The Stanford Prison Experiment 40 Years Later

The Stanford Prison Experiment, conducted by Philip Zimbardo in August of 1971 at Standford University, is one of the most discussed - and most notorious - research projects in modern psychology. Forty years after the fact, Stanford Magazine talks to some of the key figures in the project about their memories and experience.

Here is a brief summary of the study from the website (linked to above):

Welcome to the Stanford Prison Experiment web site, which features an extensive slide show and information about this classic psychology experiment, including parallels with the abuse of prisoners at Abu Ghraib. What happens when you put good people in an evil place? Does humanity win over evil, or does evil triumph? These are some of the questions we posed in this dramatic simulation of prison life conducted in the summer of 1971 at Stanford University.

How we went about testing these questions and what we found may astound you. Our planned two-week investigation into the psychology of prison life had to be ended prematurely after only six days because of what the situation was doing to the college students who participated. In only a few days, our guards became sadistic and our prisoners became depressed and showed signs of extreme stress. Please join me on a slide tour describing this experiment and uncovering what it tells us about the nature of human nature.

- Philip G. Zimbardo

With that background, here is the article from Stanford Magazine:

The Menace Within

What happened in the basement of the psych building 40 years ago shocked the world. How do the guards, prisoners and researchers in the Stanford Prison Experiment feel about it now?

By Romesh Ratnesar

Stanford Prison Experiment

It began with an ad in the classifieds.

Male college students needed for psychological study of prison life. $15 per day for 1-2 weeks. More than 70 people volunteered to take part in the study, to be conducted in a fake prison housed inside Jordan Hall, on Stanford's Main Quad. The leader of the study was 38-year-old psychology professor Philip Zimbardo. He and his fellow researchers selected 24 applicants and randomly assigned each to be a prisoner or a guard.

Zimbardo encouraged the guards to think of themselves as actual guards in a real prison. He made clear that prisoners could not be physically harmed, but said the guards should try to create an atmosphere in which the prisoners felt "powerless."

The study began on Sunday, August 17, 1971. But no one knew what, exactly, they were getting into.

Forty years later, the Stanford Prison Experiment remains among the most notable—and notorious—research projects ever carried out at the University. For six days, half the study's participants endured cruel and dehumanizing abuse at the hands of their peers. At various times, they were taunted, stripped naked, deprived of sleep and forced to use plastic buckets as toilets. Some of them rebelled violently; others became hysterical or withdrew into despair. As the situation descended into chaos, the researchers stood by and watched—until one of their colleagues finally spoke out.

The public's fascination with the SPE and its implications—the notion, as Zimbardo says, "that these ordinary college students could do such terrible things when caught in that situation" —brought Zimbardo international renown. It also provoked criticism from other researchers, who questioned the ethics of subjecting student volunteers to such extreme emotional trauma. The study had been approved by Stanford's Human Subjects Research Committee, and Zimbardo says that "neither they nor we could have imagined" that the guards would treat the prisoners so inhumanely.

In 1973, an investigation by the American Psychological Association concluded that the prison study had satisfied the profession's existing ethical standards. But in subsequent years, those guidelines were revised to prohibit human-subject simulations modeled on the SPE. "No behavioral research that puts people in that kind of setting can ever be done again in America," Zimbardo says.

The Stanford Prison Experiment became the subject of numerous books and documentaries, a feature film and the name of at least one punk band. In the last decade, after the revelations of abuses committed by U.S. military and intelligence personnel at prisons in Iraq and Afghanistan, the SPE provided lessons in how good people placed in adverse conditions can act barbarically.

The experiment is still a source of controversy and contention—even among those who took part in it. Here, in their own words, some of the key players in the drama reflect on their roles and how those six days in August changed their lives.

The Superintendent

Phil Zimbardo
Zimbardo joined Stanford's psychology department in 1968 and taught there until his retirement in 2007.

The study was focused originally on how individuals adapt to being in a relatively powerless situation. I was interested in prisoners and was not really interested in the guards. It was really meant to be a single, dramatic demonstration of the power of the situation on human behavior. We expected that we would write some articles about it and move on.

Phil Zimbardo

After the end of the first day, I said, "There's nothing here. Nothing's happening." The guards had this antiauthority mentality. They felt awkward in their uniforms. They didn't get into the guard mentality until the prisoners started to revolt. Throughout the experiment, there was this conspiracy of denial—everyone involved was in effect denying that this was an experiment and agreeing that this is a prison run by psychologists.

There was zero time for reflection. We had to feed the prisoners three meals a day, deal with the prisoner breakdowns, deal with their parents, run a parole board. By the third day I was sleeping in my office. I had become the superintendent of the Stanford county jail. That was who I was: I'm not the researcher at all. Even my posture changes—when I walk through the prison yard, I'm walking with my hands behind my back, which I never in my life do, the way generals walk when they're inspecting troops.

