Furthermore, unlike with the charge of the electron, there is no strong reason to believe the value is a constant. In fact, it is known to be variable, and that variability has been recognized as diagnostic (which is why we have a lot of measurements.)
As others have pointed out, the authors have considered, in detail, several conceivable sources of systematic error. We probably should not approach studies with the expectation that the people performing them are naive.
That said I think skepticism is always healthy when done in good faith and is a driving factor in increasing our knowledge.
> To minimize these biases, we examined changes in body temperature by birth decade within each cohort under the assumption that the method of thermometry would not be biased on birth year.
For my Japanese wife, 37C means you may starting to get sick. you should be in the 36s.
Just an anecdote, but the normal temperature could vary among population, latitude, weather conditions...
https://www.bmj.com/content/359/bmj.j5468
Results:
In a diverse cohort of 35 488 patients (mean age 52.9 years, 64% women, 41% non-white race) with 243 506 temperature measurements, mean temperature was 36.6°C (95% range 35.7-37.3°C, 99% range 35.3-37.7°C). Several demographic factors were linked to individual level temperature, with older people the coolest (–0.021°C for every decade, P<0.001) and African-American women the hottest (versus white men: 0.052°C, P<0.001). Several comorbidities were linked to lower temperature (eg, hypothyroidism: –0.013°C, P=0.01) or higher temperature (eg, cancer: 0.020, P<0.001), as were physiological measurements (eg, body mass index: 0.002 per m/kg2, P<0.001). Overall, measured factors collectively explained only 8.2% of individual temperature variation. Despite this, unexplained temperature variation was a significant predictor of subsequent mortality: controlling for all measured factors, an increase of 0.149°C (1 SD of individual temperature in the data) was linked to 8.4% higher one year mortality (P=0.014).
The EN and FR wikipedia state different values.
FR:
> On considère généralement que la température basale usuelle du corps humain est de 37,0 °C, [...] Une température corporelle normale se situe entre 36,1 °C et 37,8 °C
Baseline : 37C. Normal range, [36.1 - 37.8]
EN:
No baseline, provided,just a range:
> The normal human body temperature range is typically stated as 36.5–37.5 °C (97.7–99.5 °F).
The French version explains that for a long time, until the 1980s, everybody assumed correct a study made in 1868 about the body temperature that found 37.0 - 37.5 to be the normal range in healthy adults.
It suggests that the declining prevalence of infections in the population may be the exaplanation of the lowering of the average body temperature.
After all, one of the main causes of rising temperature is an active immune system. Lower temperatures in the population are actually good news.
It probably may also depend on where the temperature is taken. In USSR/Russia it is in the armpit, which is probably of lower temperature than anus/mouth which is where the temperature is taken in many other countries.
BMI as a health metric is downright lazy mathematically in that it doesn't use a cubic portion and thus gives more undue "slack" in its judgement for shorter and less for taller.
I am uncertain what aspect if any dominates. It could be that without sufficent HVAC exposure the local climate causes the body to adapt and dominate. Granted not allowing that adaptation may not just be "softness" and "disconnection from nature from arrogance". Apparently according to some accounts colonialists in the tropic were looked upon by natives as fools and lunatics for being physically active during the hot and bright sun instead of resting then and saving activity for when it is cooler.
Why were people not able to find this error?
And if you haven't seen it, it's fantastic. As is the whole lecture, 5 minutes you really won't regret.
"We have learned a lot from experience about how to handle some of the ways we fool ourselves. One example: Millikan measured the charge on an electron by an experiment with falling oil drops and got an answer which we now know not to be quite right. It’s a little bit off, because he had the incorrect value for the viscosity of air. It’s interesting to look at the history of measurements of the charge of the electron, after Millikan. If you plot them as a function of time, you find that one is a little bigger than Millikan’s, and the next one’s a little bit bigger than that, and the next one’s a little bit bigger than that, until finally they settle down to a number which is higher.
Why didn’t they discover that the new number was higher right away? It’s a thing that scientists are ashamed of—this history—because it’s apparent that people did things like this: When they got a number that was too high above Millikan’s, they thought something must be wrong—and they would look for and find a reason why something might be wrong. When they got a number closer to Millikan’s value they didn’t look so hard. And so they eliminated the numbers that were too far off, and did other things like that." [1]
Needless to say the actual charge on an electron is very likely to have been constant over that period rather than trending steadily upward.
[1] http://calteches.library.caltech.edu/51/2/CargoCult.htm