"At 74, Chagnon may be this country’s best-known living anthropologist; he is certainly its most maligned. His monograph, “Yanomamö: The Fierce People,” which has sold nearly a million copies since it was first published in 1968, established him as a serious scientist in the swashbuckling mode — In turning the Yanomami into the world’s most famous “unacculturated” tribe, Chagnon also turned the romantic image of the “noble savage” on its head. Far from living in harmony with one another, the tribe engaged in frequent chest-pounding duels and deadly inter-village raids; violence or threat of violence dominated social life. The Yanomami,...