May 2007 —

In 2001 William Dickens and James Flynn proposed a model of cognitive ability that explains how large IQ gains, such as those observed in the United States and other countries over the 20th century, are possible despite the substantial roll played by genes in explaining differences among people within the same social group.
That model predicts that improvements in the environments of African Americans should have resulted in a decline in the white-black IQ gap and in 2006 Dickens and Flynn presented evidence that such a decline has indeed taken place. In an article forthcoming in The New Palgrave Dictionary of Economics, Dickens explains his views on cognitive ability. Most recently Dickens presented a paper on a new theory of general intelligence at the April 2007 meetings of the American Education Research Association meetings in Chicago.