On a mid-August morning in the late summer of 1971, Palo Alto police cars were spread across the city picking up a predetermined number of college students throughout the small California town. They were arrested for armed robbery or burglary, booked and fingerprinted at the local police station, blindfolded, and then swiftly brought to the nearby Stanford County Prison. It was a harrowing scene, but none of it was real. Until it was.

The students picked up that day were willing participants in the Stanford Prison Experiment, perhaps the most infamous study in the history of social psychology. In it, 18 students were randomly selected to assume the roles of prisoners or guards and to be monitored 24/7 at a fake prison in the basement of Stanford University’s Jordan Hall, under the supervision of lead psychologist and professor Philip Zimbardo, who acted as the prison’s “superintendent.” All participants would be paid a then-significant sum of $15 per day.

The guards, given little instruction on how to manage the prisoners, eventually started psychologically and then physically abusing the prisoners a mere day after the study began, at which point the study devolved into an extreme, unrestrained Lord of the Flies-type situation. Zimbardo, 38 at the time, and his cohort remained willing bystanders to the increasingly depraved behavior. The experiment was scheduled to last two weeks, but was abruptly cancelled after only six days.

It’s now the subject of a new film to be released this week — a dramatic re-telling and not a documentary — called The Stanford Prison Experiment, and it brings to light once more the controversial gray areas surrounding what happened and the polarizing figurehead behind it all: Zimbardo himself, who has been involved in bringing the story of the experiment to the silver screen for decades. “There have been many scripts, many iterations,” Zimbardo told me when I met with him to talk about the study and the new movie. “I’ve been working on this film for 35 years.”

For better or worse, Zimbardo is an opportunist first and an educator second, who has ridden the prison experiment’s notoriety for the rest of his career. Though according to him there was “zero” fallout from the experiment immediately after it was ended, its scientific intentions using a group of innocent kids gave way to an unethical but revealing conclusion about human nature that gained fame following a series of actual prison riots at San Quentin and Attica in the 1970s.

He is a personable, sometimes kooky, presence and carries the air of a P.T. Barnum-esque showman. He also legitimately believes in the worth of what happened — despite the fact that it was totally unethical and could never be rightfully recreated, except in a movie like this.

Zimbardo (right) and actor Billy Crudup, who portrays him in the film

Yet during our interview he was willing to admit fault. “I was gradually being transformed by my role of prison superintendent. That was the big mistake,” he said. “I should have had somebody else do that.” He says his personal involvement and the problems that arose weren’t all on him. “The other problem was as a researcher I seriously underestimated the size of a team you need to run this kind of research. It was four people: me, two graduate students, and an undergrad.”

When one of the team dropped out, three people — including Zimbardo — were working around the clock to supervise each of the 12 people in the experiment at a given time. “We were all over-stressed, and unaware,” he said. “I was trapped in the experiment.”

This sort of sentiment typifies Zimbardo’s relationship to what happened. He understands that what went down under his supervision was bad, even realizing it during the experiment itself. Yet he was the one who fostered the behavior of the allegedly autonomous guards to make it that way. Everything that went wrong with the experiment can be traced to his influence, even his instructions.

Carlo Prescott, the former San Quentin prisoner who helped Zimbardo and his team create the Stanford Prison’s atmosphere, questioned the experiment in retrospect, “How can Zimbardo … express horror at the behavior of the ‘guards’ when they were merely doing what Zimbardo and others, myself included, encouraged them to do at the outset or frankly established as ground rules?” Later, he defeatedly said: “I blew it. I became an unwitting accomplice to a theatrical exercise that conveniently absolves all comers of personal responsibility for their abominable moral choices.

John Mark, one of the “guards,” told the Stanford Alumni magazine in 2011 what he thought of Zimbardo’s contradictions, “Throughout the experiment, he knew what he wanted and then tried to shape the experiment — by how it was constructed, and how it played out — to fit the conclusion that he had already worked out.”

These statements point out one of the main criticisms that have been leveled at Zimbardo as the experiment has gained its infamy over the years: Could these normal, healthy kids have had an innate ability to become monsters, or was there something — or someone — influencing them?

Boston College professor Peter Gray posed this question in Psychology Today magazine, “What would have happened if Zimbardo had said to the guards, at the outset, that the purpose of the experiment was to prove that it is possible to be both a guard and a decent human being, or in some way implied that the goal was to prove that guards can be kind?”

It becomes obvious that by being involved, Zimbardo may have willingly steered the experiment towards its controversial end.

Gray also put his criticism more succinctly, “This is a study of prisoners and guards, so their job clearly is to act like prisoners and guards — or, more accurately, to act out their stereotyped views of what prisoners and guards do,” he said. “Surely, Professor Zimbardo, who is right there watching them (as the Prison Superintendent) would be disappointed if, instead, they had just sat around chatting pleasantly and having tea.”

Zimbardo himself admitted to me that had things not escalated, the study would have ended. “At the end of day one I said, ‘Forget it, nothing is happening.’” But as soon as the prisoners began fighting back against the cruel behavior, which escalated into a nine person mini-riot, he knew he had something. “Literally, if the revolt had not happened, I would have ended the second day and said ‘There’s nothing here.’”

Zimbardo, who acted as a consultant on the film, gladly defends its narrative against what really happened. “I’d say the movie itself is a very faithful rendition of the Stanford Prison Experiment as it happened,” he said. “I would say if you had to give a number it’s about 90 percent right-on. There are a few places where obviously the director took poetic license, but all the dialogue [in the film] between prisoners and guards is exactly what happened.”

To him, the best reason to make a fictional film out of the experiment is to educate and to find some sort of legitimate point of view from these mistakes. Though a recent study found that out of 13 introductory psychology textbooks that mentioned the experiment, only six explained its less than proper methods. Despite the fact that there are relative treasure troves of source materials about the experiment available (you can start with Stanford’s own collection here), maybe the movie will allow more people than ever to decide for themselves how wrong or how right it was.

I asked him why he didn’t stop the experiment when it escalated out of control. “That, I feel guilty about,” he said. “That is a mistake. But again, it’s a testimony to what the experiment was trying to demonstrate. It’s the power of situations to overwhelm good intentions, moral conscious, and character in kids but also sophisticated grownups.” Then he added, “And I feel guilty and sorry about that.”

Zimbardo himself continues to somewhat reluctantly benefit from its infamy, especially when situations like the Abu Ghraib prison scandal add more credence to the experiment’s psychological truths. The movie is worth seeing simply to get a sense of how all this craziness went down and as a reminder of how situational your ethics may truly be.

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