Peter Bearman is Director of the Institute for Social and Economic Research and Policy and the Paul F. Lazarsfeld Center for the Social Sciences at Columbia University. His research cuts across a number of sub-disciplines within sociology, from historical sociology, collective action, social networks, and social theory to problems in population. With J. Richard Udry, he designed and directed the National Longitudinal Study of Adolescent Health (Add Health). His current research arising from Add Health focuses on how the structure of romantic and sexual networks shapes STD risks for adolescents, the long-term consequences of adolescent virginity pledges, peer influence, and genetic influence on social behavior. His current research in historical sociology focuses on developing models to case historical event sequences; temporality in historical accounts; recruitment to elite positions, and the structure of global trade networks, 1600-1831. In the area of social networks, his current work focuses on the structure of Italian politics (1986-2002).