When I was in high school and college, I took for granted the stereotype of the “dumb jock.” It never occurred to me that this stereotype might be partly racist in origin, until I read The Sports Gene by David Epstein. Here from pages 180 and 184-185 is the key passage, which also hints at just how touchy it is to talk about the possibility of racial differences in physical attributes relevant to sports:
In his 2003 book, Black Superman: A Cultural and Biological History of the People Who Became the World’s Greatest Athletes, and then in his 2006 paper with [Errol] Morrison, [Patrick] Cooper first made the argument that West Africans evolved characteristics like a high prevalence of the sickle-cell gene mutation and other gene mutations that cause low hemoglobin for protection from malaria, and that an increase in fast-twitch muscle fibers followed from that, providing more energy production from a pathway that does not rely primarily on oxygen, for people who have reduced capacity to produce energy with oxygen. The former part of Cooper’s hypothesis–that sickle-cell trait and low hemoglobin are evolutionary adaptations to malaria–now seems undeniable. …
As for whether low hemoglobin in itself might prompt a switch to more fast-twitch fibers, there is evidence that it can in rodents. …
… No scientist has attempted to test Cooper and Morrison’s idea in humans, so there are simply no human studies at all.
Several scientists I spoke with about the theory in insisted that they would have no interest in investigating it because of the inevitably thorny issue of race involved. One of them told me that he actually has data on ethnic differences with respect to a particular physiological trait, but that he would never publish the data because of the potential controversy. Another told me he would worry about following Cooper and Morrison’s line of inquiry because any suggestion of physical advantage among a group of people could be equated to a corresponding lack of intellect, as if athleticism and intelligence were on some kind of biological teeter-totter. With that stigma in mind, perhaps the most important writing Cooper did in Black Superman was his methodical evisceration of any supposed inverse link between physical and mental prowess. “The concept that physical superiority could somehow be a symptom of intellectual inferiority only developed when physical superiority became associated with African Americans,” Cooper wrote. “That association did not begin until about 1936.” The idea that athleticism was suddenly inversely proportional to intellect was never a cause of bigotry, but rather a result of it. And Cooper implied that more serious scientific inquiry into difficulty issues, not less, is the appropriate path.
The idea of prejudice against African Americans begetting prejudice against jocks reminds me of a similar phenomenon I heard about in a Unitarian-Universalist sermon: apparently, some of the prejudice against male homosexuals originally came from the idea that they were like women. (Along those lines, I remember in middle school hearing some of my age-mates use “fem” as an anti-male-homosexual insult.) Thus, prejudice against women generated part of the prejudice against gay men.
The teacher of a class on Plato I audited when I was a grad student at Harvard maintained that for the ancient Athenians, prejudice against women generated a more pro-homosexual attitude for men, since they focused on the higher status of a male as an object of sexual desire rather than any supposed similarity of a gay man to a woman. The common element between ancient Athenian pro-homosexual attitudes and modern American anti-homosexual attitudes would then be prejudice against women. (The Wikipedia article on “Homosexuality in ancient Greece” emphasizes yet other aspects of how prejudice against women affected attitudes toward homosexuality.)
The bottom line is that prejudice affects everything it touches.