"The mind is much more like a muscle than we've ever realized," says James Flynn, a social scientist at the University of Otago in New Zealand and author of 'What is Intelligence?' (Cambridge; $22). "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 is the same lesson learned from the Asian-American success story: I.Q. measures not just the quality of a person's mind but the quality of the world that person lives in.
When an I.Q. test is created, it is calibrated or "normed" so that the test-takers in the fiftieth percentile--those exactly at the median--are assigned a score of 100.
The Black and White Differences
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 father by black American G.I.s in post-war 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 black and white gap in the United States differs dramatically by age. Flynn 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.
The 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. The average I.Q. of first-grade students in schools that blacks attend is 95, which means that "kids who want to be above average don't have to aim as high."
The Asian-American Success Story; may confuse causes and effects
Is this success story a question of whether Asians have a genetic advantage in I.Q.?
In a 1975 study in San Francisco's Chinatown using something called the Lorge-Thorndike Intelligence Test, the Chinese-Americans produced high I.Q.s. However, this test was normalized in the nineteen fifties and would have been a piece of cake for children in the nineteen-seventies. When the Chinese-American scores were reassessed using up-to-date intelligence metrics, Flynn found, they came in at 97 verbal and 100 nonverbal--slightly lower I.Q.s than white Americans.
The Asian-American success story is based upon children not succeeding because of higher I.Q.s but despite their lower I.Q.s: the Asians were overachievers. Among whites, virtually everyone who joins the ranks of the managerial, professional and technical occupations has an I.Q. of 97 or above. Among Chinese-Americans, that threshold is 90. A Chinese-American with an I.Q. of 90, it would appear, does as much with it as a white American with an I.Q. of 97.
There should be no great mystery about Asian achievement. It has to do with hard work and dedication to higher education, and belonging to a culture that stresses professional success. Then success breeds success. The children of that first successful wave of Asian-Americans really did have I.Q.s that were higher than everyone else's--coming in somewhere around 103. Having worked their way into the upper reaches of the occupational scale, and taken note of how much the professional value abstract thinking, Asian-American parents have evidently made sure that their own children wore scientific spectacles.
Source: None of the Above; What I.Q. doesn't tell you about race. by Malcolm Gladwell in The New Yorker, December 17, 2007