他者の報酬分配への期待と内集団びいきについて

抄録

The purpose of this study was to investigate people's expectation of others' ingroup favoritism, and the effect of expecting others to take part in reward allocation decision on ingroup favoritism in reward allocation. Subjects were randomly assigned to two groups, and were asked to rate attractiveness of ingroup members, and to allocate reward to ingroup and outgroup under two conditions. In the unilateral condition, the subject alone was to make the decision, and in the multilateral condition, every subject was to. The results indicated that equally in all conditions, subjects rated ingroup members more attractive, and expected others to allocate more reward to own groups. Reward allocation that favored ingroup occurred only under the multilateral condition, where everyone participated in reward allocation, regardless of whether the subject's own reward was dependent on others' decisions or was a fixed amount. The findings suggest that ingroup favoritism was not a result of quasi-strategy of self-interest in an attempt to maximize own gains, but of psychological group formation.