Allport doubted contact would reduce prejudice except under specified positive conditions.

Evidence

Allport emphasized proximal, immediate causes and generally disregarded distal, societal causes. So he looked to features of the immediate situation as determinants of intergroup contact’s effects on prejudice. Additionally, both he and Williams (1947) before him doubted whether contact would generally reduce prejudice. Thus, they sought to specify the positive conditions that were necessary for intergroup contact to diminish prejudice. — , Rudman, Laurie A - On the Nature of…, 1705