Evolutionary anthropology has focused on the origins of war, or rather ethnocentricity, because it epitomizes the problem of group selection, and because war may itself have been the main agent of group selection. The neo-Darwinian synthesis in biology has explained how ethnocentricity might evolve by group selection, and the distinction between evoked culture and adopted culture, suggested by the emerging synthesis in evolutionary psychology, has explained how it might be transmitted. Ethnocentric mechanisms could have evolved by genetic selection in ancestral hominids, or through the interaction of genetic and cultural selection in modern humans, or both. The existence of similar behaviors in chimpanzees and the parallel development of early human societies around the globe are arguments for such inherited mechanisms. There may have been some adaptive breakthroughs in purely cultural evolution, but this process does not seem likely to produce long-term Darwinian adaptations because of the prolificity of cultural traits. Warfare may once have been major agent of group selection, but the rates of extinction among human groups are so slow as to render this improbable since the rise of state-level societies, whose warfare tends to become a cyclical balance-of-power situation. Perhaps the most serious implication of current evolutionary thought is that the individualistic model of culture common in the social sciences and humanities is outmoded, and should be replaced by a new model that recognizes the organismic nature of human societies.