We had arranged for everyone involved—the prisoners, guards and staff—to be interviewed on Friday by other faculty members and graduate students who had not been involved in the study. Christina Maslach, who had just finished her PhD, came down the night before. She's standing outside the guard quarters and watches the guards line up the prisoners for the 10 o'clock toilet run. The prisoners come out, and the guards put bags over their heads, chain their feet together and make them put their hands on each other's shoulders, like a chain gang. They're yelling and cursing at them. Christina starts tearing up. She said, "I can't look at this."

I ran after her and we had this argument outside Jordan Hall. She said, "It's terrible what you're doing to these boys. How can you see what I saw and not care about the suffering?" But I didn't see what she saw. And I suddenly began to feel ashamed. This is when I realized I had been transformed by the prison study to become the prison administrator. At that point I said, "You're right. We've got to end the study."

[As the study was underway], there was an escape attempt at San Quentin prison and [former Black Panther] George Jackson was shot and killed. Three weeks after that, there's the Attica prison riot [in New York]. Suddenly, prisons are hot. Two government investigative committees start hearings and I'm flown out to Washington to present to a congressional subcommittee on the nature of prisons. I went from knowing nothing firsthand about prisons to being an expert. But I worked hard to learn more. I visited a number of correctional facilities all over the country. I organized a program for Stanford students to teach a course at a prison. For years I had an active correspondence with at least 20 different prisoners.

It wasn't a formal experiment. My colleagues probably never thought much of it. But as a result of the prison study, I really became more aware of the central role of power in our lives. I became more aware of the power I have as a teacher. I started consciously doing things to minimize the negative use of power in the classroom. I encouraged students to challenge me.

I think I became more self-reflective. I'm more generous and more open because of that experience. I think it made me a better person.

There is much more from other principles in the experiment, but I want to include one of the prisoners (they only spoke to one for this article):

The Prisoner

Richard Yacco
A community college student at the time, Yacco helped instigate a revolt against conditions in Zimbardo's prison. He was released one day early from the study after exhibiting signs of depression. After working in radio and television production, he now teaches at a public high school in Oakland.

At the time I was debating: If I were drafted to fight in Vietnam, what would I do? Would I be willing to go to jail? Since that was one of the considerations, I thought, well, a prison experiment would give me some insight into what that would be like.

The first thing that really threw me off was the sleep deprivation. When they woke us up the first time, I had no idea it was after only four hours of sleep. It was only after they got us up and we did some exercises and then they let us go back to bed that I realized they were messing with our sleep cycles. That was kind of a surprise from the first night.

Toni Gauthier

I don't recall exactly when the prisoners started rebelling. I do remember resisting what one guard was telling me to do and being willing to go into solitary confinement. As prisoners, we developed solidarity—we realized that we could join together and do passive resistance and cause some problems. It was that era. I had been willing to go on marches against the Vietnam war, I went on marches for civil rights, and was trying to figure out what I would do to resist even going into the service. So in a way I was testing some of my own ways of rebelling or standing up for what I thought was right.

My parents came on visitors' night. They were really concerned with the way I looked. I told them that they're breaking up our sleep, that we weren't having the chance to take showers. My appearance really concerned both of my parents, my mother especially.

When I asked [Zimbardo's team] what I could do if I wanted to quit, I was told, "You can't quit—you agreed to be here for the full experiment." That made me feel like a prisoner at that point. I realized I had made a commitment to something that I now could not change. I had made myself a prisoner.

I ended up being paroled by the "parole board." They released me Thursday night. That's when they told me they were going to end the experiment the next day. What I learned later is that the reason they chose me [to parole] is because they thought I'd be the next guy to break down. I was surprised, because I never thought I was going through any kind of depression or anything like that.

PARENTAL GUIDANCE: Zimbardo met with parents of the prisoners to address concerns about conditions and the prisoners' mental states. Stanford Prison Experiment

One thing that I thought was interesting about the experiment was whether, if you believe society has assigned you a role, do you then assume the characteristics of that role? I teach at an inner city high school in Oakland. These kids don't have to go through experiments to witness horrible things. But what frustrates my colleagues and me is that we are creating great opportunities for these kids, we offer great support for them, why are they not taking advantage of it? Why are they dropping out of school? Why are they coming to school unprepared? I think a big reason is what the prison study shows—they fall into the role their society has made for them.

Participating in the Stanford Prison Experiment is something I can use and share with students. This was one week of my life when I was a teenager and yet here it is, 40 years later, and it's still something that had enough of an impact on society that people are still interested in it. You never know what you're going to get involved in that will turn out to be a defining moment in your life.

Tags: Psychology, prisons, authoritarian, research, trauma, The Stanford Prison Experiment, 40 Years Later, social psychology, Philip Zimbardo, prisoners, guards, cruelty, behavioral research, The Menace Within, Stanford Magazine, Romesh Ratnesar