out-group

Meaning: An out-group is any group a person does not belong to or identify with. The in-group is the group they do belong to. Social identity theory (Tajfel and Turner) explains the contrast: part of self-esteem comes from group membership, so people tend to raise the status of their own group and lower that of others. This produces in-group bias, stereotyping and prejudice toward the out-group. It also produces the out-group homogeneity effect: "they are all alike," while "we are diverse." Competition between groups for limited resources can intensify hostility (Sherif's Robbers Cave study), and shared goals that need cooperation can reduce it.

On the MCAT: Passages describe an experiment or scenario in which people are sorted into groups, sometimes by trivial or random criteria (the minimal group paradigm), and then favor their own group. Questions ask you to name the phenomenon (in-group bias, out-group homogeneity), predict how attitudes change under competition versus cooperation, or link the idea to prejudice and discrimination.

Common confusion: An out-group is defined relative to the person, not by size or power. The same group is an in-group to its members and an out-group to others. It is also not the same as a reference group, which is a standard of comparison that may or may not include the person.