Yanomami men who were killers had more wives and children than men who were not. Was the men’s aggression the main reason for their greater reproductive success? Chagnon suggested that the question deserved serious consideration. “Violence,” he speculated, “may be the principal driving force behind the evolution of culture.” The article was seized on by the press, including two newspapers in Brazil, where illegal gold miners had begun invading Yanomami lands. The Brazilian Anthropological Association warned that Chagnon’s “dubious scientific conclusions” could have terrible political consequences. . . .
Scientists have since endorsed Chagnon’s Science article. “It shouldn’t be a shocking finding,” Steven Pinker, the Harvard evolutionary psychologist who cites the paper in his book, “The Better Angels of Our Nature: Why Violence Has Declined,” told me. “As a pattern in history, it’s well documented.” Pinker said that he was troubled by the notion that social scientists should suppress unflattering information about their subjects because it could be exploited by others. “This whole tactic is a terrible mistake: always putting your moral action in jeopardy of empirical findings,” he told me. “Once you have the equation that the Yanomami are nonviolent and deserve to be protected, the converse is that if they are violent they don’t deserve to be protected.”