Aggression

Abstract

Violence and aggression, far from being random or pathological, follow patterns that reflect the selection pressures our ancestors faced, and this chapter traces those patterns across both sexes and multiple social contexts. It contrasts male physical aggression, rooted in direct mating competition and sexual dimorphism, with female indirect aggression operating through reputation damage and social exclusion, showing how both strategies serve adaptive functions while carrying distinct costs. The chapter situates human violence within a comparative framework, drawing on chimpanzee coalition behaviour and cross-cultural homicide data to show that lethal aggression follows predictable patterns shaped by status competition, sexual jealousy, and resource scarcity. It then examines how individuals and groups regulate aggression through social hierarchies, exploring the distinction between dominance and prestige, the hawk-dove model, the Dark Triad, and the punishment of both free-riders and high cooperators. Finally, the chapter considers warfare and in-group loyalty as extensions of the same adaptive logic, connecting individual aggression to collective violence.