For most of the history of this country, differences between the black and the white population--whether in income, IQ, crime rates, or whatever--have been attributed to either race or racism. For much of the first half of the 20th century, these differences were attributed to race--that is, to an assumption that blacks just did not have it in their genes to do as well as white people. The tide began to turn in the second half of the 20th century, when the assumption developed that black-white differences were due to racism on the part of whites.

Three decades of my own research lead me to believe that neither of those explanations will stand up under scrutiny of the facts. As one small example, a study published last year indicated that most of the black alumni of Harvard were from either the West Indies or Africa, or were the children of West Indian or African immigrants. These people are the same race as American blacks, who greatly outnumber either or both.

If this disparity is not due to race, it is equally hard to explain by racism. To a racist, one black is pretty much the same as another. But, even if a racist somehow let his racism stop at the water's edge, how could he tell which student was the son or daughter of someone born in the West Indies or in Africa, especially since their American-born offspring probably do not even have a foreign accent?

What then could explain such large disparities in demographic "representation" among these three groups of blacks? Perhaps they have different patterns of behavior and different cultures and values behind their behavior...