With their tonsured heads, white faces, and striking cowls, the monkeys might vaguely resemble the Capuchin monks for whom they were named. How they act is something else entirely. They climb onto each other's shoulders four deep to frighten enemies. They test friendship by sticking their fingers up one another's noses. They often nurse--but sometimes kill--each other's offspring. They use sex as a means of communicating. And they negotiate a remarkably intricate network of alliances, simian politics, and social intrigue. Not monkish, perhaps, but as we see in this downright ethnographic...