The Influence of Philip Zimbardo on Psychology

Philip Zimbardo
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Philip Zimbardo is an influential psychologist best-known for his 1971 Stanford Prison Experiment. Many psychology students may also be familiar with his introductory psychology textbooks and Discovering Psychology video series, which are often used in high school and psychology classrooms. He is also known for his research on shyness. Zimbardo is the author of several notable books including The Lucifer Effect: Understanding How Good People Turn Evil.

Zimbardo has also conducted important research on the psychology of heroism and is the founder of the Heroic Imagination Project, a non-profit organization aimed at understanding and promoting everyday heroism.

His Early Life

Philip Zimbardo was born on March 23, 1933, in New York City. He attended Brooklyn College where he earned a BA in 1954, triple majoring in psychology, sociology, and anthropology. He then went on to earn his MS in 1955 and his PhD in 1959 from Yale University, both in psychology.

He taught briefly at Yale before becoming a psychology professor at New York University, where he taught until 1967. After a year of teaching at Columbia University, he became a faculty member at Stanford University in 1968, where he worked until his retirement in 2003. He delivered his final lecture at Stanford in 2007.

Zimbardo's Career and Research

Zimbardo's career has spanned decades and covered a wide variety of subjects, from social conformity to shyness to military socialization.

Stanford Prison Experiment

Philip Zimbardo is perhaps best known for the Stanford Prison Experiment, conducted in the basement of the Stanford University psychology department in 1971. The participants in the study were 24 male college students who were randomly assigned to act either as "guards" or "prisoners" in the mock prison.

The study was initially slated to last two weeks but had to be terminated after just six days because of the extreme reactions and behaviors of the participants. The guards began displaying cruel and sadistic behavior toward the prisoners, while the prisoners became depressed and hopeless.

While the study is a staple of psychology textbooks and its events portrayed in a feature film, recent findings indicate that the experiment lacked credibility and authenticity. In an exposé titled "The Lifespan of a Lie," journalist Ben Blum reported that the experimenters intentionally influenced the experiment and the results.

Zimbardo Time Perspective Inventory (ZTPI)

Zimbardo also developed an inventory to measure time perspective, which is believed to significantly influence human behavior. It includes people's views of past, current, and future behavior.

Social Intensity Syndrome (SIS)

Zimbardo also developed a social intensity syndrome (SIS) theory to describe how military culture and socialization affect soldiers and military veterans. Research has demonstrated that the construct is an accurate measure of military socialization. Zimbardo and his colleagues suggest that SIS may be an important way to gain better insight into military culture's positive and negative effects.

The Shyness Clinic

Zimbardo has also researched the effects of shyness and how it can be treated in both children and adults. He established The Shyness Clinic, located in Palo Alto, California, to research traits associated with shyness and provide treatment for shy behaviors, primarily through practicing social skills and engaging in social activities.

"Psychology of Evil" TED Talk

In 2008, Zimbardo delivered a TED Talk on the psychology of evil. He summarized research on evil, discussed how these insights explained the atrocities at Abu Ghraib, and how people can practice heroism in their everyday lives.

Heroic Imagination Project

Today, he continues to work as the director of the Heroic Imagination Project. The organization promotes research, education and media initiatives designed to inspire ordinary people to act as heroes and agents of social change.

Notable Publications

Zimbardo has published a number of books, textbooks, and journal articles throughout his career. Some of the most notable include:

The Lucifer Effect

Zimbardo's 2007 book included his account of the events of the 1971 Standford Prison Experiment. The book explored why people sometimes do bad things and how people cross the line from good to evil, often without realizing what they have done.

The Time Paradox

In "The Time Paradox: The New Psychology of Time That Will Change your Life," Zimbardo and his co-author John Boyd explored how people's attitudes toward time shape their behaviors and decisions. It also explored how distorted perceptions of time can contribute to mental health problems.

The Time Cure

In this book, Zimbardo and his co-authors Richard and Rosemary Sword take the concept of time perspective and apply it to the treatment of post-traumatic stress disorder (PTSD). By shifting how people think about time, Zimbardo and his colleagues suggested, people can better move past the trauma they have experienced.

Zimbardo's most recent publication is the 2015 book "Man (Dis)connected: How Technology Has Sabotaged What It Means To Be Male."

