“Dad,” my ten-year-old daughter asked, “why are all the fast runners dark people?”

We were watching the Olympics. Maybe it was one of the triumphs of the magnificent Usain Bolt, or maybe the U.S. women sweeping the 100-meter hurdles. But it could have been any world-class sprint competition over the past half-century, where runners of African origin have become so dominant, one can hardly recall a white champion. (Where are you, Valery Borzov?)    

I sighed, reluctant to step into the minefield my daughter’s question opened up. An innocent question, yes, but it vectored toward places and ideas—tainted by political domination, racism, and corrupt science—where innocence has not exactly been the rule. In this fraught context, the white American liberal tends to worry that even talking about innate athletic aptitudes risks bolstering racist views—since if genetically determined physical differences exist between races, might it not be argued that psychological and cognitive ones do too? Or, as the sportswriter Frank Deford once remarked, “People feel if you say blacks are better athletically, you're saying they’re dumber.”

Partly for this reason, liberal white Americans tend, when trying to account for black sports dominance, to lean instinctively on environmental factors, stressing the dynamic of opportunity and exclusion. A set-piece in this interpretation is the “Jewish basketball” story, which takes up the overrepresentation of Jews in semipro basketball in the 1920s and 30s. Once Jews stopped being excluded from other, more central arenas of American accomplishment, this story reminds us, their dominance on the basketball court evaporated—but not before commentators had made all sorts of bogus and invidious judgments about Jewish hoop prowess. Paul Gallico, a well-known sportswriter of the day, wrote that “basketball appeals to the Hebrew, with his Oriental background,” because “the game places a premium on an alert, scheming mind, flashy trickiness, artful dodging and general smart-aleckness.” Hmmm.

One problem with using this case as a template to problematize the idea of group athletic dominance is that Jews were never truly dominant in basketball, certainly not in any way remotely comparable to the dominance of black runners. How dominant are black runners, exactly? In men’s track, athletes of African ancestry hold every major record in all running events, from the 100m to the marathon. Every last one of the 64 finalists in the hundred-meter dash in the last eight Olympics has been of African descent. Only two white runners hold places in the top 500 times ever posted in the 100 meter sprint. And similar racial dominance characterizes the long-distance running contests.

In trying to make sense of this, it’s important to note that “running” isn’t dominated by “black” athletes per se. The sprinters aren’t “black,” they are of West African origin. The distance runners aren’t “black,” they’re East African. And the “running” depends on what distance you’re talking about. Dominance turns out to be both task-specific and origin-specific. Consider the contours of Jamaican accomplishments in track. While Jamaican runners—whose ethnic roots are in West Africa—have produced the fastest 100 m and 200 m sprints in the world (by Usain Bolt), their best finish at 400m is 41st, at 800m 2887th, and at 1500m 7836th. In other words, Jamaican prevalence diminishes geometrically with increased distance. And an inverse structure of frequency would hold with East African runners. So what is it about these particular origins and particular distance aptitudes?

Two recent articles offer contending explanations. In “The Secret of Jamaica’s Runners,”  renowned Harvard sociologist Orlando Patterson both celebrates and dissects “the astonishing supremacy” of his native country’s runners. Patterson all but dismisses the idea of genetic advantage, attributing Jamaica’s success first to an institutional and cultural history, derived from British colonialism, that elevated track to supreme status, and second to “an abundance of very healthy children and young people,” which he traces to “the extraordinary success of a public health campaign partly spearheaded in the 1920s by specialists from the Rockefeller Foundation.” Beyond that, he asserts, there’s Jamaica’s “combative individualism,” which in his view unfortunately feeds his country’s “chronic violence,” but also “dovetails nicely with running, in which performance is entirely up to the athlete.” Jamaican sprinting dominance is about nurture, in other words. Culture.

A contrary take comes from journalist Jon Entine, whose 2000 book, Taboo: Why Black Athletes Dominate Sports and Why We Are Afraid to Talk About It, argued that genetics forms “a significant component” of the “stunning and undeniable dominance of black athletes.” Entine dismisses Patterson’s article as “a politically correct narrative” flawed by “ignorance of basic population genetics.” He acknowledges the cultural factors Patterson lists, but insists that “culture alone can only take one so far;” beyond that, we have to turn to biology. Entine cites such factors as ACTN3, the so-called “speed gene;” differences in skeletal structure and leg length; fast-twitch versus slow-twitch muscles; differential lung capacities, levels of plasma testosterone, anaerobic enzymes, and the like. These “genetically linked, highly heritable characteristics” determine outcomes across various contests, he writes, and “they are not evenly distributed among human populations.” For instance, “the East African’s outsized natural lung capacity and preponderance of slow-twitch muscles [make] a perfect biomechanical package for long-distance running, but a disaster for sports that require anaerobic bursts.” Whites, meanwhile, tend to be mesomorphic, possessing larger bodies with comparatively short limbs and thick torsos. “These proportions are advantageous in sports in which strength rather than speed is at a premium... [such as] weightlifting, wrestling, and the shot put and hammer.”

