Working draft:

Another unexpected outcome?


"What happens when you put good people in an evil place? Does humanity win over evil, or does evil triumph?" (Zimbardo,

In a simulation of prison life, Stanford students "played" in the roles of "guards" and "prisoners." The 24 subjects were healthy, young, intelligent, middle-class males. They had been given diagnostic interviews and personality tests to eliminate candidates with psychological problems. (Just what tests? Anyhow, presumably more than usual for prison guards, and prisoners?) They were randomly assigned to the roles of prisoner and guard.

The "prisoners" were rounded up by actual police (a curious and somewhat questionable action?), Mirandized, strip searched, de-loused, head shaved, blindfolded, and then "imprisoned" in a numbered uniform with a chain around the ankle. The uniform was actually a dress, without underwear. "The guards were given no specific training on how to be guards. Instead they were free, within limits, to do whatever they thought was necessary to maintain law and order in the prison and to command the respect of the prisoners. The guards made up their own set of rules, which they then carried into effect under the supervision of Warden David Jaffe, an undergraduate from Stanford University. They were warned, however, of the potential seriousness of their mission and of the possible dangers in the situation they were about to enter, as, of course, are real guards who voluntarily take such a dangerous job." (Zimbardo,

Guards were all dressed in khaki uniforms, with a whistle, billy club, and mirror sunglasses. The whistles were blown periodically for a count-off, with prisoners shouting out their numbers. Push-ups were sponataneously adopted by the guards as one form of discipline.

To quell an uprising by the prisoners, guards used a fire extinguisher which shot a stream of skin-chilling carbon dioxide, and they forced the prisoners away from the doors. (The fire extinguishers were present in compliance with the requirement by the Stanford Human Subjects Research Panel, which was concerned about potential fire threats. Oh irony).

When one prisoner broke down, the experimenters didn't believe it, and kept him going. When parents visited, the experimenters cleaned up the cells and guards, and made the parents sign in and restricted them to a brief visitation, as in a real prison.

"When one mother told me she had never seen her son looking so bad, I responded by shifting the blame from the situation to her son. "What's the matter with your boy? Doesn't he sleep well?" Then I asked the father, "Don't you think your boy can handle this?" He bristled, "Of course he can -- he's a real tough kid, a leader." Turning to the mother, he said, "Come on Honey, we've wasted enough time already." And to me, "See you again at the next visiting time." (Zimbardo,

"At one point in the study, I invited a Catholic priest (an actual priest!)who had been a prison chaplain to evaluate how realistic our prison situation was, and the result was truly Kafkaesque. The chaplain interviewed each prisoner individually, and I watched in amazement as half the prisoners introduced themselves by number rather than name. After some small talk, he popped the key question: "Son, what are you doing to get out of here?" When the prisoners responded with puzzlement, he explained that the only way to get out of prison was with the help of a lawyer. He then volunteered to contact their parents to get legal aid if they wanted him to, and some of the prisoners accepted his offer." (Zimbardo,

"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." (Zimbardo,

"Christina Maslach, a recent Stanford Ph.D. (presently known for work on stress and burnout) brought in to conduct interviews with the guards and prisoners, strongly objected when she saw our prisoners being marched on a toilet run, bags over their heads, legs chained together, hands on each other's shoulders. Filled with outrage, she said, "It's terrible what you are doing to these boys!" Out of 50 or more outsiders who had seen our prison, she was the only one who ever questioned its morality. Once she countered the power of the situation, however, it became clear that the study should be ended. ... All the prisoners were happy the experiment was over, but most of the guards were upset that the study was terminated prematurely." (Zimbardo,

In 2002, Phil Zimbardo became President of APA.

In 2002, the BBC did a reality-TV program, The Experiment, loosely repeating this prison study. (So, again, the journalists can do something that academics can't?)


This project seems to have all the precautions (e.g., police consultants, former prisoner consultants, etc.), admirable objectives (improving treatments in prisons), and healthy volunteers. No doubt this was helped along by the big-name location and personnel (can you imagine it being allowed for Asst. Prof. Joe Blow at Western North Dakota State University?). And it was reviewed by the Stanford Human Subjects Research Panel (was there a big grant involved that the University wanted to keep?). Nonetheless, 50 visitors to the site while the project was underway, including a priest and parents, let it continue, so it is hard to fault the review board.

I think the extremity of the outcome is what bothers us, not so much the methodology per se. But I have to wonder why this experimental result, in and of itself, would surprise anyone who has ever read "Lord of the Flies." (Or is that now a book banned by the "bias and sensitivity" police?) Further any participant or survivor of a fraternity hazing would be unsurprised as well, and likewise for various other "rites of passage" routines (e.g., boot camp and drill sergeants, military exercises, sports initiations, etc.).

The pattern of "cruelty" here was again already well-established in the real-life prison setting, so the main novelty of the research is that "nice people wouldn't do this." One can always wonder just how far this generalizes, but there is plenty of other evidence to suggest that many of us could respond this way. And these subjects were carefully selected for "normalcy," so a generalization to "the world" would have to include those who might have been sadists to begin with.

What was the "debriefing," and how effective was it, that is, the delayed impact (e.g., a week or month later)? Individual anecdotes are not not very helpful on this point. Was "support" offerred on a continuing basis after the experiment? The least one might expect in cases like this is extended follow-up.

Other than the extremity of the results, it is hard to be anything but disappointed and disgusted by the way this was allowed to go on for so long. Further, the positive spin that is placed on it by Zimbardo is worrisome, those post-hoc rationalizations are embarrassing. In spite of the pride that it didn't run for the full two weeks initially planned, six days was too long, by three days if not four. Would a lesser ego have realized this sooner? Would an independent experimenter? Whatever one thinks about the methodology or the question in general, I think the main problem here is the poor judgment of the experimenter after the project started, and the experimenter was far too involved in "helping things along." However, sad to say, I don't see how an ethics review board could foresee that, then or now.

"I was sitting there all alone, waiting anxiously for the intruders to break in, when who should happen along but a colleague and former Yale graduate student roommate, Gordon Bower. Gordon had heard we were doing an experiment, and he came to see what was going on. I briefly described what we were up to, and Gordon asked me a very simple question: "Say, what's the independent variable in this study?"

To my surprise, I got really angry at him. Here I had a prison break on my hands. The security of my men and the stability of my prison was at stake, and now, I had to deal with this bleeding-heart, liberal, academic, effete dingdong who was concerned about the independent variable! It wasn't until much later that I realized how far into my prison role I was at that point -- that I was thinking like a prison superintendent rather than a research psychologist."

The acid tests:

  1. Would it have been rejected by modern review boards? Almost certainly.
  2. Would the complications we've added to reviews since 1971 have prevented this? Lawyers? Lay people? Cultural diversity? Campus-level review? I don't think those would directly prevent it, but I do think that 30 years later it would be seriously questioned if not out-right rejected for general cultural change reasons. To support the probable ineffectiveness of the modern complications, that 50 visitors (including a priest) did not question it even when it was going on suggests to me that such changes per se wouldn't account for a modern rejection.
Maybe there is a lesson to be learned here though:
The IRB preoccupation with ink color, check boxes, and such seems just a variant of what Zimbardo's prison guards did to establish authority. -- make the prisoners (researchers) do petty and trivial stuff to establish the pecking order?