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. 2022 May 23;377(1851):20210134.
doi: 10.1098/rstb.2021.0134. Epub 2022 Apr 4.

Intergroup conflict: origins, dynamics and consequences across taxa

Carsten K W De Dreu  1   2 , Zegni Triki  3
Affiliations

Intergroup conflict: origins, dynamics and consequences across taxa

Carsten K W De Dreu et al. Philos Trans R Soc Lond B Biol Sci. .

Abstract

Although uniquely destructive and wasteful, intergroup conflict and warfare are not confined to humans. They are seen across a range of group-living species, from social insects, fishes and birds to mammals, including nonhuman primates. With its unique collection of theory, research and review contributions from biology, anthropology and economics, this theme issue provides novel insights into intergroup conflict across taxa. Here, we introduce and organize this theme issue on the origins and consequences of intergroup conflict. We provide a coherent framework by modelling intergroup conflicts as multi-level games of strategy in which individuals within groups cooperate to compete with (individuals in) other groups for scarce resources, such as territory, food, mating opportunities, power and influence. Within this framework, we identify cross-species mechanisms and consequences of (participating in) intergroup conflict. We conclude by highlighting crosscutting innovations in the study of intergroup conflict set forth by individual contributions. These include, among others, insights on how within-group heterogeneities and leadership relate to group conflict, how intergroup conflict shapes social organization and how climate change and environmental degradation transition intergroup relations from peaceful coexistence to violent conflict. This article is part of the theme issue 'Intergroup conflict across taxa'.

Keywords: contests; cooperation; fitness; intergroup conflict; natural selection; social species.

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Conflict of interest statement

This theme issue was put together by the Guest Editor team under supervision from the journal's Editorial staff, following the Royal Society's ethical codes and best-practice guidelines. The Guest Editor team invited contributions and handled the review process. Individual Guest Editors were not involved in assessing papers where they had a personal, professional or financial conflict of interest with the authors or the research described. Independent reviewers assessed all papers. Invitation to contribute did not guarantee inclusion.

Figures

Figure 1.
Figure 1.
Violent intergroup conflict in humans. The burial at Wassenaar contains the remains of 12 people possibly murdered during an out-group raid on their settlement (approx. 3400 BP; reproduced with courtesy of Dr Louwe Kooijmans and Faculty of Archaeology, Leiden University).
Figure 2.
Figure 2.
Framework for analysing intergroup conflict. Mechanisms at the individual, group and environmental level of analysis producing the initiation, escalation and settlement of intergroup conflict, with conflict pay-offs for individuals and their groups. Recurrent intergroup conflict within and across species' generations has possible ultimate consequences on the individual, group and environmental level of analysis. (Online version in colour.)
Figure 3.
Figure 3.
Intergroup conflict as a mechanism in the evolution of group-living species. Populations or species may face intergroup conflict or not within and across generations (e.g. comparing populations A1, A2 and B1 to population B2), and when intergroup conflict occurs, it may be more or less frequent (e.g. comparing populations A1 and A2) and with strong versus weak proximate consequences (e.g. comparing populations A2 and B1). Populations can refer to an entire species or to a species with lineages living in distinct ecological niches. The frequency and impact of intergroup conflict within and across generations shape ultimate consequences in terms of survival and fitness and how groups are socially organized in terms of size, cohesiveness and horizontal and vertical task specializations. (Online version in colour.)
See this image and copyright information in PMC

References

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