Entine sums up:

Human genome research... offers clues to solving the mystery of diseases, the Holy Grail of genetics. So why do we readily accept that evolution has turned out Jews with a genetic predisposition to Tay-Sachs, Southeast Asians with a higher proclivity for beta-thalassemia, and blacks who are susceptible to colorectal cancer and sickle-cell disease, yet find it inappropriate to suggest that Usain Bolt can thank his West African ancestry for the most critical part of his success?

And:

[W]hen it comes to performance, genes circumscribe possibility. Scientists firmly reject the blank slate theory that all human populations are born with an equal chance to succeed in athletics. Evolution has shaped significant physical and physiological differences.... No one outside of the most politically correct circles really believes that the purely cultural theories capture the real story of black domination of running.

As you can imagine, my daughter was basically asleep by now, proving yet again the efficacy of that venerable parental tactic, the filibuster. But for those of you still paying attention, I’ll close by passing along a 1997 essay, The Sports Taboo, by New Yorker writer Malcolm Gladwell. Gladwell, who grew up in an Afro-Caribbean-Canadian family, was a superlative competitive runner in high school, and he dispenses quickly with the taboo against raising the question of African superiority. “There is a point at which it becomes foolish to deny the fact of black athletic prowess, and even more foolish to banish speculation on the topic,” he writes. “Clearly, something is going on. The question is what.”

Having raised the prospect of genetically-determined black athletic dominance, Gladwell then undermines the idea, examining not merely the evidence, but the structures that govern how we draw conclusions from it. “If we are to decide what to make of the differences between blacks and whites,” he writes, “we first have to decide what to make of the word ‘difference.’” To this end, he provides a primer on statistics for the lay reader. Comparing the differences in black and white running performance with those between men and women in math, he explains that black runners, like males in math, show more variability, notching both higher scores and lower scores. He then explores why African genes may be more variable—across a range of realitie—than others, speculating that “since every human population outside Africa is essentially a subset of the original African population, it makes sense that everyone in such a population would be a genetic subset of Africans, too. So you can expect groups of Africans to be more variable in respect to almost anything that has a genetic component.”

Beyond such statistical problems, Gladwell focuses the way racial expectation can feed performance. “The education of any athlete begins, in part,” he writes, “with an education in the racial taxonomy of his chosen sport—in the subtle, unwritten rules about what whites are supposed to be good at and what blacks are supposed to be good at.” As a young athlete he himself unquestioningly accepted the idea of black superiority in track, so that the whiteness of one competitor seemed like “a degenerative disease, which would eventually claim and cripple him.” The story reveals how racial ideology gets reified as a fact of nature, and then, via a kind of psychological feedback loop in both black and white athletes, becomes self-fulfilling prophecy.

Gladwell’s skeptical view insists that any attempt to ascertain genetic racial athletic superiority must attach big caveats. To my mind, the most important is that fixating on differences at the very tip of human capacities almost inevitably creates a misleading impression of group difference. In statistical terms, margins get confused with means, variability differences with average differences. It’s like those misleading bar graphs that only show the very tops of the bars. Tiny differences look large at the tips, obscuring the huge overlap down below.

At the level of daily real life, in other words, there is nothing to suggest that the average black person runs any faster than the average white person. Anyone who surveys the Olympic starting blocks and concludes anything about the guy who lives down the block is committing what Germans call a Denkfehler—a failure of thinking, riding faulty logic toward false conclusions. Nor, finally, does the possibility that genetic differences may determine small but decisive advantages among world-class athletes hold any implication for  character, personality, intelligence, or any of the myriad factors that make up the individual human being as we know him or her in the real world.

Are black athletes better because of their genetic heritage? Maybe it’s not possible to know with certainty. And maybe there’s no need to know. As one reviewer of Jon Entine’s book asked, “why go on about how, genetically speaking, ‘white men can’t jump,’ if it has no practical effect other than to deepen our sense of racial separateness?” This might be the most profound—and provocative—question raised here. Do all observable realities need explanation, simply because they are observable? Or are some things that might be known not worth knowing? What is the utility of attempting to establish hierarchies of racial ability? Gladwell, after noting the preeminent role of desire, commitment and tunnel vision in determining athletic excellence, comments that “the problem, in the end, with the question of whether blacks are better at sports than whites [is] not that it’s offensive, or that it leads to discrimination. It’s that, in some sense, it’s not a terribly interesting question; ‘better’ promises a tidier explanation than can ever be provided.”

How should we proceed when the potential costs of knowing something outweigh the value of knowing it? Or are such dilemmas merely the product of an approach to knowledge hampered by, well, political correctness? Jon Entine sees himself as mounting a defense of science against taboo, and seems almost eager to risk stoking racist animus in order to maintain the viability of addressing all realities scientifically. “We have no choice,” he muses dramatically, “but to face this third rail of genetics and sports.” Such aggressive confidence would seem to fail to acknowledge how often, and how brazenly, science in the past has been used to charge the third rail of American racism.