Group cooperation, carrying-capacity stress, and intergroup conflict

Abstract

Peaceful intergroup relations deteriorate when individuals engage in parochial

cooperation and parochial competition. To understand when and why intergroup

relations change from peaceful to violent, we present a theoretical framework

mapping out the different interdependence structures between groups. According to this framework, cooperation can lead to group expansion and ultimately to carrying-capacity stress. In such cases of endogenously created carryingcapacity stress, intergroup relations are more likely to become negatively interdependent, and parochial competition can emerge as a response. We discuss the cognitive, neural, and hormonal building blocks of parochial cooperation, and conclude that conflict between groups can be the inadvertent consequence of human preparedness – biological and cultural – to solve cooperation problems within groups.