When it comes to intergroup relations, we think Cicero had it right. For many years, we have argued that interactions between groups-often negative, but sometimes positive-cannot be understood without investigating the emotions that group members feel toward their own and other groups. We have argued that such emotions come with the psychological territory of group membership itself, and depend in crucial ways on how psychologically deeply or centrally group membership is accepted. Like Cicero, we have argued that it is well worth distinguishing the possible effects of negative emotions such as rage, sorrow, and fear for understanding intergroup relations, and like Cicero, we see the power of positive as well as negative emotions in guiding behavior between groups. In step with his times, Cicero no doubt considered emotion an individual phenomenon, whereas we have argued for the essentially social underpinning of emotion, and thus that emotion is also interpersonal and intergroup in nature. Also in step with his times, Cicero referred to “men” when we hope he meant human beings, but we agree with his use of the plural term-we have argued that emotion is a shared product of group life and that it creates shared tendencies to act in common ways toward collective others.