malcolm gladwell on iq December 16, 2007Posted by KG in books, race, reviews, science.
Tags: eric turkheimer, flynn effect, genetic, i.q., intelligence test, james flynn, malcolm gladwell, race, william saletan
gladwell reviews james flynn’s new book in the new yorker and opines on the recent i.q. debate at his blog…
One argument that Saletan never soaked his head in, however, was Flynn’s, because what Flynn discovered in his mailbox upsets the certainties upon which I.Q. fundamentalism rests. If whatever the thing is that I.Q. tests measure can jump so much in a generation, it can’t be all that immutable and it doesn’t look all that innate.
The very fact that average I.Q.s shift over time ought to create a “crisis of confidence,” Flynn writes in “What Is Intelligence?” (Cambridge; $22), his latest attempt to puzzle through the implications of his discovery. “How could such huge gains be intelligence gains? Either the children of today were far brighter than their parents or, at least in some circumstances, I.Q. tests were not good measures of intelligence.”
So who’s right? Turkkeimer would say, both sides are.
He used a very large data set–the National Collaborative Perinatal Project–and found that the relationship between socio-economic status and IQ was non-linear. Children moving from poverty to the middle class see their IQ’s jump: IQ at that end of the socio-economic scale is highly sensitive to environmental improvements. But the kinds of twins studies usually relied upon by IQ fundamentalists and that yield such high genetic effects, are much more likely to involve comparisons among middle and upper middle class environments–and that end of the scale, Turkheimer’s data suggests, environment doesn’t play a big role.
In other words, the lawyer who plays Mozart in the crib for his daughter, in order to raise her IQ, is wasting his time. But dramatically increasing the educational resources available to inner city kids makes a lot of sense.