Monday, October 22, 2007

The Bell Curve Again

It keeps coming back: every few years somebody revives the argument about whether there are significant differences in intelligence across races. This time it’s James Watson, the Nobel Prize-winning co-discoverer of DNA, who has ignited the usual firestorm by saying that Africans are less intelligent than the rest of us.
Or something like that. Here’s the crux of what he actually said in an interview with the Sunday Times Magazine:
“...all our social policies are based on the fact that their intelligence is the same as ours - whereas all the testing says not really.”

...and then:
“There is no firm reason to anticipate that the intellectual capacities of peoples geographically separated in their evolution should prove to have evolved identically. Our wanting to reserve equal powers of reason as some universal heritage of humanity will not be enough to make it so.”
The reaction was fast: Watson was fired from his administrative position at Cold Spring Harbor Laboratory a couple of days after the interview, and a spokesman for a British human rights group said: “[Watson’s statement] amounts to fueling bigotry and we would like it to be looked at for grounds of legal complaint.”
At the same time, other people were accusing Watson’s critics of political correctness, suppression of free discussion, and a refusal to consider evidence which goes against orthodox notions. Do they have a point? Watson’s statement was an empirical claim, which presumably can be tested for its truth value. Should he lose his job, or even be prosecuted, because it makes a claim most of us are reluctant to admit could be true?
Not many of us are conversant with the relevant science, and it often seems to boil down to conflicting claims. “...geneticists, psychologists, neuroscientists and educationalists have rebutted [the claims of scientific racism] many times over,” said biologist Steven Rose in The New Statesman. Meanwhile, a respondent using the name Caledonia in a discussion on the Pharyngula science blog confidently states: “People who are actually familiar with the basics of psychometric testing also know that various ethnic subpopulations score differently on the scale of large groups. And yes, attempts have been made to account for these differences, and obvious things like SES and nutrition can't account for all of them.”
Who’s right? How are we to make sense of all this? Most of us find racist views repellent. We’d love to think that there’s no scientific basis for racist views. But is that just wishful thinking? What about that nagging voice that says that if we are really open-minded we have at least to consider evidence that things might not be as we’d wish? Well, a few random thoughts come to mind right away: No, people shouldn’t be prosecuted for offering unpopular opinions. They shouldn’t lose their jobs merely for making claims about matters of fact, even if those facts are unpalatable (and still in question). There is a whiff of censorship in the reaction to Watson’s statement. The reaction lends credence to those who claim that liberals enforce an orthodoxy of thought in the media and society at large.
But other random thoughts occur as well: Why do people keep bringing this up? What is the utility of a claim like this in the first place? If Watson (or Charles Murray of Bell Curve fame) is correct, the statistical distribution of intelligence (the infamous “bell curve”) for people of African descent is shifted to the left of the bell curve for people of European descent. In other words, the average intelligence of the first group is lower than that of the second. Well, my first observation is that the shift is fairly slight, no matter how you plot it: a whole lot of black people are still smarter than a whole lot of white people. But more importantly, the amount of information about any given individual conveyed by the bell curve is exactly zero. There is no way of telling where any given individual lies on that curve except to test that person individually. In other words, if we are treating people as individuals, which is what we should be doing as a matter of profound and unshakable principle in this country, the curve is useless. It is a curiosity at best.
So why are some people still doing research on this? There seems to be a fairly broad consensus in biology that the notion of race is not biologically significant. (See a good discussion of this at And the notion of intelligence is pretty fuzzy, too. The Mensa quiz doesn’t quite nail it, I’m afraid. There are different types of intelligence, and intelligence isn’t graven in stone even within one person’s lifetime. It seems to me that the idea of racial differences in intelligence presumes a firmer idea of both race and intelligence than is actually warranted.
But just for the sake of argument, let’s concede that the categories and the differences are real: my response is still, “So what?” Plain old waspy Americans like me are supposedly on average less intelligent than Asians or Ashkenazi Jews. Am I worried? No, as long as I’m hired, fired, stroked, chewed out, rewarded, punished, prosecuted, acquitted, scorned, respected, hated or loved on the basis of my behavior as an individual, and not on the basis of my membership in a group, whatever the statistics about that group. That, the insurance of equality before the law and institutional fairness to individuals, is the central problem, the central struggle of American society or any other society. The question of which group is more intelligent on average is simply and utterly irrelevant.
So while it’s wrong to try to censor science, there’s nothing wrong with questioning a research program. I’m just wondering why this particular research program still appeals to people.
An abashed James Watson apologized for his remarks a few days after the controversy broke, saying he was “mortified”. Here’s an interesting question: Why didn't he stick to his guns?

Sam Reaves

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