Ingroup preference psychologically precedes outgroup hostility, which stems from other sources.

Evidence

Allport suggested that, while the presence of another group, especially in conflictual situations, can increase ingroup cohesion, such cohesion need not lead to prejudice and outgroup hostilities (p. 42). In fact, he proposed that ingroup attachment and preference are psychologically more primary motives and that outgroup hostility usually stems from other sources, an argument that has been resurrected in recent years (Brewer, 1999). 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. — , Rudman, Laurie A - On the Nature of…, 427

Categorization

• XREF: Inverts Sumner’s earlier ethnocentrism claim that ingroup loyalty implies outgroup hostility — connects to minimal group paradigm work.