Intergroup bias influences third-party punishment and compensation: In-group relationships attenuate altruistic punishment

Intergroup relationships can impact on a third party’s willingness to punish a violator, but few researchers have explored how intergroup relationships affect third-party compensation tendencies. We recruited 163 participants to observe a dictator game, and then choose either to punish the dictator or compensate the recipient, each of whom could be from the participant’s in-group or out-group. Third parties often chose not to punish in-group dictators and to compensate both in-group victims and out-group victims. When out-group members transgressed against the in-group, participants punished these out-group members just as often as they compensated the in-group recipients, although they punished out-group dictators more harshly than others overall. However, when both proposer and recipient came from the out-group, participants often did not intervene. We also found that third-party punishment and compensation were related to individual differences in participants’ trait empathy and Machiavellianism. Our findings shed light on the modulating effect of intergroup relationships on third-party altruistic decisions.