The social sciences offer many insights into the causes of the intense ethnic conflicts that characterize the close of the twentieth century, but they also create obstacles to understanding these baffling problems, contends H. D. Forbes in this important book. Forbes takes a critical look at the "contact hypothesis"--the assumption commonly held by social scientists that increased contact between different ethnic groups gives each group more accurate information about the other and thus reduces friction. By distinguishing aggregate from individual relations, Forbes suggests a way out of the...