When Napoleon Chagnon arrived in Venezuela's Amazon region in 1964 to study the Yanomam̲ Indians, one of the last large tribal groups still living in isolation, he discovered a remarkably violent society. Men who killed others had the most wives and offspring, their violence possibly giving them an evolutionary advantage. The prime reasons for violence, Chagnon found, were to avenge deaths and abduct women. When Chagnon began publishing his observations, some cultural anthropologists who could not accept an evolutionary basis for human behavior refused to believe them. A scathing attack-which was quickly disproven-accused him of starting a measles epidemic among the Yanomam̲, and the American Anthropological Association condemned him, only to rescind its condemnation after a vote by the membership. Thus Chagnon became perhaps the most famous American anthropologist since Margaret Mead-and the most controversial. In Noble Savages, Chagnon describes his seminal fieldwork-during which he lived among the Yanomam̲, was threatened by tyrannical headmen, and experienced an uncomfortably close encounter with a jaguar-taking readers inside Yanomam̲ villages to glimpse the kind of life our distant ancestors may have lived thousands of years ago. And he forcefully indicts his discipline of cultural anthropology, accusing it of having traded its scientific mission for political activism.