It’s interesting how so many people who consider themselves pro-science uncritically accept scientific papers and reports as fact, when such reporting may either be wrong, misconstrued by whoever is doing the reporting, or merely a hypothesis. Science, unlike, say, originalism, is supposed to be provisional and amenable. Except for things which can be definitively or quantifiably proven, like the existence of something , one cannot take science reporting as being in the same realm as fact.
The replication crisis shows why a high degree of skepticism is necessary when appraising science results. It is estimated that at least 50 percent of studies published in psychology journals fail to replicate. Recent notable examples include priming and the implicit racism or ‘racism by association’ hypothesis. Failure to replicate can occur for many reasons, such as the results being spurious, but in more serious cases, fraud or misconduct (e.g. Marc Tessier-Lavigne, Francesca Gino, and Dan Ariely).
Other examples include the food pyramid and the notion that humans need ‘eight glasses of water a day’, both of which have come under doubt or have no actual scientific basis or backing. I am sure many people recall seeing the food pyramid in school, and unquestionably assumed it was correct or true because scientists created it or reputable media sources reported it as fact.
One such example of a recent hypothesis in which much more skepticism is merited is the endurance running hypothesis, which has gotten considerable attention in recent years:
A telltale sign of dubious science is if the results does not align with empirical reality. Sure, anecdotes are not data, but some things are too obvious to sweep under the rug of science or to suspend skepticism. Imagine if a ‘reputable’ source reported a study that individual human cognitive differences do not exist. Sure, it must be true because it’s a study, right? But this goes against empirical reality that some people are indeed smarter than others, like processing speed and recall. It may not be IQ, but one gets the sense by conversing or dealing with others that some people are slower on the uptake than others.
Going back to the hypothesis, the problem is two-fold: I agree that humans evolved or are specialized for short bursts of speed to possibly catch, ambush, or corner prey, but not for long-distance running to chase prey to exhaustion. Second, baked into the media’s reporting is the claim that all humans are born to be good endurance runners, such as the recent article Why are humans such good distance runners?, as if this applies to humans in general instead of only a small subset of them who are good distance runners. Yet, empirically, we see considerable variation of individual running ability, suggesting it’s uncommon or specialized, not innate or uniform to humans as a whole.
The popularity of the hypothesis can be explained by how people want to believe anything is possible with willpower, whether it’s curing obesity or running a marathon. When I critique this hypothesis, the response I typically get is people need to train, and then anyone can run long distances. But then it’s no longer instinctual. If people have to will themselves into being better long-distance runners, then it’s not the same thing as having evolved to do it. It’s not like birds have to be taught to fly, fish have to be taught to swim, or leaf-cutter ants need to be taught how to cut leaves. Cheetahs don’t need training to run fast. Moreover, the ability is uniform; it’s not like some leaf-cutter ants are unable to cut leaves as well compared to others.
During high school only a small percentage of the boys in my class could run a mile at a good time. The majority either could not finish or struggled, or had a mediocre time. It’s not like those who were unable to finish were obese or had other outwardly evident medical conditions, but for whatever reason lacked the stamina to do it. Maybe they got cramps or tightness. Or flat feet, poor oxygen uptake, or low lactic acid threshold. There are a multitude of reasons why many people cannot run long distances well. With practice sure they could have gotten better, but again, it ceases being instinctual. However, even the worst runners could at least run short distances until gasping for breath or cramping up.
Even now when I try endurance sports, after a few hours or miles, my lower legs turn into lead blocks and I start getting really tired, my calves hurt, and my mouth becomes parched no matter how much I drink. This is even after losing 60lbs to achieve a healthy BMI and practicing for years. Maybe eating more carbs to replete my glycogen stores would help or doing stretches beforehand, but this again goes back to my original point: if humans have to make a conscious effort to eat a special diet to run long distances, then it’s not instinctual or evolutionary. It’s not like animals in the wild need to ‘carb up’ or do stretches to avoid fatigue.
Indeed, for something which is supposedly innate and confers some major evolutionary advantage, except for a small minority who are seemingly born runners or have a knack for distance running, many humans sure seem to struggle, as evidenced by the popularity of apps such as Couch to 5k, which as of 2024 had 7 million downloads, as well as anecdotal evidence of people struggling at running (and they aren’t all obese):
But it’s not like some chimpanzees struggle at swinging from trees due to poor stamina or cramps. It’s an ability that is uniformly distributed among the species.
Additionally, decent marathon runners tend to fit a common anatomical profile, being thin-boned and light. Yet look around at how diverse humans are: some or short and stocky, others tall and slim, some in-between. Endurance runners are slow-twitch dominant, as opposed to fast-twitch dominant sprinters or weightlifters. The fact that these differences exist further casts doubt on the hypothesis. The slow-twitch guys with bulky skeletons and thick limbs are sure gonna struggle at the marathon, compared to the slim-boned runners with long tendons and small calves. I think it’s more like, humans evolved the capability to run long distances, unlike other animals. But due to innate individual differences (e.g. oxygen uptake, lactic acid threshold etc.) only some are capable of doing so, just like how all humans have some capacity for understanding abstractions, but only some are smart enough to learn calculus.