In her 2002 essay “Worrying About Emotions in History,” Barbara Rosenwein problematizes the conventional grand narrative of the history of the emotions, in which the growth of civilization accompanied and encouraged increased emotional restraint. Instead, she argues, we need a more complex narrative to explain the changing role of emotions in history—a narrative that recognizes various “emotional communities” at every period and considers the ways they have changed over time. How, in Rosenwein's words, have different cultures, at different times, “provide[d] for the expression and representation of feeling”? This panel brings together five historians to contribute to Rosenwein's project of a new history of the emotions. In the period after the Second World War, we contend, emotion and its biological substrate, instinct, became newly constituted as legitimate objects of scientific discourse. As mother love and empathy, aggression and violence, came under the increasing scrutiny of scientists in laboratory, clinic, and field, the new sciences of emotion brought new emotional communities into being: they made possible new ways to feel. Biologists, psychologists, and psychiatrists in this period began to represent human beings as containing a biological core that linked them to their animal ancestry and their pre-civilized past, an emotional core driving behavior and needing accommodation though social and political structures. Each of the papers in this panel asks in what ways the conception of humans as emotional/instinctive creatures was connected to social and political history. Marga Vicedo argues that the discovery in the 1950s of mother love by psychoanalysts, ethologists, and psychologists crystallized postwar anxieties about the formation of an emotionally stable self amid the disintegrative forces of the modern world. Susan Lanzoni examines the psychologist Kenneth Clark's use of empathy as an emotional tool for understanding others from different cultures and ethnicities, particularly as a means for creating greater understanding and harmony between whites and blacks. Nadine Weidman discusses a group of popular writers who located an instinct for aggression in human beings, but who believed that aggression was a constructive force and who used their discovery to call for direct political intervention and reform. Erika Milam analyzes a 1960s debate over the moral message contained in an elementary school course of study that, through its representation of a “primitive” people, suggested that human beings were innately violent. Michael Pettit, our commentator, specializes in the cultural history of the human sciences. In our work, the postwar period provides no simple, unified picture of growing emotional restraint; rather, the recognition that humans were emotional creatures created diverse emotional communities, affecting the organization of family life, reconfiguring racial and gender relations, reordering social and political structures, and being accommodated in educational regimes. Nor did the scientists speak with a unified voice: which science was the proper source of authority on human emotion was highly contested. Clearly one cannot understand the history of the emotions in the postwar period without understanding how the human sciences constructed, classified, constrained, and normalized the ways to feel.