In lieu of an abstract, here is a brief excerpt of the content:

144 H UMAN BEINGS vary. That is no surprise. Everyone knows that some people are better poker players than others, that pearl divers can hold their breath longer than bus drivers can, and that some landlubbers can shimmy up coconut trees without any apparent effort, leaving the rest of us scratching our heads at the bottom and wondering how they do it. Over the years the many ways in which people can and do vary have been intensively scrutinized, at the individual level as well as at the “racial” one. In the former case you have the problem that is always present when you study unique phenomena: a lack of perspective. We remember years ago reading a research article co-authored by at least a dozen different scientists but devoted to one single outstanding runner, Peter Snell. It was impossible not to conjure up images of Snell standing patiently like Michelangelo’s David, while a legion of gnomes in white lab coats scurried up and down ladders braced against his torso, brandishing tape measures and calipers. The image was hilarious, but it didn’t disguise the fact that all you could ultimately conclude from the scientific data presented was that Snell was a remarkable individual—and the next question was, of course, “compared to whom?” For in the end all individuals are simply floating points, and to make sense of them you have to place them within a group. Yet we’ve already seen—and will see again, in more detail—how frequently it is difficult or impossible to assign individuals to groups that can usefully be compared—especially groups defined by more than one trait. And if you can’t characterize your groups effectively, you’re pretty much at a dead end. So while looking at variations purely among individuals is a lot easier than defining groups, on its own it is a pretty boring exercise that would probably make your IS“RACE”ABIOLOGICALPROBLEM? CHAPTER 4 IS “RACE” A BIOLOGICAL PROBLEM? 145 cocktail party companions move discreetly but rapidly toward the bar as soon as you raised the subject. Worse, if such tedium bothers you, and you want to go any further than mere observation, things rapidly get complicated again. This is because humans are biological creatures, which means that every individual is the outcome of a long and intricate process of negotiation between its genotype and the environment that surrounds it. So as soon as you have identified a difference and want to start asking such questions as “why?” you run smack dab into the problem of knowing whether the attribute in question is acquired, or inherited, or something in between. Does it result from years of painstaking and sometimes painful practice, or is it simply the genetic luck of the draw? Or—in the event the attribute in question is a desirable one—is there anything you can do to improve your own performance, even if optimization may be out of reach? Well, only identical twins have precisely the same genomes, and everybody, without exception, will have had different backgrounds and experiences. Even in the case of those identical twins, birth order will have made a difference, right from the beginning. As a result of complications like this, any potential intrinsic and extraneous influences on what you are observing are very difficult to control for. What’s more, even if you can devise a way of controlling for them, the attributes at issue must be accurately measurable if you are going to compare them in any scientifically acceptable way. And it turns out that the range of attributes that fulfill the conditions necessary for comparisons of this kind among human beings is smaller than you might think. One area of human experience where performance is rigorously measured in a quantitative way is sports, and two scientists at Penn State University recently did an intriguing study on human sprinters. This was a great subject for investigation, because it involved both a body system that has been of critical significance in human evolution and a complex mechanical lever arrangement in which potentially critical variables can be accurately measured. It has long been known that, compared to most of us, sprinters tend to have a larger proportion of “fast-twitch” fibers in their leg muscles. These muscle fibers contract more rapidly, but fatigue more quickly, than do “slow-twitch” fibers, which continuously burn oxygen and can keep repetitively contracting for a long time. The question that the Penn State researchers...

Share