The couple divorced in 1978. A previous marriage also ended in divorce. Along with her daughter, Dr. Caplan is survived by her son, Jeremy; her brother, Bruce; and five grandchildren.

After moving to Canada, Dr. Caplan was a psychologist for the Toronto Family Court for three years. Among her first efforts was a study of assertiveness among girls and boys, following on the work of the prominent German American psychologist Erik Erikson, in which he had concluded that boys were innately more assertive than girls.

Dr. Caplan showed otherwise. Focusing on very young children and diminishing the presence of adults in the room during the study, she demonstrated that it was gendered socialization, not biology, that made girls act less assertively than boys.

Dr. Caplan was a professor at the University of Toronto from 1979 to 1995 and head of its Center for Women’s Studies in Education from 1985 to 1987. She later taught at American University, the University of Rhode Island, Brown University and, most recently, Harvard, where she ran the Voices of Diversity Project at the Hutchins Center for African & African American Research.

Dr. Caplan’s work extended beyond academic psychology. An actor since high school, she had small parts in TV shows and commercials, only some of which had anything to do with her intellectual pursuits.

She wrote plays and directed documentary films, including “Isaac Pope: The Spirit of an American Century” (2019), about a Black man who had served in the Army under her father in the Battle of the Bulge during World War II.

The film was of a piece with her latest interest, veterans and specifically those deemed to be suffering from post-traumatic stress disorder, a diagnosis she largely rejected. There was nothing pathological about having a strong, even debilitating reaction to the horrors of war, she said, and our desire to medicalize those reactions made it possible for nonveterans to ignore just how terrible war could be.

“Leaving this work to psychotherapists alone may be not only harmful to the soldiers but also dangerous for us as a nation,” she wrote in The Washington Post in 2004. “It helps hide the consequences of combat, making it easier for us to go to war again the next time.”