Seymour “Sy” Feshbach, professor emeritus of psychology and a pioneering researcher on behavioral theories of aggression, died in November in Los Angeles. He was 95.

Feshbach came to UCLA’s psychology department in 1964, where he was instrumental in starting a nationally recognized personality program. He was chair of the department for five years as well as chair of UCLA’s Academic Senate. He also served as president of the International Society for Research on Aggression and as president of the Society for the Psychological Study of Social Issues.

Feshbach’s research has been at the center of academic discourse on aggression since his doctoral dissertation at Yale in 1951, in which he tested and found evidence for Freud’s catharsis hypothesis — the idea that sexual and aggressive goal attainment through fantasies reduces those urges. He became an international leader in the study of aggression, and he was a key voice in discussions regarding the effects of observing violence in media. He received the Karpf Peace Prize from UCLA for his contributions toward understanding aggression and promoting peace.

Feshbach’s friends, family and colleagues remember him not only as a revolutionary researcher, but also as a kind and good-natured man. Even after his retirement in 1995, he remained engaged with the psychology department, continuing to contribute gifts to the annual Christmas party.

Feshbach was born on June 21, 1925, in New York City. In 1943, he enlisted in the U.S. Army and served in World War II. Shortly after the war ended, he attended the City College of New York for his bachelor’s degree. He then received a doctorate in psychology from Yale University. Not long after taking his first faculty position at the University of Pennsylvania, he returned to active military service during the Korean War, applying his studies in psychology to classified work at the Pentagon.

He is survived by his wife, Norma, who is an accomplished UCLA professor emeritus of education, and their two children (a third child did not survive him), six granddaughters and three great-grandchildren.