Primate Social Evolution

Primates display a remarkable diversity of types of social organization—a diversity that, according to the socioecological model of social evolution, is ultimately determined by ecological factors limiting female fitness and the number of matings limiting male fitness. The foremost ecological determinants of female sociality are the degree to which food resources are defendable, either alone or in a group, and the level of protection from predators gained from being part of a group. Further factors that have been proposed are the presence of infanticide, coalitions, and dominance hierarchies; general population density and habitat saturation; whether competition is mainly intra‐ or intergroup; and which sex disperses. Male sociality is instead mainly determined by the spatiotemporal spacing of mating opportunities with females. Some researchers have also proposed that cognitive abilities impose a limit on group size, since primate sociality demands competent navigation of social networks