There is an oft-voiced proposition within evolutionary psychology that over the course of evolutionary time, natural selection favored human males who have killed over those men who have not. The implication is that killing has been favorably selected as a fitness enhancing strategy. Interestingly, the impe-tus for this proposition in large part stems from one particular article on the tribal Yanomamö people of Brazil and Venezuela published in 1988. In this arti-cle, Chagnon (1988) reports that Yanomamö men who have participated in a killing out-reproduced their same-aged peers. If a Yanomamö man participates in a killing, he must undergo a purification ritual and henceforth wears the cultural label unokai. In a series of publications, Chagnon (1990: 95, 1992a: 205, 1992b: 239-240; see also Chagnon, 2010) reiterated that unokais average more than two-and-half times the number of wives and more than three times the number of offspring as non-unokais of the same age. Pinker (2002: 116) concludes that "if that payoff was typical of the pre-state societies in which humans evolved, the strategic use of violence would have been selected over evolutionary time." A careful re-examination of the Yanomamö unokai findings and the infer-ences that have been drawn from them are important because they have been broadcast far-and-wide and have been uncritically accepted within evolutionary psychology and other fields. For example, Buss discusses the unokai reproduc-tive success findings in Evolutionary Psychology (1999) and again in The Mur-derer Next Door (2005: 35): "Humans have evolved powerful psychological adaptations that impel us to murder as a means for solving specific problems we encounter during the evolutionary battles for survival and reproduction." Harris relates the killers-have-more-offspring finding in The Nurture Assumption. In U.S. News and World Report, a journalist proposed that Chagnon's study "lends new credence" to the idea that "war arises from individuals struggling for reproductive success" (Allman, 1988: 57). Pinker reiterates the findings in How the Mind Works (1997) and again in The Blank Slate (2002).