This chapter explores the psychology of large-scale political conflict, violence, and political transformation within and among nation-states. Political psychology explores the border that runs between the intellectual nations of political science and psychology. Political psychologists belong to a relatively young interdisciplinary community that not only draws on theories and methods from psychology and political science, but is also happy to borrow from neighboring fields such as international relations, anthropology, sociology, oganizational behavior, economics, history, and philosophy. The International Society of Political Psychology was founded in 1977; its first annual convention was held in 1978; and its flagship journal, Political Psychology, was launched in 1979. The study of personality and politics is one of the oldest and most central topics in political psychology. In contrast to most theories in political psychology, the social dominance perspective is also situated squarely within the emerging framework of evolutionary psychology.