In-group favoritism

In-group favoritism, sometimes known as in-group–out-group bias, in-group bias, or intergroup bias, is a pattern of favoring members of one's in-group over out-group members. This can be expressed in evaluation of others, in allocation of resources, and in many other ways.

This interaction has been researched by many psychologists and linked to many theories related to group conflict and prejudice. The phenomenon is primarily viewed from a social psychology standpoint. Two prominent theoretical approaches to the phenomenon of in-group favoritism are realistic conflict theory and social identity theory. Realistic conflict theory proposes that intergroup competition, and sometimes intergroup conflict, arises when two groups have opposing claims to scarce resources. In contrast, social identity theory posits a psychological drive for positively distinct social identities as the general root cause of in-group favoring behavior.

In 1906, the sociologist William Sumner posited that humans are a species that join together in groups by their very nature. However, he also maintained that humans had an innate tendency to favor their own group over others, proclaiming how "each group nourishes its own pride and vanity, boasts itself superior, exists in its own divinities, and looks with contempt on outsiders" (p. 13). This is seen on the group level with ingroup–outgroup bias. When experienced in larger groups such as tribes, ethnic groups, or nations, it is referred to as ethnocentrism.

Realistic conflict theory (or realistic group conflict) posits that competition between groups for resources is the cause of in-group bias and the corresponding negative treatment of members of the out-group. Muzafer Sherif's Robbers Cave Experiment is the most widely known demonstration of realistic conflict theory. In this experiment, 22 eleven-year-old boys with similar backgrounds were studied in a mock summer camp situation. The boys were divided into two equal groups and encouraged to bond, and then the researchers introduced a series of competitive activities in which the groups were pitted against one another. Hostility and out-group negativity ensued. Researchers then attempted to reverse the hostility by engaging the boys in situations of mutual interdependence, an effort which eventually resulted in relative harmony between the two groups. This study demonstrated that, regardless of two groups' similarity, group members will behave viciously toward the out-group when competing for limited resources.

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