His Contributions to Psychology

Philip Zimbardo’s Stanford Prison Experiment has long served as an example of how situational forces influence human behavior. The study became a topic of interest after the reports of the Abu Ghraib prisoner abuses in Iraq became public knowledge. Many people, Zimbardo included, suggested that the abuses at Abu Ghraib might be real-world examples of the same results observed in Zimbardo's experiment.

Since the famous prison experiment, Zimbardo has researched various topics, including shyness, cult behavior, and heroism. He has authored and co-authored numerous books some people may recognize him as the host of the Discovering Psychology video series, which has aired on PBS and is often used in high school and college psychology classes.

In 2002, Zimbardo was elected president of the American Psychological Association. After more than 50 years of teaching, Zimbardo retired from Stanford in 2003 but gave his last "Exploring Human Nature" lecture on March 7, 2007.

Zimbardo has also served as an influential figure in psychology through his writings as well as his long teaching career.

A Word From Verywell

While Zimbardo's best-known experiment took place decades ago, its impact is still felt on psychology today. The images of torture and prisoner abuse that emerged from the Iraq prison known as Abu Ghraib echoed the notorious events in Zimbardo's infamous experiment.

The Stanford Prison Experiment has long been one of the most famous experiments in psychology. However, it has long been criticized for its ethical problems and, more recently, its scientific credibility has been called into question.

Frequently Asked Questions

  • Is Philip Zimbardo still alive?

    Zimbardo is now 89 years old. He retired from teaching at Stanford after a 50-year career but continues to work as the director of the Heroic Imagination Project, the organization he founded to explore the psychology of everyday heroism.

  • Why did the Stanford Prison Experiment lose credibility?

    Recent critiques have called the Stanford Prison Experiment's scientific credibility into question. In addition to the problematic ethical concerns with the research, new examinations suggest the experimenters intentionally encouraged the abusive behavior of the prison guards. A 2019 article published in American Psychologist debunked the famous experiment, declaring the study both deeply flawed and unworthy of the attention it has commanded for decades. 

  • What are Philip Zimbardo’s theories about time?

    Zimbardo suggested that there are five different time perspectives: 

    • Past-positive perspective involves positive evaluations of the past. 
    • Past-negative perspective involves negatively evaluating the past. 
    • Future-perspective involves goal-based thinking about the future.
    • Present-hedonistic perspective involves focusing on finding pleasure in the present moment.
    • Present-fatalistic perspective involves existing passively in the present and believing that events are fated or pre-destined.
11 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Zimbardo P, Haney C, Banks WC, Jaffe D. The Stanford Prison Experiment: A simulation study of the psychology of imprisonment. Stanford University, Stanford Digital Repository, Stanford.

  2. American Psychological Association. Philip G. Zimbardo: 2002 APA President.

  3. American Psychological Association. Demonstrating the power of social situations via a simulated prison experiment.

  4. Blum B. The lifespan of a lie.

  5. Peng C, Yue C, Avitt A, Chen Y. A systematic review approach to find robust items of the Zimbardo time perspective inventory. Front Psychol. 2021;12:627578. doi:10.3389/fpsyg.2021.627578

  6. Zimbardo PG, Ferreras AC, Brunskill SR. Social intensity syndrome: The development and validation of the social intensity syndrome scale. Personality and Individual Differences. 2015;73:17-23. doi:10.1016/j.paid.2014.09.014

  7. TED. The psychology of evil.

  8. American Psychological Association. Psychological science offers clues to Iraqi prisoner abuse.

  9. Stanford University. About Philip G. Zimbardo.

  10. Le Texier T. Debunking the Stanford Prison ExperimentAmerican Psychologist. 2019;74(7):823-839. doi:10.1037/amp0000401

  11. Sobol-Kwapińska M, Jankowski T, Przepiorka A, Oinyshi I, Sorokowski P, Zimbardo P. What is the structure of time? A study on time perspective in the United States, Poland, and Nigeria. Front Psychol. 2018;9:2078. doi:10.3389/fpsyg.2018.02078

By Kendra Cherry
Kendra Cherry, MS, is an author and educational consultant focused on helping students learn about psychology.