Culture and Society.(Us and Them, David Berreby's new book)(Book review)

Us and Them, by David Berreby (Little, Brown; $26.95). Berreby's aim is to demonstrate how greatly what he calls our "tribal" nature--the tendency to judge others according to categories, such as Muslims, lawyers, whites--governs our lives. Drawing on such diverse disciplines as psychology, genetics, and social neuroscience, he demonstrates both the frequent instability of such categories--for instance, the idea of Type A and Type B personalities, once influential in psychology, has been discredited--and their power. Berreby's thesis is often clouded by a superabundance of examples, but it is nonetheless a stimulating tour of a fascinating topic. He is particularly trenchant on the subject of race, a category more or less abandoned by geneticists but inexorable at a social level. He notes, "Racial and ethnic groups are real the way money is real--because people believe they are and act on their beliefs."

Cosmopolitanism, by Kwame Anthony Appiah (Norton; $23.95). Appiah, a Princeton philosophy professor, articulates a precise yet flexible ethical manifesto for a world characterized by heretofore unthinkable interconnection but riven by escalating fractiousness. Drawing on his Ghanaian roots and on examples from philosophy and literature, he attempts to steer a course between the extremes of liberal universalism, with its tendency to impose our values on others, and cultural relativism, with its implicit conviction that gulfs in understanding cannot be bridged. Cosmopolitanism, in Appiah's formulation, balances our "obligations to others" with the "value not just of human life but of particular human lives"--what he calls "universality plus difference." Appiah remains skeptical of simple maxims for ethical behavior--like the Golden Rule, whose failings as a moral precept he swiftly ...