One of the ongoing debates about IQ tests (besides whether they measure anything meaningful) is to what extent race affects scores. As Malcolm Gladwell explains in a review of a new book by James Flynn, for whom the Flynn Effect is named, IQ scores seem from the available data to be influenced more by nurture than nature.
Our great-grandparents may have been perfectly intelligent. But they would have done poorly on I.Q. tests because they did not participate in the twentieth century's great cognitive revolution, in which we learned to sort experience according to a new set of abstract categories. In Flynn's phrase, we have now had to put on "scientific spectacles," which enable us to make sense of the WISC questions about similarities. To say that Dutch I.Q. scores rose substantially between 1952 and 1982 was another way of saying that the Netherlands in 1982 was, in at least certain respects, much more cognitively demanding than the Netherlands in 1952. An I.Q., in other words, measures not so much how smart we are as how modern we are.
That last line is a pretty insightful way to think about IQ tests. On his blog, Gladwell references a recent article by Richard Nesbitt, who closes it with:
Most important, we know that interventions at every age from infancy to college can reduce racial gaps in both I.Q. and academic achievement, sometimes by substantial amounts in surprisingly little time. This mutability is further evidence that the I.Q. difference has environmental, not genetic, causes. And it should encourage us, as a society, to see that all children receive ample opportunity to develop their minds.