By the end, Ma was really concerned with what the hell happened to the professor in charge. She was saying, “Let’s dox that piece of shit! I hate this guy!” And then she took a sip of her coffee. She’s 87, so I just waited a few minutes, and then she ran out of passion to kill a professor.
“He’s not very nice.”
Stanford Prison Experiment
1. August 14th, 1971: What Is the Stanford Prison Experiment?
Stanford psychologist Philip Zimbardo creates a simulated prison in the basement of the university’s psychology building.
Twenty-four young men have been selected from more than 70 volunteers after psychological screening.
They are randomly assigned to be either prisoners or guards.
They are being paid $15 a day, which was a meaningful amount of money for college students in 1971.
The study is intended to examine whether behavior is primarily shaped by personality or situation.
The experiment is scheduled to last approximately two weeks. It will actually last six days.
The prisoners do not know that the following day, August 15th, some of them will be subjected to surprise mock arrests.
2. Why Would Anyone Volunteer for a Prison Experiment?
The original newspaper advertisement described the study as research into “prison life” and offered $15 per day.
More than 70 people responded, giving researchers a surprisingly large pool from which to select participants.
The applicants were screened for psychological and physical health.
The final participants were considered relatively ordinary, healthy young men.
They were randomly assigned to their roles, which was important to Zimbardo’s argument that personality alone could not explain what happened.
There is an interesting question before the experiment even begins: Who volunteers to spend two weeks pretending to be in prison?
The participants were not professional actors or people accustomed to prison environments. They were college students who thought they were signing up for a psychological study.
3. The Arrest
On August 15th, the students assigned to be prisoners are unexpectedly arrested.
Palo Alto police officers cooperate with the researchers, and the arrests are made to resemble actual arrests.
The students are handcuffed, searched, taken to the police station, fingerprinted and photographed.
They are then transported to Stanford and processed into the simulated prison.
The researchers deliberately wanted to strip away the feeling that this was simply a game or classroom exercise.
The prisoners had volunteered for an experiment, but suddenly they were experiencing many of the rituals associated with actual incarceration.
The use of real police officers is also one of the early examples of how far Zimbardo was willing to go to make the experiment feel authentic.
4. The Guards
The guards receive uniforms, wooden clubs, whistles and sunglasses, while the prisoners are given uniforms and identification numbers.
The guards are told that they have considerable control over the prisoners, although they are not supposed to physically harm them.
The guards behave differently from one another. Some are relatively passive, while others become much more aggressive.
David Eshelman, one of the most aggressive guards, later said that he consciously developed a particularly harsh persona because he believed that was what the experiment required.
That detail is important because it complicates the famous interpretation that the situation simply transformed ordinary people into abusive authority figures.
The guards were not all behaving the same way, even though they were all placed in the same situation.
5. The Prisoners
The prisoners respond differently as well. Some resist, some become withdrawn, and some experience significant emotional distress.
Douglas Korpi has one of the most dramatic breakdowns in the experiment and is released early.
Korpi later disputed the interpretation of his breakdown, saying that he was trying to get himself released because he needed to get back to studying for an examination.
The prisoners also stage a rebellion early in the experiment, barricading themselves in their cells and refusing to cooperate.
The guards respond by attempting to regain control, turning the situation into an actual confrontation between the two groups.
The differences among the prisoners are just as interesting as the differences among the guards because they challenge the idea that everyone simply surrendered to their assigned role.
6. Zimbardo Becomes Part of the Experiment
Zimbardo does something that is now one of the most heavily criticized aspects of the study: he becomes the superintendent of the prison.
He is therefore both the principal researcher and a participant in the institutional environment he is studying.
Rather than observing a prison from outside, he becomes invested in keeping the prison functioning.
Later critics argued that this made it difficult for him to remain objective about what was happening.
Zimbardo himself eventually acknowledged that he became deeply immersed in the situation and lost some perspective.
The question is not simply whether the guards were influenced by the situation. It is also whether the researchers were influenced by the situation they had created.
7. Christina Maslach and the Six-Day Experiment
The study is designed to last roughly two weeks but is terminated after only six days.
Prisoners are experiencing significant psychological distress, while some guards have become increasingly aggressive and humiliating.
Christina Maslach, a psychologist who visits the prison, is reportedly shocked by what she sees.
She challenges Zimbardo about the morality of continuing the experiment.
Zimbardo later identified her reaction as an important moment in his realization that the experiment had gone too far.
The study officially ends on August 20th, 1971.
The fact that the experiment ended eight days early is central to the story. The researchers weren’t looking at a theoretical possibility anymore. They were dealing with actual people becoming distressed in front of them.
8. What Were the Researchers Actually Telling the Guards?
The classic version of the Stanford Prison Experiment suggests that the guards spontaneously became abusive simply because they were given power.
Later researchers examined the surviving recordings, documents and interviews and found evidence that the research team gave guards instructions about maintaining control and creating feelings of powerlessness.
In one recorded briefing, guards were told they could create boredom, frustration and fear, although Zimbardo has strongly disputed the characterization that he instructed them to be cruel.
This distinction matters enormously to the scientific interpretation.
If the guards were simply given power and independently became cruel, that supports one conclusion.
If they were given expectations about how prison guards should behave and then acted accordingly, that supports a very different conclusion.
Thibault Le Texier’s 2019 research was particularly influential in bringing these questions back into the discussion.
9. How the Stanford Prison Experiment Became a Legend
The experiment became one of the most famous studies in psychology and was repeatedly presented as evidence that ordinary people can become abusive when placed in powerful institutional roles.
The basic story is incredibly memorable: good people, bad situation, terrible behavior.
It appeared in psychology textbooks and became part of popular discussions about prisons, military organizations, policing, authority and institutional abuse.
Zimbardo became a major public figure partly because of the experiment and spent decades explaining and defending its significance.
But the famous version became considerably simpler than the actual history.
Later criticism did not merely question individual details. It challenged whether the experiment actually demonstrated the sweeping conclusion that became attached to it.
The experiment therefore became famous not only for what happened in the basement, but for the way a complicated scientific study was transformed into a very simple story about human nature.
10. So What Did the Stanford Prison Experiment Actually Prove?
The experiment unquestionably demonstrated that a group of young people placed into a highly artificial prison environment could produce intense conflict, distress and differences in behavior within a very short period.
What remains controversial is why that happened.
Zimbardo’s interpretation emphasized the power of situations, authority and institutional roles.
Later researchers have argued that participant expectations, researcher instructions and Zimbardo’s own involvement played a much larger role than the classic account acknowledged.
The study also became an important example of the problems that can arise when researchers become too involved with their subjects and when a compelling result begins to acquire a life of its own.
There is a legitimate distinction between saying “the experiment was flawed” and saying “nothing interesting happened.” Those aren’t the same claim.
More than half a century later, the Stanford Prison Experiment remains fascinating precisely because the argument has shifted from “Can ordinary people become monsters?” to a much more complicated question: “When people behave differently under pressure, how do we figure out what actually caused the change?”