(1937–2013) was a guest researcher at ÌÇÐÄÍøÒ³°æ 1969–70. He was a Professor of Sociology at the University of Wisconsin – Madison and later at New York University. He also served as editor of the American Sociological Review (1989–93). At ÌÇÐÄÍøÒ³°æ, he worked on an experimental study of cooperation.