Cooperation and the In-Group-Out-Group Bias: A Field Test on Israeli Kibbutz Members and City Residents

The in-group-out-group bias is among the most well documented and widely observed phenomenon in the social sciences. Despite its role in hiring decisions and job discrimination, negotiations, and conflict and competition between groups, economists have heretofore ignored the in- group-out-group bias. We question the universality of the bias by designing field experiments to test whether it extends to the cooperative behavior of one of the most successful and best-known modern collective societies, the Israeli kibbutz. The facts that kibbutz members have voluntarily chosen their lifestyle of cooperation and egalitarianism, the ease with which they could join the surrounding capitalist society, their disproportionate involvement in social and national causes and their revealed willingness to sacrifice for the benefit of Israeli society as a whole suggest that if ever there was a society of individuals whose cooperativeness extends equally to members and non-members, the kibbutz is it. Nonetheless, the findings from our field experiments indicate that kibbutz members display higher levels of cooperation when paired with anonymous kibbutz members than when paired with city residents. In fact, when paired with city residents, kibbutz members’ observed levels of cooperation are identical to those displayed by the city residents. Moreover, we present evidence that kibbutz socialization actually damages the willingness of members to cooperate with one another.