What Philip Zimbardo and the Stanford Prison Experiment Tell Us About Abuse of Power

Updated | The prisoners marched with bags on their heads and chains on their legs, like a chain gang, for an evening "toilet run." It was 10 p.m., the last opportunity they would have to use a restroom until morning, save for a bucket in their cells. Sometimes, to add an element of further humiliation, the guards wouldn't let them empty their makeshift bedpan.

Worst of all, this didn't occur in an actual prison, but in a simulation. The prisoners and the guards were college students, all of whom had replied to a nondescript classified ad: "Male college students needed for psychological study of prison life. $15 per day for 1-2 weeks."

In the summer of 1971, a team of Stanford University researchers led by Philip Zimbardo set out to study prison psychology. The team wanted to learn what happens to people when they become prisoners or guards. Of the some 70 male students who applied for the study, the team eventually selected 24—after a careful vetting process that ensured mental and physical health without any history of crime or substance abuse—assigning half of them the role of prisoner and the other half the role of guard.

The participants were placed in a simulated prison environment, located in the basement of Stanford's psychology department building. Of the two dozen picked, the researchers started the study with nine guards and nine prisoners, with the rest reserved as potential alternates. Zimbardo had to end what should have been a one- to two-week experiment after the sixth day. Participants in the role of guard quickly descended into abject sadism—depriving prisoners of beds, stripping them naked, marching them on those toilet runs.

The takeaway from Zimbardo's Stanford Prison Experiment? Evil environments in which those in power can do whatever they want to the powerless without fear of reprisal—like prison—can corrupt even normal, educated, healthy people. The test, called the Stanford Prison Experiment, remains a staple of psychology coursework and training for the armed forces.

It's also the title of a new film that chronicles the controversial study. The Stanford Prison Experiment, released July 17, with Billy Crudup in the role of Philip Zimbardo, hits a hauntingly poignant note at a time when the United States has had to confront hard questions about what it means to be a protector or a civilian. Zimbardo, professor emeritus at Stanford University and author of The Lucifer Effect: Understanding How Good People Turn Evil, worked extensively with The Stanford Prison Experiment screenwriter Tim Talbott and director Kyle Alvarez to ensure the film accurately portrayed the study.

Dr. Zimbardo spoke with Newsweek about the cinematic portrayal of his experiment—and why good guys can go so bad.

Are you satisfied with how the movie portrayed the experiment and the psychological toll on the prisoners and guards?
I'm very impressed with everything about the movie—the quality of the acting, the writing, the directing especially. And the movie is 99 percent right-on accurate…. One of the reasons that the movie is so accurate is I worked with the screenwriter, Tim Talbott, when I was writing about the details of the Stanford Prison Experiment in The Lucifer Effect…. What I did was I went back and made typescripts of 12 hours of the videos that we had taken during the study.... All of the interactions between prisoners and guards are exactly, word for word, what happened.

Would you say you're more satisfied with this than some of the other documentaries that have been made about the experiment?
I am 100 percent satisfied. I mean, the worst thing in the world was the German movie Das Experiment. It had nothing to do with the study. The prisoners and guards are a bunch of old men—you know, 30, 40 years old. The guards kill prisoners. The prisoners kill the guards. The guards rape a female psychologist. The study was bad enough in terms of the psychological pressure. None of that even approached [Das Experiment].

And also there was a BBC documentary which was also foolish because the prisoners took over the prison, and the guards had to follow the prisoners' rules. So those were really stupid recreations. This is as accurate as a recreation could be, but the bottom line is it's a good movie. It's not a documentary—it's a docudrama.

Do you think the meaning and reception of the movie will be different in this cultural climate, where everyone is talking about prison reform and police reform?
The release of the movie had nothing to do with current events. I mean, the key was getting it into Sundance. All the stuff about police abuse around the country, police abuse of blacks, was around [before] and subsequent to it. I think the movie will stimulate new discussions about the need to train policemen better, the need to train prison guards better, to avoid inevitable abuses. The study is really about what happens when you give some people total power over others, even when they all know they're playing a role. It's not reality. The role becomes real.

But again, if you think about it, prison guards and policemen are playing a role. That's not who they are. You know, they're "Bill Johnson," who works at a police department in Baltimore or New York, or something, and you get in that setting, and the other guards, the other policemen say, "Hey, this is the way we do things around here," and you're part of a culture. Sometimes the culture is a culture of racism; sometimes the culture is a culture of domination, etc.

What it is about these systems that makes people act like this?
The overarching thing is, What do you imagine would happen if you put really good people—smart and talented and psychologically healthy, physically healthy people—in a really bad place, a place which is dominated by power and authority where there's limited oversight? Do you think that the good people would change the nature of the bad place, or is there something powerful about evil situations—or what I call bad barrels—that would come to change the good people so they do bad things? I'd like to use the metaphor of what happens if you have a bad barrel and you fill it with good apples. Do the good apples change the bad barrel, or do bad barrels change a good apple?

From your perspective, if there are these institutions where there are going to be these roles—there can't be a prison without guards, there can't be a society without police—how do you train them so that these roles do not spin into something violent and abusive?
There should be outside observers who come in randomly to see what's happening and have the power to blow the whistle and say, "This is abuse, not treatment." You can limit the potential for abuse of power by having people who have higher power—people who run this system to be able to observe through video cameras, through random surveillance, and then set the rules and say, "This is unacceptable. You cannot hit prisoners. You cannot curse them. You cannot use racial comments."

This interview has been edited slightly for length and clarity.

Update: This article has been updated to include Dr. Zimbardo's title.