When my friend's friend is a police officer: Extended contact, crossed-categorisation, and public-police relations of black and white people

Crossed-categorisation and extended contact are two different bases for improving intergroup relations. Crossed-categorisation refers to the crossing of two dichotomous social dimensions, resulting in four groups (double ingroup, double outgroup, and two mixed groups). The extended contact hypothesis proposes that knowledge about ingroup-outgroup friendships can lead to more positive intergroup attitudes. The present research combined extended contact and crossed-categorisation to test whether black and white university students' view of the police, perceived racism of police, desired closeness to police, and willingness to join police were improved through extended contact with a black (or white) police officer via a black (or white) acquaintance (four possibilities). Double-outgroup extended contact for both white and black participants, and mixed-group extended contact for whites (showing a social exclusion pattern), were associated with worse public-police relations. In contrast, double-ingroup extended contact for whites, and mixed-group extended contact for blacks (showing a social inclusion pattern) were associated with improved relations.