Untangling altruism and parochialism in human intergroup conflict

Author(s)
Robert Böhm, Luke Glowacki, Hannes Rusch, Isabel Thielmann
Abstract

Human intergroup conflict occurs on a scale unmatched in other mammals. Paradoxically, this capacity for war is closely linked to our exceptionally cooperative abilities. Models of "parochial altruism" describe how within-group cooperation and between-group competition may co-evolve, but it is unclear whether these models reflect human preference adaptation in real-world conflicts. Across five studies (total

N = 1,121), we develop and validate a psychometric toolkit to test the core assumptions and predictions of parochial altruism models in groups involved in real conflicts of varying intensities. Our measures clearly distinguish interindividual altruism from intergroup parochialism, outperform prior metrics in capturing social preferences related to intergroup conflict, and improve predictions of individuals' conflict contributions. Notably, we find that parochialism varies for different outgroups-an unanticipated result that challenges existing theoretical models. Our work provides new tools for studying individual- and group-level social preferences in intergroup relations and presents novel evidence to inform substantive theoretical improvement.

Organisation(s)
Department of Occupational, Economic and Social Psychology
External organisation(s)
Leopold-Franzens-Universität Innsbruck, Boston University, Maastricht University (UM), Max Planck Institute for the Study of Crime, Security and Law
Journal
Iscience
Volume
28
ISSN
2589-0042
DOI
https://doi.org/10.1016/j.isci.2025.113978
Publication date
12-2025
Peer reviewed
Yes
Austrian Fields of Science 2012
501021 Social psychology
Keywords
ASJC Scopus subject areas
General
Sustainable Development Goals
SDG 16 - Peace, Justice and Strong Institutions
Portal url
https://ucrisportal.univie.ac.at/en/publications/f5081ab0-439d-43e2-8677-d11fe2b7c961