Philip G. Zimbardo (born March 23, 1933) is an American psychologist best-known for the Stanford prison experiment, in which 24 college students were randomly assigned to be prisoners or guards in a mock prison located in the basement of the psychology building at Stanford University. The resulting sadism exhibited by some "guards", and corresponding depression and passivity of "prisoners", led to theories about the importance of social position in individual psychology that are still controversial today.
Zimbardo is also well-known for his textbooks, which are used in many American undergraduate psychology courses. He also hosted a PBS TV series titled "Discovering Psychology." He was also president of the American Psychological Association in 2002. His main role now is as founder and mentor of The Shyness Clinic in Menlo Park, California, which treats shy benavior in adults and children.
Zimbardo grew up in New York City, in the South Bronx, and went to Monroe High School with Stanley Milgram. He earned his Bachelor's degree from Brooklyn College, and his Master's degree and Ph.D. from Yale University.
Beginning in 1968, Zimbardo was a professor of psychology at Stanford University. He retired in November 2003 but he still returns each winter to teach "Exploring Human Nature", a "greatest hits" course of his favorite topics.
In 2002, he appeared in the reality television show The Human Zoo. Participants were observed inside a controlled setting while Zimbardo gave psychological commentary on their behavior.
In 2004 he testified in the case of "Chip" Frederick, a guard at Abu Ghraib and argued that Chip's sentence should be lessened since Zimbardo's prison experiment had shown that few can resist the powerful situational inducements. The judge apparently disagreed and gave Chip the maximum sentence.
His wife, Christina Maslach, is a psychology professor at UC Berkeley.