as important as one another and weight does not seem to be included judging by Bouchard's silence on individual differences w/r/t that. He does cite some interesting studies on resistance of body weight to change like two twin studies.
So going by the HERITAGE data described in that NS link, exercise resistance is a thing in maybe a fifth of the population but mostly on invisible things. 40%, however, is too high, since only 1 of the 5 measured things seemed to go that high, and the specific fractions were not mentioned, so most likely Eliezer was misremembering the other two stats as the more important stat.
Do you have an opinion concerning whether this is better characterized as "non-response to the benefits of exercise due to pathology" vs. "immunity to the harmful effects of a sedentary lifestyle"?
Basically, is being a non-responder good or bad? Eyeballing that graph it does look like untrained non-responders might be a bit fitter than responders - but of course the first thing we should assume is ceiling effect.
(And of course there's many 3rd options - orchid/dandelion trade offs and such)