Almost all of the themes contained in E.O.Wilson's sociobiological writing on war and human aggression were prefigured in Anglo-American bio-social discourse, c. 1880–1919. Instinct theory – stemming from animal psychology and the genetics revolution – encouraged the belief that pugnacity had been programmed into the ancient part of the human brain as a result of evolutionary pressures dating from prehistory. War was seen to be instinct-driven, and genocidal fighting postulated as a eugenic force in early human evolution. War was explained (...) in distinctly modern sociobiological terms as adaptive behaviour springing from territorial urges, crowding, competition for resources and reproductive advantage, ethnocentrism and pseudo-speciation. (shrink)