Thursday, March 01, 2012
It's a few years old, but Malcolm Gladwell's review of James Flynn's None of the Above is worth reading and keeping in mind for the next time the subject of IQ and race comes up, as it has a few times in comments here in the past. The book calls into question the tidy assumptions some people like to make regarding race and IQ, by considering such matters as the method used to measure intelligence in individuals (i.e., tests that have to be "re-normed" periodically to account for cultural and technological change) and how analyses of the data are performed (e.g., whether two sample populations really are comparable; or whether some relevant, explanatory variable, such as age, might have been omitted from the analysis).
I'll excerpt a couple of clear cases, starting here with a striking example of how one's culture can affect how one answers test questions:
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?This problem isn't confined to distant tribes: Flynn famously observed that IQ, as measured by standardized tests, rises by 0.3 points per year. Gladwell restates this: "If an American born in the nineteen-thirties has an I.Q. of 100, the Flynn effect says that his children will have I.Q.s of 108, and his grandchildren I.Q.s of close to 120..." Extrapolating backwards, Gladwell notes that "[T]he average I.Q.s of the schoolchildren of 1900 [would be] around 70, which is to suggest, bizarrely, that a century ago the United States was populated largely by people who today would be considered mentally retarded." Clearly, there is some problem with the test.
Flynn also dispenses with a couple of common racial stereotypes perpetuated by people Gladwell aptly calls "IQ fundamentalists". For example, Flynn considers the question of whether there is a genetic or environmental reason for low IQ scores among American blacks relative to whites:
Flynn took a different approach. The black-white gap, he pointed out, differs dramatically by age. He noted that the tests we have for measuring the cognitive functioning of infants, though admittedly crude, show the races to be almost the same. By age four, the average black I.Q. is 95.4 -- only four and a half points behind the average white I.Q. Then the real gap emerges: from age four through twenty-four, blacks lose six-tenths of a point a year, until their scores settle at 83.4.Flynn considers other evidence, but this should serve to show how difficult it can be to correctly interpret differences in scores among demographic groups, even if questions about the measuring instrument are set aside for the sake of argument.
That steady decline, Flynn said, did not resemble the usual pattern of genetic influence. Instead, it was exactly what you would expect, given the disparate cognitive environments that whites and blacks encounter as they grow older. Black children are more likely to be raised in single-parent homes than are white children -- and single-parent homes are less cognitively complex than two-parent homes. ...
This is just a taste of how thorny a question it is to measure human intellectual potential, and its lessons are much more broadly applicable than as a hammer to use against the claims of racists: Even people who are not simply bigots eager to dress their foolishness up in the garb of science have accepted some of these scientific-sounding stereotypes. Furthermore, "scientific" fads occur among laymen in other disciplines, as well, when people who do not understand the complexities of a given area are tripped up by a combination of ignorance and misapplied common sense. After all, it isn't entirely unreasonable to conclude that a group that performs worse on a test than another group has less native ability -- but it's still not necessarily correct.
It may well be that most people in modern Western culture go about wearing what Flynn calls "scientific spectacles", but that plainly doesn't make everyone scientists.
3-3-12: Corrected a typo.