[Ongoing group interaction, ingroup favoritism, and reward allocation].

Two alternative explanations for ingroup favoritism in the minimal group situation have been proposed: social identity and expectations of bounded generalized reciprocity. In this study, predictions derived from the two were examined for ingroup favoritism in a realistic group salutation with ongoing interactions. Results of the experiment, a replication of Karp, Jin, Yamagishi, and Shinotsuka (1993) which used groups with ongoing interactions rather than minimal groups, were inconsistent with either of the two explanations. (1) Ingroup favoritism emerged even in the condition under which the nature of fate control was unilateral. The finding was in sharp contrast to results of previous minimal groups experiments; the studies found ingroup favoritism only when fate control was mutual. (2) Analysis of post-experimental questionnaire responses indicated that participants engaged in ingroup favoritism, not to maximize differences between ingroup and outgroup but to improve ingroup members' gain. (3) Analysis of participants' open-ended self-reports revealed that they engaged in ingroup favoring reward allocation because of their personal bonds and likings for ingroup members as individuals rather than of their identification with the group per se.