Behavior: Studying the American Tribe

When two well-dressed strangers turned up at a sleek apartment building on Chicago's Gold Coast, the doorman called the cops. The men explained they were anthropologists from the University of Chicago, anxious to study rich families. "The policeman couldn't believe it," said one of the men. "He looked first for my Encyclopaedia Britannica, then for my vacuum cleaner and then asked what was the gimmick."

The gimmick is that anthropologists, after decades of following Margaret Mead to Samoa and Bronislaw Malinowski to the Trobriand Islands, have staked out new territory—the nonexotic cities and...