Ingroups need not be defined in opposition to outgroups

Evidence

Although Allport acknowledged that, in strict logic, an ingroup always requires the existence of some outgroup, he argued that this does not mean that the ingroup necessarily needs to be defined in relation or opposition to this outgroup. — John F. Dovidio, Peter Glick, Laurie A. Rudman, On the Nature of Prejudice, 427

Categorization

• XREF: Connects to minimal group paradigm findings and to Brewer’s optimal distinctiveness theory, both of which follow the same premise that ingroup preference can exist without outgroup derogation. — connects to: The emergency itself, not an outgroup, can define group boundaries — John Drury, The role of social identity processes…, 49; Tribes can exclude members on gendered marriage lines; Constituting the people politically need not preclude pluralism within that association — Chantal Mouffe, The Democratic Paradox, 242