Psychologist, Professor at the Pacific Graduate School of Psychology, (since 2006). Mr. Zimbardo is also Distinguished Senior Fellow at the Center for Homeland Defense and Security at the Naval Postgraduate School in Monterey and Executive Director of the Center for Interdisciplinary Policy, Education, and Research on Terrorism, Stanford Medical School. He served as President of the American Psychological Association. He has been a Stanford University professor since 1968, having taught previously at Yale, NYU and Columbia. He is known for his Stanford prison study.