Out-group favouritism

In-group favouritism, the practice of treating fellow members of a group better than outsiders is commonplace in social life. It has been observed in the field and the laboratory. Treating people differently in this way is not only a source of tension between groups, when conflict occurs between groups, it may also be linked to the evolutionary development of altruistic or cooperative behaviour within the group. We report here on what may seem, in this context, a surprising experimental result: a form of out-group favouritism in a trust game that is played among the Gisu in Uganda. There is, however, some evidence in the experiment that the absence of in-group favouritism is accompanied by a negligible influence of group membership on trust between fellow group members. This is consistent with those evolutionary arguments which link parochialism (i.e. hostility to outsiders) to altruism (within the group) in the sense that the absence of one is also associated with the absence of the other. Both results reinforce the thought that evolutionary accounts of behaviour should not always assume inter-group hostility and more attention needs to be given to the circumstances under which the character of inter-group relations varies.