In a paper to be published in the October issure of the journal Psychological Science, William Dickens and James Flynn show that the gap in measured cognitive ability between blacks and whites has narrowed by at least a quarter since 1972. The researchers analyzed nationally representative samples of blacks and whites on four different tests of cognitive ability. On all four tests, blacks show large gains relative to whites with results varying somewhat across the different tests. Pooling the results, the researchers find that blacks have gained an average of .18 IQ points a year on whites from 1972 to 2002 for a total gain of 5.4 IQ points. Further, blacks have gained on whites at all points in the distribution of ability, with gains being only modestly lower for those in the top 10 percent.
These gains in cognitive ability have come during a time when blacks have made notable progress towards social and economic equality in some areas and suggest the possibility that further progress will bring further IQ gains.