Professor Philip Zimbardo: The Interview


Stanford Psychology Professor Philip Zimbardo graciously agreed to take time from his hectic speaking, writing and teaching schedule to provide Hans Sherrer with his personal insights into the Stanford Prison Experiment he created and supervised. Professor Zimbardo answered questions by Hans Sherrer on August 27, 2003.


Question by Hans Sherrer (HS): Professor Zimbardo, was the Stanford Prison Experiment (SPE) the first psychology experiment that attempted to simulate a prison environment?


Answer by Professor Zimbardo (PZ): I am not sure, but it was the first to create a live in prison-like environment for an extended time period of at least a week.



HS: When did you first conceive the idea of observing the behavior of mock prisoners and guards in a simulated prison?


PZ: During a class the previous spring when I got students interested in the intersection of psychology of individuals and the sociology of institutions, and doing a  mock prison for a weekend was part of the class exercise for one group of social psychology students.



HS: Did you encounter any opposition from the administration at Stanford University when you proposed the idea of conducting the SPE?


PZ: None. The study was  readily approved by the Human Subjects Research committee because it seemed like college kids playing cops and robbers, it was an experiment that anyone could quit at any time and minimal safeguards were in place. You must distinguish hind sight from fore sight, knowing what you know now after the study is quite different from what most people imagined might happen before the study began.



HS: The SPE was conducted in the basement of Stanford’s Psychology Building that was remodeled into the Stanford County Prison (SCP). Did you have any advisors with prison experience assist in designing the experiment to be as realistic as possible?


PZ: Yes, I taught a course that summer on the psychology of imprisonment with an ex-convict, Carlo Prescott, recently released from San Quentin after nearly 15 continuous years in various California prisons. He also was my consultant throughout the study, and I relied on others, guards, prison chaplain, local police and other ex-convicts.



HS: How many people assisted in operating the Stanford County Prison, and were they students, faculty members or outside volunteers?


PZ: I was the Superintendent, there was a Warden, an undergraduate, and 2 graduate students who acted as my Lieutenants. We also had the tech services of the Psychology Department’s technician, and a few other people played minor roles. There were no outside volunteers



HS: When the SPE began what were the two or three primary things you hoping to learn from observing mock prisoners and guards interacting for two-weeks in a simulated prison environment?


PZ: What happens when good people are put into an evil place, do they triumph or does the situation come to dominate their past history and morality?


How powerful are situational forces in seducing ordinary people into ego-alien behaviors?


What are the boundaries between illusion and reality in such a setting?



HS: When the experiment began, did you expect the mock guards and prisoners to pretend to be their assigned role for the duration of the experiment?


PZ: We did not know if they would get into their roles and stay in them or it would just be fun and games to them.



HS: When did it become apparent that the guards and prisoners were not acting, but had conformed to becoming the role they started out pretending to be?


PZ: The major change came on the second morning when the prisoners rebelled and the guards crushed their rebellion with force and that led them to take their roles more seriously and to perceive of the prisoners as dangerous.



HS: The SPE was stopped after six days when a woman who hadn’t previously observed the SCP was shocked at the behavior of the guards and prisoners. She was able to convince you to stop the experiment. Have you given thought to how long you would have continued the experiment if she had not visited the SCP, and what would it have taken for you to have stopped the experiment on your own without prodding from a concerned outsider?



PZ: I believe I would have ended it in a few more days because it was obvious that the guards were totally dominating the prisoners and creating horrific conditions, night after night escalating the kinds of abuse and degradation. The role as an outsider was to reframe the conditions that we

had adapted to as immoral and terrible.



HS: By the time you stopped the SPE after six days, four prisoners had been released due to what have been described as psychological breakdowns. Were there other reactions by guards or prisoners that influenced your decision to stop the experiment at that time?


PZ: Another prisoner broke out in a full body psychosomatic rash and had to be released. The remaining prisoners were acting like zombies, totally  mindlessly obedient, and some guards were becoming creatively evil in their tormenting actions.



HS: What do you think are some of the SPE’s most important findings?


PZ: Situational variables can exert powerful influences over human behavior, more so that we recognize or acknowledge.


Seemingly small features of situations, like roles, rules, uniforms, signs, group identity, can come to control behavior as much as dispositional variables, such as traits.


Human behavior is incredibly pliable, plastic.


The line between good and evil is permeable and almost anyone can be induced to cross it when pressured by situational forces.


Heroes are those who can somehow resist the power of the situation and act out of noble motives, or behave in ways that do not demean others when they easily can.


Evil is knowing better, but willingly doing worse.



HS: Thank you for your time Professor Zimbardo, and thank you for your efforts that have made millions of people around the world aware of the Stanford Prison Experiment’s important findings.



Comments on the Interview with Stanford University Psychology Professor Philip Zimbardo


by Hans Sherrer


          Professor Zimbardo makes it clear in his interview that when the Stanford Prison Experiment (SPE) began he didn’t know how the several dozen psychologically normal people involved would react. Yet even though he was expecting the unexpected, he was taken off guard when less than 24-hours into the experiment the “situational forces” of being in a prison environment caused the “normal” people participating to become guards and prisoners, and his staff and him to become prison administrators. So a critical finding of the experiment is how pliable and plastic a person’s behavior is to being shaped by the circumstances of a situation. As Professor Zimbardo notes, a situation can have as much effect on a person’s behavior as their personality traits. That principle is as applicable to the behavior of a person during their imprisonment as it is prior to and after it, when they are in the “free” world.

          The results of Professor Zimbardo’s 1971 prison experiment have been publicized for over 30 years in professional journals, popular magazines and books, and it was the inspiration for a simulated prison experiment in Australia in the late 1970s, and another in England televised nationally by the BBC in 2002. The experiment is also publicized by the professor’s many speaking engagements in this and other countries, and the SPE’s official website gets over 4 million unique visitors yearly. An example of the widespread knowledge of the SPE is it can be brought up as a topic of conversation in coffee shops, book stores and other public places, and invariably one or more people has heard of it.

          So it is reasonable to suppose a significant number of law enforcement professionals, judges and politicians are aware of the SPE. It is also reasonable to think those people would have some awareness that if the “situational forces” of their life was different, they would be amongst those caged in a prison instead of being on the outside looking in. Yet that knowledge is not being used to guide the shape of federal and state criminal codes, or of sentencing policies and imprisonment practices so that they primarily focus on providing educational opportunities, physical care, vocational training, enhanced social skills, and prison release support services to people who are imprisoned.

          Novelist Fyodor Dostoyevsky, who spent five years imprisoned in Siberia after having his death sentence commuted by the Czar, is credited with the insight that “Compassion is the chief law of human existence.” So in the spirit of calling a spade a spade, it is my observation and not Professor Zimbardo’s, that the widespread awareness of the SPE’s findings indicates that innumerable legislators, judges, prosecutors, probation officials and prison administers could be considered to meet his definition of being evil -- “Evil is knowing better, but willingly doing worse.” Those people know better than to be a willing participant in this country’s federal and state law enforcement conveyor belt that generates millions of “convicts” that are denied the compassion necessary to assist them to get off the treadmill.

          So an unintentional legacy of the SPE is it revealed the poetic justice of Arthur Koestler’s Darkness at Noon (1940). That fact based novel depicts how in the 1930s, government officials in Soviet Russia were faced with the “situational force” of suddenly having the tables turned by being considered and treated as criminals. Law enforcement officials, judges and politicians in this country are deserving of that same poetic justice. (NOTE: Darkness at Noon was recently rated in The Guardian newspaper (London, UK) as the 3rd most important political novel of the 20th century.)