Philip G. Zimbardo is an American psychologist, who has been on the faculty of Stanford University since 1968, where he is now Professor Emeritus. Previously, he taught at Yale University, New York University and Columbia University. He was president of the American Psychological Association in 2002. His doctorate is from. is from Yale (1959) and BA from Brooklyn College (1954). He was elected President of the American Psychological Association (2002).
He is probably best known for the Stanford Prison Experiment and subsequent work on the relationships between prisoners and their captors. In broader work on authority and control, he has done substantial work on cults.
Zimbardo has received awards for making psychology available to the public, as in the 26-week Discovering Psychology series on the Public Broadcasting Service.
Stanford Prison Experiment
Zimbardo began, in 1971, what was to be a short study of the interaction between prisoners and captors, in a simulated prison with the guards and prisoners all being paid volunteers. The intensity of reactions evoked were so intense that the experiment was terminated early for safety reasons, but has given substantial insight for penology.
Evil and Heroism
In a book by the name, described some of the behavior as The Lucifer Effect:  "... [the] most extreme transformation imaginable from God’s favorite Angel into the Devil. My work has focused on lesser transformations of human character not as dramatic as this one, in which ordinary, even good people begin to engage in bad deeds, for a short time or longer, that qualify as 'evil.' "
He and his colleague, Zeno Franco, also explore the heroic side of human behavior.  Drawing a contrast to Hannah Arendt's description of Adolf Eichmann , they idetify two kinds of heroes: "those rare people whose whole lives are centered around sacrifice for the good of society or for the well being of their fellows, chronic heroes, and those ordinary folks who are moved to an heroic deed in a specific situation at a particular time." The latter ae people who say "I did what I had to do" or "it was nothing special", which he trades off against Eichmann by calling it "the banality of heroism."
- Stanford Prison Experiment: A Simulation Study of the Psychology of Imprisonment
- Philip Zimbardo, The Lucifer Effect, The Lucifer Effect: Understanding how good people turn evil
- Zeno Franco and Philip Zimbardo, Celebrating Heroism, The Lucifer Effect: Understanding how good people turn evil
- Hannah Arendt, Eichmann in Jerusalem