Intergroup conflict is a major evolutionary force shaping animal and human societies. Males
and females should, on average, experience different costs and benefits for participating in …

Coalitionary support in agonistic interactions represents cooperation because intervening in
a fight is potentially costly to the donor of support but benefits the recipient. Here, we first …

Via the current model on the evolutionary ecology of female social relationships, Sterck et
al.(1997) argue that ecological conditions determine how competition over food resources …

The Primate Origins of Human Nature (Volume 3 in The Foundations of Human Biology
series) blends several elements from evolutionary biology as applied to primate behavioral …

Male chimpanzees, Pan troglodytes, cooperate to defend a community range within which
resident females range in smaller core areas. There has been debate over exactly what …

AH Harcourt, a well-known professor of anthropology at the University of California, has
published papers on gorillas since 1978 and KJ Stewart has worked with him since 1987 …

Group members do not always act cohesively when facing extra-group rivals. When benefits
such as group-defence are not monopolizable, it poses an economics problem: who should …

Objectives Although conflicts between groups over valuable resources are common in the
animal kingdom, an individual's strategy toward out‐group individuals may differ according …

Male chimpanzees, Pan troglodytes, defend group territories, and sometimes injure or kill
members of other groups. To test which factors best predict the occurrence and outcomes of …

P RIMATE SOCIALITY has many faces. Some callitrichines form small groups with just one
reproducing female and others who help care for her young. Hamadryas baboons (Papio …