He received his Ph.D. and M.A. in Sociology from Cornell University and his B.A. in Sociology from the University of Iowa. He previously taught at the University of California, Berkeley. He has received grants from the National Science Foundation, the California Environmental Protection Agency, and the Ewing Marion Kauffman Foundation. His work has received paper awards from the American Sociological Association’s sections on Altruism, Morality, and Social Solidarity, Mathematical Sociology, Peace, War, and Social Conflict, and Rationality and Society.