The psychology of intergroup relations was grounded in intragroup processes.

Abstract

Although Glowacki proposed that peace developed from the relatively recent advent of intergroup norms and tolerance for out-group members, we submit that (a) positive intergroup relations developed from a psychology grounded in the regulation of intragroup relations, (b) the "default" intergroup orientation is uncertainty, and (c) positive intergroup relations likely existed early in our evolutionary history.