Editors ' Summary James Boone, in this chapter, develops a model for the origin of complex and hierarchical societies and competitive warfare which takes as its fundamental premise that social behavior of groups is best explained as the aggregate consequence of individual behavior strategies. For example, Boone argues that warfare in complex societies is really the result of individual adaptive strategies to maximise political and economic position or control over resources. This is in marked contrast to the cultural evolutionary theories of, for example, Karris (1979) and White (1975) which view societies and cultures as functionally integrated, self-maintaining systems, and warfare as a population control mechanism ( Divale and Harris 1976 ). Boone then analyzes historical data from France and the Iberian Peninsula and shows that they better fit the predictions of his model, which is compatible with Darwinian theory, than those developed by cultural ecologists, which are not.