The mission of Pi Gamma Mu is to encourage and promote excellence in the Social Sciences and to uphold and nurture scholarship, leadership, and service. Pi Gamma Mu serves the various social science disciplines which seek to understand and explain human behavior and social relationships as well as their related problems and issues. Currently, there are around 150 active chapters in the United States and overseas. Pi Gamma Mu's constitution defines the social sciences to include the disciplines of history, political science, sociology, anthropology, economics, psychology, international relations, criminal justice, social work, social philosophy, history of education, and cultural/human geography.