ArticleProceedings of the National Academy of Sciences of the United States of America2016
In-group defense, out-group aggression, and coordination failures in intergroup conflict.
Article in Proceedings of the National Academy of Sciences of the United States of America, 2016. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 33 papers.
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Who cites it
33 citing papers in PubMed, 120 citations in OpenAlex.
- Intentions poorly explain how and why people engage in offensive and defensive forms of violence.Proceedings of the National Academy of Sciences of the United States of America · 2026Article
- The psychology of offensive and defensive intergroup violence: Preregistered insights from 58 countries.Proceedings of the National Academy of Sciences of the United States of America · 2026Article
- How defense rhetoric escalates intergroup conflict.iScience · 2025Article
- Speech Repression and Threat Narratives in Politics: Social Goals and Cognitive Foundations.Annals of the New York Academy of Sciences · 2025Review
- Social play in African savannah elephants may inform selection against aggression.Current zoology · 2024Article
- Prosocial preferences can escalate intergroup conflicts by countering selfish motivations to leave.Nature communications · 2024Article
- Social bonding in groups of humans selectively increases inter-status information exchange and prefrontal neural synchronization.PLoS biology · 2024Article
- Leader-follower behavioural coordination and neural synchronization during intergroup conflict.Nature human behaviour · 2023Article
- Article
- Inter-brain neural mechanism underlying turn-based interaction under acute stress in women: a hyperscanning study using functional near-infrared spectroscopy.Social cognitive and affective neuroscience · 2022Article
- Intergroup conflict: origins, dynamics and consequences across taxa.Philosophical transactions of the Royal Society of London. Series B, Biological sciences · 2022Article
- Key individuals catalyse intergroup violence.Philosophical transactions of the Royal Society of London. Series B, Biological sciences · 2022Review
- Environmental stress increases out-group aggression and intergroup conflict in humans.Philosophical transactions of the Royal Society of London. Series B, Biological sciences · 2022Article
- Oxytocin has 'tend-and-defend' functionality in group conflict across social vertebrates.Philosophical transactions of the Royal Society of London. Series B, Biological sciences · 2022Review
- Exploring COVID-19 research credibility among Spanish scientists.Current psychology (New Brunswick, N.J.) · 2022Article
- Null results for the steal-framing effect on out-group aggression.Scientific reports · 2022Article
- Cognitive and neural bases of decision-making causing civilian casualties during intergroup conflict.Nature human behaviour · 2021Article
- National parochialism is ubiquitous across 42 nations around the world.Nature communications · 2021Article
- Article
- Political games of attack and defence.Philosophical transactions of the Royal Society of London. Series B, Biological sciences · 2021Review
Corrections and comments
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Authors and funding
7 authors at 4 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Intergroup conflict persists when and because individuals make costly contributions to their group's fighting capacity, but how groups organize contributions into effective collective action remains poorly understood. Here we distinguish between contributions aimed at subordinating out-groups (out-group aggression) from those aimed at defending the in-group against possible out-group aggression (in-group defense). We conducted two experiments in which three-person aggressor groups confronted three-person defender groups in a multiround contest game (n = 276; 92 aggressor-defender contests). Individuals received an endowment from which they could contribute to their group's fighting capacity. Contributions were always wasted, but when the aggressor group's fighting capacity exceeded that of the defender group, the aggressor group acquired the defender group's remaining resources (otherwise, individuals on both sides were left with the remainders of their endowment). In-group defense appeared stronger and better coordinated than out-group aggression, and defender groups survived roughly 70% of the attacks. This low success rate for aggressor groups mirrored that of group-hunting predators such as wolves and chimpanzees (n = 1,382 cases), hostile takeovers in industry (n = 1,637 cases), and interstate conflicts (n = 2,586). Furthermore, whereas peer punishment increased out-group aggression more than in-group defense without affecting success rates (Exp. 1), sequential (vs. simultaneous) decision-making increased coordination of collective action for out-group aggression, doubling the aggressor's success rate (Exp. 2). The relatively high success rate of in-group defense suggests evolutionary and cultural pressures may have favored capacities for cooperation and coordination when the group goal is to defend, rather than to expand, dominate, and exploit.
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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.