Trait Negative Reputational Concerns Among In-group Members and In-group Favoritism in Minimal Groups

People tend to behave more cooperatively with in-group members than out-group members, even in minimal group situations. This study investigated the relationship between trait reputational concern (fear of negative evaluation) from in-group members and in-group favoritism in minimal group contexts. A total of 176 participants completed hypothetical prisoner’s dilemma games; when reputation was at stake, in-group favoritism was significantly associated with trait negative reputational concern. In this context, greater concerns about reputation from in-group members resulted in stronger in-group favoritism. By contrast, in-group favoritism under anonymity was not related to trait reputational concern. We also measured fear of negative reputation from others, finding that in-group favoritism was correlated with both trait reputational concern from in-group members and others in general as long as reputation was at stake.