Primate individuals use a variety of strategies in intergroup encounters, from aggression to
tolerance; however, recent focus on the evolution of either warfare or peace has come at the …

Play is one of the most difficult behaviors to quantify and for this reason, its study has had a
very rocky history. Social play is ephemeral, difficult to distinguish from the other so-called …

Reproductive inequality, or reproductive skew, drives natural selection, but has been difficult
to assess, particularly for males in species with promiscuous mating and slow life histories …

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 …

In social-living animals, interactions between groups are frequently agonistic, but they can
also be tolerant and even cooperative. Intergroup tolerance and cooperation are regarded …

Intergroup interactions in primates vary from nonagonistic to severely aggressive. Food
resources and fertile females cause intergroup aggression when groups defend resources …

Although many animals typically defend key resources from conspecifics during encounters,
tolerant encounters also occur frequently in some primate species. For example, African …

Intergroup competition is a widespread phenomenon across taxa and groups typically
compete over access to limited resources, such as food and mates. Such competition may …

Admixture appears increasingly ubiquitous in the evolutionary history of various taxa,
including humans. Such gene flow likely also occurred among our closest living relatives …

Highlights•Male bonobos rarely participated in coalitionary attacks against an
outgroup.•Male testosterone levels did not vary in relation to intergroup encounters.•Males …