Robin Murphy Williams Jr., the Henry Scarborough Professor Emeritus of Social Science at Cornell University and a highly respected sociologist known for his love of teaching, wit and humor, died June 3 in Irvine, Calif. He was 91.

A member of Cornell's Department of Sociology from 1946 to 2003 and chair of the department from 1956 to 1961, Williams was appointed to the Scarborough professorship in 1967. After becoming professor emeritus in 1985, he continued to teach at Cornell and at the University of California-Irvine, where he was a distinguished visiting professor.

Williams' scholarship concentrated on race relations, war and peace, ethnic conflict, and altruism and cooperation in works including "Schools in Transition," "Strangers Next Door, American Society: A Sociological Interpretation" and "The Wars Within: Peoples and States in Conflict."

The author of more than 150 articles, monographs and chapters in edited volumes, he was a member of the American Philosophical Society, the American Academy of Arts and Sciences, the National Academy of Sciences, the National Research Council and the Pacific Sociological Association. Among other honors, Williams received the Commonwealth Award for Distinguished Service and the American Sociological Association's Career of Distinguished Scholarship Award. The Robin M. Williams Jr. Distinguished Lectureship Award was established by the Eastern Sociological Association in 1992 to honor Williams' many contributions to sociology and the society, particularly as founding editor of its journal, Sociological Forum, now in its 20th year.

In 1996 Cornell honored Williams by holding a two-day symposium, "American Society: Diversity and Consensus," which acknowledged and built on Williams' work on diversity and consensus in values, beliefs and the broader social fabric.

Williams was born Oct. 11, 1914, in Hillsborough, N.C. He received his B.S. (1933) from North Carolina State College, his M.S. (1935) from North Carolina State University and the University of North Carolina, and M.A. (1939) and Ph.D. (1943) degrees from Harvard University. During World War II he served in the Special Services Division of the U.S. War Department in Washington, D.C., and the European Theater of Operations from 1942 to 1946. As an Army researcher on the front lines, he contributed to the classic work "The American Soldier."

He is survived by his wife, Marguerite, two daughters and four grandchildren. Contributions can be made to Amnesty International or Doctors Without Borders.