Prosocial preferences can escalate intergroup conflicts by countering selfish motivations to leave

Nature Communications, vol. 15, pp. 9009

Abstract

When defending against hostile enemies, individual group members can benefit from others staying in the group and fighting. However, individuals themselves may be better off by leaving the group and avoiding the personal risks associated with fighting. While fleeing is indeed commonly observed, when and why defenders fight or flee remains poorly understood and is addressed here with three incentivized and preregistered experiments (total n = 602). In stylized attacker-defender contest games in which defenders could stay and fight or leave, we show that the less costly leaving is, the more likely individuals are to abandon their group. In addition, more risk-averse individuals are more likely to leave. Conversely, individuals more likely stay and fight when they have pro-social preferences and when fellow group members cannot leave. However, those who stay not always contribute fully to group defense, to some degree free-riding on the efforts of other group members. Nonetheless, staying increased intergroup conflict and its associated costs. When individuals meet hostile groups, they can choose whether to defend themselves or flee and leave others behind. Here, the authors show that pro-social preferences predict staying and defense, while leaving is predicted by concerns for personal costs and risk.

Authors 4

1. Luuk L. Snijder corresponding Aachen Social

   Leiden University

   Affiliation as printed

   Social, Economic and Organisational Psychology, Leiden University, Leiden, The Netherlands. l.snijder@fsw.leidenuniv.nl

   Social, Economic and Organisational Psychology, Leiden University, Leiden, The Netherlands

2. Jörg Gross

   University of Zurich

   Affiliation as printed

   Department of Psychology, University of Zurich, Zurich, Switzerland

3. Mirre Stallen Aachen Social

   Leiden University · Amsterdam University of Applied Sciences

   Affiliation as printed

   Poverty Interventions, Center for Applied Research on Social Sciences and Law, Amsterdam University of Applied Sciences, Amsterdam, The Netherlands

   Social, Economic and Organisational Psychology, Leiden University, Leiden, The Netherlands

4. Carsten K. W. De Dreu

   University of Groningen · German Primate Center

   Affiliation as printed

   Behavioral Ecology and Sociobiology Unit, German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany

   Faculty of Behavioral and Social Sciences, University of Groningen, Groningen, The Netherlands

   Faculty of Economics and Business, University of Groningen, Groningen, The Netherlands