ABSTRACT
This chapter outlines some evolutionary ecological approaches to analyzing and explaining the formation of hierarchical social groups among humans. The group formation model assumes that the actors have the option of either joining and staying with a group or leaving it to live solitarily or with another group on more favorable terms. Vehrencamp has developed a model of optimal and equilibrium group structure based on the idea that "the opposing forces of competition and cooperation within most groups reach a stable equilibrium that determines both the optimal group size and the degree of bias". Competition over resources can be divided into two main categories: scrambles and contests. The classic game that captures contest competition over resources is Hawk—Dove. Hierarchical relations in human social systems result from a series of asymmetric compromises, which ultimately amount to transactions involving the two-way transfer of resources, rights, services, or other benefits.
