Arousal of ingroup-outgroup bias by a chance win or loss

Investigated the minimal conditions that produce a more favorable evaluation of the ingroup than the outgroup with 112 Dutch teenagers formed into pairs of groups. Ss, all of whom were strangers, rated 1st impressions of each other and of the 2 groups under 1 of a graded series of experimental treatments. Classifying Ss into 2 groups yielded no difference between the evaluations of in- and outgroups. However, flipping a coin to decide which of the 2 groups would receive a gift produced a significant bias in favor of the ingroup. Results suggested that the chance win-loss created intergroup bias by leading Ss to anticipate better outcomes from interpersonal encounters with ingroup than outgroup members.