Has Black-White IQ gap narrowed?
Unsettled Scores: Has the Black-White IQ Gap Narrowed?
By Marina Krakovsky
February 2007 Scientific American http://www.sciam.com/issue.cfm
This much is uncontested: for most of the 20th century, blacks worldwide have scored, on average, 15 points lower on most IQ tests than have whites.
What scientists cannot agree on is why. Most attribute the gap to differences in education, health and other environmental influences. Hereditarians, on the other hand, view the black-white difference as largely genetic in origin. They note, among other indirect evidence, that the disparity persists across time and around the world – a permanence that is crucial to the debate over what explains group differences.
“If black-white differences converged – if there wasn’t this whopping big difference everywhere – there’d be no debate left,” says J. Philippe Rushton, a psychologist at theUniversity of Western Ontario and an outspoken hereditarian.
So it was big news when William T. Dickens and James R. Flynn published a paper in Psychological Science in October 2006 concluding that African-Americans have greatly reduced the racial IQ gap. Drawing on their analysis of four different IQ tests taken between 1972 and 2002, including the Stanford-Binet and the Armed Forces Qualification Test, the researchers say that blacks in the U.S. have gained four to seven IQ points on non-Hispanic whites, thus closing a quarter to half the gap.
To Dickens and Flynn, the implications are obvious. “The gap isn’t fixed in the stars,” says Flynn, a professor of political studies at the University of Otago in Dunedin , New Zealand , who is best known for his observations of the across-the-board IQ gains over time – evidence that environmental factors strongly drive scores. Dickens, a senior fellow in economic studies at the Brookings Institution, adds that future progress toward equal opportunity should continue to reduce the disparity.
But the evidence does not justify such optimism, says Rushton, who calls himself a race realist. When Rushton peer-reviewed the study, he argued for its rejection on the grounds that the data were cherry-picked, because it ignored at least four IQ tests whose results showed either no black gains or even a slight decline. In the end, he published a forceful commentary on the study, coauthored with the eminent (and controversial) psychologist Arthur Jensen of the University of California , Berkeley .
Dickens and Flynn rebutted, stating that they had excluded samples that were not representative of the U.S. population. For example, in one sample one group had more education than the race it represented, and it was clear which race that was. Dickens believes most IQ test publishers simply do not try to re-standardize their tests using nationally representative samples, making it hard for researchers to draw definitive inferences.
Linda Gottfredson, an education professor at the University of Delaware , points to a more serious question in the findings. If black IQ is rising, and if IQ is the best predictor of academic achievement, one would expect a similar rise in standardized achievement tests. Yet, she notes, most studies show no such gain. For instance, Charles Murray, a scholar at the conservative think tank American Enterprise Institute and author of the controversial 1994 best-seller The Bell Curve, published a report on black achievement in the December 2006 issue of the journal Intelligence; he concludes that although blacks started closing the school achievement gap during the 20th century, progress stopped for people born since the mid-1970s.
Dickens explains these discrepancies in part through different ways of looking at the same data. “No one doubts that there is an achievement gap,” he says. “The question is whether it has narrowed, and the answer is “yes,” although the gains have not been equal on all measures.
Gottfredson also points to a troublesome trend in the 30-year data that Dickens and Flynn used – namely, at each successive age, the black-white gap steadily increases. “All these data are interpreted as a slam dunk for environmental explanations, when they’re at least as consistent with genetic ones,” she says, adding that the effects of family environment tend to wash out with age. In the Dickens and Flynn model, on the other hand, an impoverished family environment actually creates greater disadvantages with age. For example, Dickens explains, “it’s much less of a problem for a four- or five-year old to have a high school dropout for a mother than a 16-year-old,” because poorly educated parents cannot help with advanced schoolwork.
If black progress has stalled, demographic changes may be to blame. Whereas high-IQ women of all races have lower birth rates, the birth rates of high-IQ black women in particular have “gone through the floor,” says Murray – leaving a shortage of both the best genes and the best family environments for the next generation. He adds, that even if it were possible to answer the genetic question once and for all, as he believes today’s DNA testing can help to do, most scientists would shy away from such research for political reasons.
Because genes interact with the environment, some researchers think the question of genetic differences by race is pointless. “What does that mean?” asks Eric Turkheimer, a University of Virginia psychologist who has explored poverty’s effect on realizing an individual’s genetic potential. What Rushton and Jensen must be arguing, he says, “is that a gap will remain under any environmental influence. And how can you possibly know that? All you can show is its been very frustrating to reduce.
- HiFor years I have noted that in South Africa, after WWII, during the norming of the Wechler-Bellevue, it became clear that Afrikaans-speaking South Africans had IQ's two standard deviations off the White South African, English Speaking mean, in the same way Black people did, and perhaps do. Urbanisation, and the advent of TV in 1973 changed all of that, and the Afrikaners caught up without changing their genes, just their exposure to the modern world, education, nutrition and other factors. The original news of the difference meant that the test makers in South Africa released the Wechsler, which remained in use for years, without a statistical manual, as the embarrassment for the ruling National Party in 1948 and into the '50's was just too ironic given their introduction of apartheid. I have made the point repeatedly here across the years that Black children are now entering the South African private schools, and previously white-only government schools, and clearly are inching forward in the IQ and level of education stakes. The gap narrowed for the unsophisticated Afrikaners, and for the Blacks now exposed to equal opportunity, one expects the same. Its not IQ, its what IQ tests MEASURE that is the problem, and we know that the concepts are Western. David Wechsler wrote in 1944 that he defined intelligence, not IQ, as the capacity to think rationally, act with purpose and deal effectively with the environment, not the Western environment, but the environment that produces the social pressures that tie the cortical knots, to quote Vygotsky. A shepherd who keeps leopards away and cannot count his 400 sheep, but knows them by name, colour and size, probably has a herd boy IQ that would leave most researchers alone, cold, with dead sheep and live leopards all over the shop. Bishop Desmond Tutu came from illiterate parents, and won a nobel prize. A patient I saw, the fifth generation of rabbinical geniuses, had an IQ of 60 on our Wechslers, but could argue the creation of angels and cherubs from twenty different, novel, premises. I think the debate on IQ is interesting but crap. 80% or so of Jewish refugees arriving at Ellis Island and tested on the Stanford Binet were shown to be retarded (see Gould). The researchers concluded that Europe was dumping its rubbish on America. Many of them were my relatives, and most went on to money and fame in various pursuits. IQ predicts things for Westerners, not for the rest of us. My brother in law has an IQ of 90 and an MBA, as he couldnt finish school, but spent 10 years in business and they let him in the course. He achieved his degree cum laude. The black man who taught me cross-cultural sensitivity came from nothing, in the townships, achieved his degrees at Harvard, and then went on to staff his law firm with black lawyers. The black middle and upper classes are emerging in South Africa well beyond their 2nd percentile ranking, and thousands are entering university, outgrowing the social knots that bound them under apartheid. Thats affirmative.Roy Sugarman.