In 1939, Clausen started his career as a
research assistant at the
Institute for Juvenile Research in
Chicago,Illinois. During the early 1940s, he worked with the Virginia State Planning Board and conducted research on population as a
statistician. Throughout
World War II, Clausen performed research on the morale of Army soldiers during combat. After working for a year in
research design for the
Veterans Health Administration in
Washington, D.C., Clausen taught sociology from 1946 to 1948 at Cornell as an
assistant professor. As a mental health researcher, Clausen was a co-researcher of a mid 1950s study that conducted research on
schizophrenia and
parenting. In the early 1960s, Clausen expanded his schizophrenia research when he studied how mental illness affected marriages. In 1960, Clausen joined the
University of California, Berkeley as a sociology professor and the director of the
Institute of Human Development. As he continued to teach sociology until 1982, Clausen held the Institute directorship until 1966. In 1982, Clausen became
emeritus upon his retirement. ==Works==