In-group bias arises even without conflict, hostility, or self-interest

Evidence

In this situation, there is neither a conflict of interests nor previously existing hostility between the “groups.” No social interaction takes place between the subjects, nor is there any rational link between economic self-interest and the strategy of in-group favoritism. Thus, these groups are purely cognitive and can be referred to as “minimal.” — John T. Jost and Jim Sidanius, Political Psychology, 2705

Categorization

• DEFINE: “Minimal” groups are defined by being purely cognitive with no interaction, conflict, or self-interest.
• DEEPTHINKING: This is the foundational counter-intuitive finding of social identity theory: bare categorization, stripped of all the usual motivating conditions, still produces favoritism.
• XREF: connects to: Group-level threats trigger bias even absent direct threat to the self. — Blake M. Riek, Eric W. Mania, and Samuel L. Gaertner, Intergroup Threat and Outgroup…, 28