aTypical Joe: a gay New Yorker living in the rural South

Tuesday, December 11, 2007

Gladwell takes on the I.Q. fundamentalists

In What I.Q. doesn’t tell you about race Malcolm Gladwell looks at the work of James Flynn, a social scientist at the University of Otago in New Zealand to convincingly refute the arguments of the “I.Q. fundamentalists.”

To the I.Q. fundamentalist, two things are beyond dispute: first, that I.Q. tests measure some hard and identifiable trait that predicts the quality of our thinking; and, second, that this trait is stable—that is, it is determined by our genes and largely impervious to environmental influences.

Not so says Flynn:

The best way to understand why I.Q.s rise, Flynn argues, is to look at one of the most widely used I.Q. tests, the so-called WISC (for Wechsler Intelligence Scale for Children). The WISC is composed of ten subtests, each of which measures a different aspect of I.Q. Flynn points out that scores in some of the categories-those measuring general knowledge, say, or vocabulary or the ability to do basic arithmetic-have risen only modestly over time. The big gains on the WISC are largely in the category known as “similarities,” where you get questions such as “In what way are ‘dogs’ and ‘rabbits’ alike?” Today, we tend to give what, for the purposes of I.Q. tests, is the right answer: dogs and rabbits are both mammals. A nineteenth-century American would have said that “you use dogs to hunt rabbits.” [...]

The psychologist Michael Cole and some colleagues once gave members of the Kpelle tribe, in Liberia, a version of the WISC similarities test: they took a basket of food, tools, containers, and clothing and asked the tribesmen to sort them into appropriate categories. To the frustration of the researchers, the Kpelle chose functional pairings. They put a potato and a knife together because a knife is used to cut a potato. “A wise man could only do such-and-such,” they explained. Finally, the researchers asked, “How would a fool do it?” The tribesmen immediately re-sorted the items into the “right” categories. It can be argued that taxonomical categories are a developmental improvement—that is, that the Kpelle would be more likely to advance, technologically and scientifically, if they started to see the world that way. But to label them less intelligent than Westerners, on the basis of their performance on that test, is merely to state that they have different cognitive preferences and habits. And if I.Q. varies with habits of mind, which can be adopted or discarded in a generation, what, exactly, is all the fuss about?

Exercise matters:

Flynn then talked about what we’ve learned from studies of adoption and mixed-race children - and that evidence didn’t fit a genetic model, either. If I.Q. is innate, it shouldn’t make a difference whether it’s a mixed-race child’s mother or father who is black. But it does: children with a white mother and a black father have an eight-point I.Q. advantage over those with a black mother and a white father. And it shouldn’t make much of a difference where a mixed-race child is born. But, again, it does: the children fathered by black American G.I.s in postwar Germany and brought up by their German mothers have the same I.Q.s as the children of white American G.I.s and German mothers.

The difference, in that case, was not the fact of the children’s blackness, as a fundamentalist would say. It was the fact of their Germanness - of their being brought up in a different culture, under different circumstances. “The mind is much more like a muscle than we’ve ever realized,” Flynn said. “It needs to get cognitive exercise. It’s not some piece of clay on which you put an indelible mark.” The lesson to be drawn from black and white differences was the same as the lesson from the Netherlands years ago: I.Q. measures not just the quality of a person’s mind but the quality of the world that person lives in.

When you finish Gladwell’s piece, check out Richard E. Nisbett’s OpEd from Saturday’s NYTimes, All Brains Are the Same Color:

The hereditarians begin with the assertion that 60 percent to 80 percent of variation in I.Q. is genetically determined. However, most estimates of heritability have been based almost exclusively on studies of middle-class groups. For the poor, a group that includes a substantial proportion of minorities, heritability of I.Q. is very low, in the range of 10 percent to 20 percent, according to recent research by Eric Turkheimer at the University of Virginia. This means that for the poor, improvements in environment have great potential to bring about increases in I.Q.

Comments Gladwell: “It’s very persuasive. And it would be interesting to see what, if anything, die-hard hereditarians like Charles Murray have to say in response.”

I’ll be watching for that response too.