This article uses political psychology to understand emotions such as anger, hate, and passion in the Brexit debate in order to demonstrate the wider value of the political psychology of European integration. It uses five strands of political psychology to understand European integration, drawing on evidence from the Brexit debate. These strands are individual cognitive psychology, social psychology, social construction, psychoanalysis, and critical political psychology. The article argues that the political psychology of European integration demands an understanding of the interwoven nature of feelings and illusions, the bidirectional interaction of political and psychological processes, and the multiplicity of strands of political psychology in the mutual accommodation and inclusion by European states and peoples. Only in this way is it possible to even begin to comprehend the many ways in which identity and difference are (re)produced by all partners in the Brexit debate and what these processes mean for the wider study of the political psychology of European integration.