Ingroup love is more fundamental to human life than outgroup hate.

Evidence

Allport (1954/1979) also pin-pointed the function of ingroup and outgroup categorization, observing that “the category enables us quickly to identify a related object” (p. 21). With respect to the importance of ingroup identification and how it may be more fundamental to intergroup bias than even outgroup antipathy, Allport remarked that “there is good reason to believe that this love-prejudice is far more basic to human life than is … hate-prejudice. When a person is defending a categorical value of his own, he may do so at the expense of other people’s interests or safety. Hate prejudice springs from a reciprocal love prejudice underneath” (pp. 25–6). — , Rudman, Laurie A - On the Nature of…, 536

Categorization

• XREF: Connects to Brewer’s ‘psychology of optimal distinctiveness’ and the minimal group paradigm literature, where ingroup favoritism precedes outgroup derogation.
• SEED: Angle for an essay: common strategies to reduce prejudice target hate of outgroups, but Allport suggests the roots are in ingroup love — a different intervention target.