He authored various widely-used, introductory psychology textbooks for college students, and other notable works, including Shyness,[3] The Lucifer Effect,[4] and The Time Paradox.

[5] He was the founder and president of the Heroic Imagination Project, a non-profit organization dedicated to promoting heroism in everyday life by training people how to resist bullying, bystanding, and negative conformity.

Dr. Zimbardo organized a walk-out at an NYU graduation ceremony to protest the decision to award an honorary degree to Robert McNamara, the U.S. Secretary of Defense at the time, whose involvement in escalating the Vietnam War made him a highly controversial figure.

He collaborated with Allen Funt, the creator and host of the American hidden-camera show Candid Camera, to produce narrated educational videos that use classic episodes to illustrate key principles of psychology.

[24] Zimbardo, who retired officially in 2003, gave his final lecture, "Exploring Human Nature", on March 7, 2007, on the Stanford campus, celebrating his 50th year of teaching psychology.

David Spiegel, professor of psychiatry at the Stanford University School of Medicine, termed Zimbardo "a legendary teacher", saying that "he has changed the way we think about social influences".

[28] Zimbardo conceived of mind control as a phenomenon encompassing all the ways in which personal, social and institutional forces are exerted to induce compliance, conformity, belief, attitude, and value change in others.

[30] The Lucifer Effect was written in response to the Abu Ghraib torture and prisoner abuse military scandal, which occurred during the United States' invasion of Iraq.

[31] With regards to the events that occurred at the Abu Ghraib Detention Center, the defense team—including Gary Myers—argued that it was not the prison guards and interrogators that were at fault for the physical and mental abuse of detainees but the George W. Bush administration policies themselves.

In The Journal of the American Medical Association,[33] there are seven social processes that grease "the slippery slope of evil":[34] Philip Zimbardo's research on the psychology of evil explores how situational and systemic factors can lead ordinary people to commit harmful or immoral acts, as demonstrated in studies on the dynamics of power, authority, conformity, dehumanization, and moral disengagement.

With a government grant from the U.S. Office of Naval Research, he performed the Stanford prison experiment in which 24 male college students were selected (from an applicant pool of 75).

"I had been conducting research for some years on deindividuation, vandalism and dehumanization that illustrated the ease with which ordinary people could be led to engage in anti-social acts by putting them in situations where they felt anonymous, or they could perceive of others in ways that made them less than human, as enemies or objects," Zimbardo told the Toronto symposium in the summer of 1996.

He instructed guards to find ways to dominate the prisoners, not with physical violence, but with other tactics, such as sleep deprivation and punishment with solitary confinement.

Prisoners and guards had adapted rapidly to their roles, doing more[clarification needed] than had been predicted and resulting in dangerous and potentially psychologically damaging situations.

He did not accept the claim of Chairman of the Joint Chiefs of Staff General Myers that the events were due to a few rogue soldiers and that it did not represent the military.

He argued that Frederick's sentence should be lessened due to mitigating circumstances, explaining that few individuals can resist the powerful situational pressures of a prison, particularly without proper training and supervision.

Zimbardo drew on the knowledge he gained from his participation in the Frederick case to write the book entitled The Lucifer Effect: Understanding How Good People Turn Evil, about the connections between Abu Ghraib and the prison experiments.

[51] After the prison study, Zimbardo decided to search for ways he could use psychology to help people; this resulted in the founding of The Shyness Clinic[6] in Menlo Park, California, to treat shy behavior in adults and children.

[65] Zimbardo was the founder and director of the Heroic Imagination Project (HIP), a non-profit organization dedicated to promoting heroism in everyday life.

[66][2] Since 2010, HIP has been focused on educational programs across the United States and globally in Hungary, Poland, Indonesia, Portugal and Italy, to teach people how to resist behaviors such as bullying, bystander effect, and negative conformity and to encourage positive social action.

[68] The Heroesʼ Square Initiative, Hösök Tere, founded in 2013 by Györgyi Orosz, Péter Halácsy and Philip Zimbardo, was designed to identify and provide tools to overcome the beliefs that prevent people from standing up for others – or even ourselves.

The Heroic Imagination Project has been in collaboration and mentorship with Giocherenda, an organization created by young migrants from Guinea, Gambia, Mali, Burkina Faso, and Morocco.

Giocherenda, which sounds like the Italian word giocare (to play), comes from Pulaar (a West African language) and it means “solidarity, awareness of interdependence, strength through sharing, the joy of doing things together”.

In Portugal the Heroic Imagination Project is being implemented by the Look Around Association, with the impact evaluation being led by the Center for Research on Human Development of the Catholic University of Porto.

), and actively contribute to solving them.In 2008, Zimbardo began working with Sarah Brunskill and Anthony Ferreras on a new theory termed Social Intensity Syndrome (SIS).

[73] In 2003, Zimbardo and University of Rome La Sapienza scholars Gian Vittorio Caprara and Claudio Barbaranelli were awarded the sarcastic Ig Nobel Prize for Psychology[74] for their report Politicians' Uniquely Simple Personalities.

[77] The Lucifer Effect,[33] Zimbardo's firsthand account of the 1971 Stanford prison experiment (SPE), was the William James Book Award winner[78] in psychology in 2008, and was on The New York Times Non-Fiction Best Seller list.

[24] He contributed to educational media projects, most notably as the narrator, writer, and scientific advisor for Discovering Psychology, a 26-program series produced by PBS-TV and the Annenberg Corporation, which has been translated and distributed worldwide (1989, updated 2001).

Zimbardo made appearances on American television, such as The Daily Show with Jon Stewart on March 29, 2007,[83] The Colbert Report on February 11, 2008,[84] and Dr. Phil on October 25, 2010.

From 2003 on, Zimbardo was active in charitable and economic work in rural Sicily through the Zimbardo-Luczo Fund with Steve Luczo and the local director Pasquale Marino [it], which provides scholarships for academically gifted students from Corleone and Cammarata.