Social value orientation moderates ingroup love but not outgroup hate in competitive intergroup conflict

In intergroup conflict, individual cooperation may be directed at strengthening the ingroup, thus undermining the effectiveness and sustainability of the competing outgroup. Reversely, cooperation directed towards the competing outgroup indirectly undermines the viability of the ingroup and is often seen by ingroup members as disloyal, non-cooperative behavior. Using the Intergroup Prisoner’s Dilemma—Maximizing Differences Game to model intergroup conflict, the experiment reported here shows that compared to individuals with a chronic pro-self orientation, those with a chronic prosocial orientation display stronger ingroup trust and ingroup love—they self-sacrifice to benefit their ingroup—but not more or less outgroup distrust and outgroup hate. Furthermore, in this situation pro-social individuals were driven more by ingroup fairness considerations when contributing to their ingroup. Path analyses suggest that effects of social value orientation on ingroup love are mediated by ingroup trust and not by fairness considerations. Implications for research on social value orientations, and intergroup conflict and competition are discussed.