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. He became known for his 1971 Stanford prison experiment, which was later criticized. 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.

Early life and education

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. They had two children and were married for 52 years until his death.

Death

Zimbardo died at home in San Francisco on October 14, 2024, at the age of 91. His wife, Christina Maslach, and their children were by his side when he died.

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).

Research

Philip Zimbardo was a trailblazing psychologist known for his research in how individual behavior is shaped by social systems, situations and contexts. “Phil Zimbardo is one of the most prolific and influential psychologists of his generation – a true pioneer of the field of social psychology,” said Claude Steele, the Lucie Stern Professor in the Social Sciences and professor emeritus of psychology at Stanford, “Virtually all of Phil’s research shows how important phenomena of real-life human behavior can be studied scientifically. For a young science like social psychology, this has been an especially important contribution.” Zimbardo's research spanned across multiple topics:

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.

Mind control

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.

Psychology of evil

The Lucifer Effect

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. With renewed global interest in how the lessons of the Stanford Prison Study illuminate parallel dynamics, Zimbardo posited that, in contrast to the U.S. military's explanation of individual dispositional "bad apples", this was a situational "bad barrel" that shaped soldiers' behavior. 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 who were at fault for the physical and mental abuse of detainees but the George W. Bush administration policies themselves. However, this does not deny nor excuse individual accountability. In the book, Zimbardo says that humans cannot be defined as good or evil because they may act as either depending on the situation. He believed that personality characteristics could play a role in how violent or submissive actions are manifested. According to Zimbardo, "Good people can be induced, seduced, and initiated into behaving in evil ways. They can also be led to act in irrational, stupid, self-destructive, antisocial, and mindless ways when they are immersed in 'total situations' that impact human nature in ways that challenge our sense of the stability and consistency of individual personality, of character, and of morality." In The Journal of the American Medical Association, there are seven social processes that grease "the slippery slope of evil":

• Mindlessly taking the first small step
• Dehumanization of others
• De-individuation of self (anonymity)
• Diffusion of personal responsibility
• Blind obedience to authority
• Uncritical conformity to group norms
• Passive tolerance of evil through inaction or indifference

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.

Stanford prison study - Stanford prison experiment

Background

In 1971, Zimbardo accepted a tenured position as professor of psychology at Stanford University. 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). After a mental health screening, the remaining men were assigned randomly to be "prisoners" or "guards" in a mock prison located in the basement of the psychology building at Stanford. Prisoners were confined to a 6 by 9 feet (1.8 m × 2.7 m) cell with black steel-barred doors. The only furniture in each cell was a cot. Solitary confinement was a small unlit closet. Zimbardo's goal for the Stanford Prison study was to assess the psychological effect on a (randomly assigned) student of becoming a prisoner or prison guard. A 1997 article from the Stanford News Service described the experiment's goals in more detail:

Zimbardo's primary reason for conducting the experiment was to focus on the power of roles, rules, symbols, group identity and situational validation of behavior that generally would repulse ordinary individuals. "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.

Experiment

Zimbardo himself participated with the study, playing the role of "prison superintendent" who could mediate disputes between guards and prisoners. 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. Later in the experiment, as some guards became more aggressive, taking away prisoners' cots (so that they had to sleep on the floor), and forcing them to use buckets kept in their cells as toilets, and then refusing permission to empty the buckets, neither the other guards nor Zimbardo himself intervened. Knowing that their actions were observed but not rebuked, guards considered that they had implicit approval for such actions.

In later interviews, several guards told interviewers that they knew what Zimbardo wanted to have happen, and they did their best to make that happen. Less than two full days into the study, one inmate pretended to suffer from depression, uncontrolled rage and other mental dysfunctions. The prisoner was eventually released after screaming and acting in an unstable manner in front of the other inmates. He revealed later that he faked this "breakdown" to get out of the study early. This prisoner was replaced with one of the alternates.

Results

By the end of the study, the guards had won complete control over all of their prisoners and were using their authority to its greatest extent. One prisoner had even gone as far as to begin a hunger strike. When he refused to eat, the guards put him into solitary confinement for three hours (even though their own rules stated the limit that a prisoner could be in solitary confinement was only one hour). Instead of the other prisoners considering this inmate as a hero and following along in his strike, they chanted together that he was a bad prisoner and a troublemaker. Prisoners and guards had adapted rapidly to their roles, doing more than had been predicted and resulting in dangerous and potentially psychologically damaging situations. Zimbardo himself started to give in to the roles of the situation. He had to be shown the reality of the study by Christina Maslach, his girlfriend and future wife, who had just received her doctorate in psychology. Zimbardo stated that the message from the study is that "situations can have a more powerful influence over our behaviour than most people appreciate, and few people recognize [that]."

At the end of the study, after all the prisoners had been released, everyone was brought back into the same room for evaluation and to be able to get their feelings out in the open towards one another.