Shadow of conflict: How past conflict influences group cooperation and the use of punishment

Intergroup conflict profoundly affects the welfare of groups and can deteriorate intergroup relations long after is over. Here, we experimentally investigate how experience an influences ability to establish cooperation conflict. We induced by using a repeated attacker-defender game in which four are divided into two ‘attackers’ that invest resources take away from other participants role ‘defenders.’ After conflict, engaged public goods with peer-punishment, group members could benefit punish for their decisions. Previous did not significantly reduce compared control treatment However, when having experienced individuals punished free-riding during less harshly react punishment previous attackers, ultimately reducing welfare. This result reveals important boundary condition peer institutions. Peer able efficiently promote amid ‘shadow conflict.’ In third treatment, tested whether such ‘maladaptive’ patterns be mitigated hiding members’ roles subsequent provision game. find more identify each as (previous) attackers defenders maladaptive disappeared. Results suggest undermines past perpetrators’ legitimacy enforce norms. More generally, results reveal effectiveness institutions managing commons.