Leary, Timothy (1920–1996)

US writer and psychologist. Leary was one of the more controversial and influential psychologists of the last 41 years and a guiding iconic figure of the counter-culture of the 1960s and 1970s. Leary helped develop the theory of transactional analysis and conducted a series of psychedelic experiments at Harvard University that helped pave the way for an era of cultural and psycho-social upheaval. His book The Interpersonal Diagnosis of Personality enjoys wide-ranging praise and influence.

Born in Springfield, Massachusetts, he studied at Holy Cross College, West Point, and the University of Alabama. He earned a doctorate in psychology from the University of California at Berkeley in 1950. By the mid-1950s, Leary was teaching at Berkeley and had been appointed director of psychological research at the Kaiser Foundation, in Oakland, California.