ArgumentEvolutionary psychologists argue that because humans are biological creatures, cultural explanations must include biology. They thus offer to unify the natural and social sciences. Evolutionary psychologists rely on a specific history of cultural anthropology, particularly the work of Alfred Kroeber to make this point. A close examination of the history of cultural anthropology reveals that Kroeber acknowledged that humans were biological and culture had a biological foundation; however, he argued that we should treat culture as autonomous because that would bring benefits to the biological sciences as well as the human sciences. Hence, the historical caricature of his work by evolutionary psychology fails. The paper concludes that cultural anthropologists were successful in creating their discipline, at least in part, because they argued by pragmatic definition. Evolutionary psychology, on the other hand, offers an essentialist definition of “culture” and thus offers a much less promising vision of interdisciplinary collaboration.