Intergroup Aggression in Chimpanzees and War in Nomadic Hunter-gatherers: Evaluating the Chimpanzee Model
Overview
Authors
Affiliations
Chimpanzee and hunter-gatherer intergroup aggression differ in important ways, including humans having the ability to form peaceful relationships and alliances among groups. This paper nevertheless evaluates the hypothesis that intergroup aggression evolved according to the same functional principles in the two species-selection favoring a tendency to kill members of neighboring groups when killing could be carried out safely. According to this idea chimpanzees and humans are equally risk-averse when fighting. When self-sacrificial war practices are found in humans, therefore, they result from cultural systems of reward, punishment, and coercion rather than evolved adaptations to greater risk-taking. To test this "chimpanzee model," we review intergroup fighting in chimpanzees and nomadic hunter-gatherers living with other nomadic hunter-gatherers as neighbors. Whether humans have evolved specific psychological adaptations for war is unknown, but current evidence suggests that the chimpanzee model is an appropriate starting point for analyzing the biological and cultural evolution of warfare.
Perceived inequality and variability in the expression of parochial altruism.
Ross C, Pisor A Evol Hum Sci. 2025; 7:e3.
PMID: 39935444 PMC: 11810521. DOI: 10.1017/ehs.2024.43.
Prosocial preferences can escalate intergroup conflicts by countering selfish motivations to leave.
Snijder L, Gross J, Stallen M, De Dreu C Nat Commun. 2024; 15(1):9009.
PMID: 39424809 PMC: 11489402. DOI: 10.1038/s41467-024-53409-9.
Is Culture Learned? The Neglected Role of Evoking Events.
Hallam R Integr Psychol Behav Sci. 2024; 58(4):2034-2052.
PMID: 39138787 DOI: 10.1007/s12124-024-09865-5.
The evolution of democratic peace in animal societies.
Hunt K, Patel M, Croft D, Franks D, Green P, Thompson F Nat Commun. 2024; 15(1):6583.
PMID: 39097569 PMC: 11297998. DOI: 10.1038/s41467-024-50621-5.
Dyadic inter-group cooperation in shotgun hunting activities in a Congo Basin village.
Kandza V, Jang H, Kiabiya Ntamboudila F, Lew-Levy S, Boyette A Evol Hum Sci. 2024; 6:e22.
PMID: 38689891 PMC: 11058523. DOI: 10.1017/ehs.2024.14.