Philip George Zimbardo (; March 23, 1933 – October 14, 2024) was an American psychologist and a professor at Stanford University. He was an internationally known educator, researcher, author and media personality in psychology who authored more than 500 articles, chapters, textbooks, and trade books covering a wide range of topics, including time perspective, cognitive dissonance, the psychology of evil, persuasion, cults, deindividuation, shyness, and heroism.
Zimbardo garnered great attention for his 1971 Stanford prison experiment, which was later criticized for its use of methods that allowed Zimbardo himself and whatever biases he may have had to influence the results. He authored various widely used, introductory psychology textbooks for college students, and other notable works, including Shyness, The Lucifer Effect, and The Time Paradox.
Zimbardo 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. He pioneered The Stanford Shyness Clinic in the 1970s and offered the earliest comprehensive treatment program for shyness. He was the recipient of numerous honorary degrees and many awards and honors for service, teaching, research, writing, and educational media, including the Carl Sagan Award for Public Understanding of Science for his Discovering Psychology video series. He served as Western Psychological Association president in 1983 and 2001, and American Psychological Association president in 2002.
Zimbardo was born in New York City on March 23, 1933, to a second-generation Sicilian-American immigrant family. Early in life he experienced discrimination and prejudice, growing up poor on welfare in the South Bronx, and being Italian. Zimbardo said these experiences early in life started his curiosity about people's behavior, and later influenced his research in school.He survived an early childhood illness and the experience of a long stay at the Willard Parker Hospital, a hospital for children with contagious diseases, where he learned to read. His formal education began in New York Public School 52 and he graduated from James Monroe High School. He was the first member of his family to pursue a college degree.
In 1954, Zimbardo completed his B.A. with a triple major in psychology, sociology, and anthropology from Brooklyn College, where he graduated summa cum laude. He completed his M.S. (1955) and Ph.D. (1959) in psychology from Yale University, where Neal E. Miller was his advisor. While at Yale, he married fellow graduate student Rose Abdelnour; they had a son in 1962 and divorced in 1971.
He taught at Yale from 1959 to 1960. From 1960 to 1967, he was a professor of psychology at New York University College of Arts & Science. From 1967 to 1968, he taught at Columbia University. He joined the faculty at Stanford University in California in 1968 and taught for 50 years there. Following retirement in 2003, he continued to lecture at Stanford and taught at Palo Alto University (former Pacific Graduate School of Psychology) and the Naval Postgraduate School (NPS) in Monterey.
Zimbardo's activism manifested in different ways, such as organizing academic forums called teach-ins on civil rights and racial justice. He 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 controversial figure.
In 1972, he married Christina Maslach, who received her doctorate in psychology at Stanford University in 1971 and had played a role in concluding the Stanford Prison Experiment.
From his first marriage, he had a son and, from the second, two daughters.
Teaching and educational media
Zimbardo was widely known for popular introductory psychology courses. For decades he authored numerous editions of the introductory psychology textbook Psychology and Life and co-authored Psychology: Core Concepts, which have been foundational for many American undergraduate psychology courses.
Throughout his career, he was committed to "giving psychology away" or making psychology accessible to the public, notably through his PBS television series titled Discovering Psychology, which is used in many college telecourses, and his many bestselling academic and popular publications. Discovering Psychology won an Emmy and awards from the American Psychological Association, the Western Psychological Association, and the Columbus International Film & Video Festival. He sought to bridge the gap between academia and the broader audience by using mass media to communicate his work. 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. These Candid Camera Classics programs were created for psychology classes and released on DVD, for use in both introductory psychology and social psychology courses.
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". Colleague Ewart Thomas, professor emeritus of psychology and former dean of the School of Humanities and Sciences at Stanford, noted that Zimbardo was "famous for inspiring many of his students to pursue research and teaching careers in which they, like their mentor, were recognized for their distinguished teaching".
His teaching career was recognized with numerous awards, including Distinguished Teaching Award, New York University (1965), Distinguished Teaching Award for Outstanding Contributions to Education in Psychology, American Psychological Foundation (1975), Phoenix Award for Outstanding Teaching, Stanford Psychology Department Faculty (1984), California Magazine, Best Psychology Teacher in California (1986), The Walter Gores Distinguished Teaching Award, Stanford University (1990), Bing Fellow Outstanding Senior Faculty Teaching Award, Stanford University (1994–1997), Outstanding Teaching Award, Western Psychological Association (1995), Distinguished Teaching Award, Phi Beta Kappa (1998), Robert S. Daniel Teaching Excellence Award, APA Division 2, Society for the Teaching of Psychology (1999), and Dean's Award for Distinguished Teaching, Stanford University (1999–2000).
Philip Zimbardo was a psychologist known for his research in how individual behavior is shaped by social systems, situations and contexts.
Attitude change and cognitive dissonance
Zimbardo undertook graduate school training in the Yale Attitude Change Program, headed by his mentor, Carl Hovland, an influential psychologist in his own right. This experience inspired a long term interest in the processes of attitude and behavior change produced by persuasion. Zimbardo's work on dissonance began during graduate school and he wrote his dissertation on this topic after being introduced to Leon Festinger's work by his Yale mentors in 1957. He conceptualized dissonance phenomena as the cognitive control of motivation, and demonstrated the power of this approach in a series of experimentally rigorous studies. This dissertation work was published in 1960 in the Journal of abnormal and social psychology. Among other publications on principles of behavior and attitude change, the book he co-authored with Michael Leippe, The Psychology of Attitude Change and Social Influence, part of the McGraw-Hill Series in Social Psychology, covered the relationships existing between social influence, attitude change and human behavior.
Zimbardo's long-term research interests included cultic behavior. He 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. After working personally with several members of Jim Jones's Peoples Temple cult who had escaped the massacre of cult members in the Guyana jungle in 1978, Zimbardo became fascinated with the intense psychological context and forces involved in cult recruitment, identification, and internalization, and how they could be resisted.