Intergroup retaliation and intra-group praise gain: The effect of expected cooperation from the in-group on intergroup vicarious retribution

Intergroup vicarious retribution is the phenomenon whereby, after an out-group member attacks an in-group member, a member of the victim's group retaliates against a member of the perpetrator's group. This study examined the effect of expected cooperation from the in-group on intergroup vicarious retribution through intra-group reputation based on praise gain and exclusion avoidance. In the experiment, we conducted a one-on-one match in which, after participants learned that an out-group member (as the winner) had imposed a fine on an in-group member (as the loser) in a previous round, winning participants were allowed to impose an arbitrary fine on the other losing out-group member. As a result, participants imposed a larger fine on their out-group member opponent in retaliation when they were expected by in-group members to cooperate than when such cooperation was not expected. Furthermore, participants regarded a fine as intra-group cooperation. Since a path analysis revealed a mediating effect of praise gain, but no mediating effect of exclusion avoidance, expected cooperation from in-group members facilitated vicarious retribution because those involved in retribution sought praise from other in-group members. These findings suggest that the intra-group reputation dynamics of expected cooperation and praise gain escalate intergroup conflict.