Jim Holt:

Success in life depends on intelligence, which is measured by I.Q. tests. Intelligence is mostly a matter of heredity, as we know from studies of identical twins reared apart. Since I.Q. differences between individuals are mainly genetic, the same must be true for I.Q. differences between groups. So the I.Q. ranking of racial/ethnic groups — Ashkenazi Jews on top, followed by East Asians, whites in general, and then blacks — is fixed by nature, not culture. Social programs that seek to raise I.Q. are bound to be futile. Cognitive inequalities, being written in the genes, are here to stay, and so are the social inequalities that arise from them.
What I have just summarized, with only a hint of caricature, is the hereditarian view of intelligence. This is the view endorsed, for instance, by Richard J. Herrnstein and Charles Murray in “The Bell Curve” (1994), and by Arthur R. Jensen in “The g Factor” (1998). Although hereditarianism has been widely denounced as racism wrapped in pseudoscience, these books drew on a large body of research and were carefully reasoned. Critics often found it easier to impugn the authors’ motives than to refute their conclusions.

Intelligence and How to Get It.