Was the Stanford Prison Experiment a sham? A Q&A with the writer who exposed the celebrated study

Journalist Ben Blum cites new evidence that points to choreographed results and pre-ordained conclusions

Conducted during the summer of 1971, the Stanford Prison Experiment was often criticized for its methods, but ultimately lauded for its conclusions about human nature. Courtesy of the Stanford Historical Photograph Collection.

You don't need a psychology degree to have heard about the Stanford Prison Experiment.

The famed research-endeavor-turned-nightmare earned ample publicity after it concluded in August 1971. By design, Stanford psychology professor Philip Zimbardo left 24 college-age males locked in the university's basement for six days, posing as prisoners and guards. In evoking apparent emotional trauma, he claimed to have demonstrated a new psychological truth: That evil-doing stems from situation and authority, not one's morality or personal characteristics.

That principle has been an immovable fixture of psychology textbooks and legal defenses— not to mention the pop culture canon — ever since.

Turns out it could be wrong.

In his sharply reported article, "The Lifespan of a Lie," Ben Blum lays out why the Stanford Prison Experiment and its supposed conclusion could be bogus.

In reporting based on recent interviews and newly-released documents, Blum explains that Zimbardo and his assistants essentially choreographed much of the behavior, therefore "fostering exactly the pathological behavior that Zimbardo would later claim had arisen organically." In an interview with Blum, one of the inmate participants revealed that his much-cited breakdown was merely acting on his part. Another revealed that Zimbardo had encouraged the guards to act aggressively.

According to Blum, Zimbardo knowingly hid these aspects of the experiment for years, maintaining tight control over the narrative, and ultimately allowing the project to become thoroughly and incorrectly enmeshed with our perception of human nature.

We talked to Blum about what he found, why it matters and what we should think about the experiment going forward.

What motivated you to start looking into this?

I'd always been aware of the Stanford Prison Experiment in the kind of vague way that I think a lot of people are aware of it. But my first personal contact with Zimbardo came as he became involved in the legal defense of my cousin, Alex Blum, who participated in an armed bank robbery carried out by a team of army rangers in 2006. He was a 19-year-old teenager at the time, and he explained to my family that he thought the whole thing was a training exercise carried out by his superiors. [Blum wrote about the experience in his 2016 book, Ranger Games.

I read Zimbardo's book The Lucifer Effect then. I found it immensely helpful with trying to understand someone who I knew to be of good character — an idealistic, patriotic guy who always wanted to be an army ranger and then was involved in behavior beyond the pale of what our family considered him capable of. I was completely onboard with Zimbardo's research.

And then things started to get a little weird. Alex confessed to me that he had known more about the crime then he had let on before. It was indeed pitched to him as a training exercise, but by the time the bank robbery happened, he knew that it was the real deal. He lacked the courage to back out.

That was the moment my kernel of doubt appeared. I wondered how much explanatory power the Stanford Prison Experiment really had. It began to seem simplistic to give situational factors so much primacy in explaining why we do what we do, in explaining evil actions.

I stared reading a little more. The big turning point came when I watched the feature film in 2015 and noticed a few key departures from the factual event as I understood it.

To be clear, that film was a fictionalized telling, right?

It was — that's important to note. For me, it raised some interesting questions about what extent departures from a historical record are justifiable in a retelling of a scientific experiment versus a historical drama or biopic. There seems to be a different standard of truth than the standard that we apply to history.

I was curious to what narrative end these factual departures served. So I went back to Zimbardo's book and began mapping it out. I was shocked to discover a whole other story of the experiment lying just under the surface of the rhetorical devices that Zimbardo has been using for a long time to obscure it.

And then I gradually began reaching out to former subjects, finding that their accounts supported this alternate narrative. Many of them were quite upset with the use that Zimbardo had made of their story. They felt their experiences had been misrepresented over the years.

It all kind of snowballed from there for me.

Your article references the work of Thibault Le Texier. (A french filmmaker and academic, Le Texier's Histoire d'un Mensonge, "History of a Lie," was published this April. It includes newly released archival material with revealing details about the experiment.) How did his work inform yours?

Le Texier deserves a ton of credit. But I'd actually reached my conclusion independently of him. I was first starting to pitch a piece about this about a year ago, and as I started interviewing more and more people, I started hearing, "Hey, I just spoke to this French guy." He and I have been in communication ever since.

The final moment that really clicked it in for me was when I talked to Zimbardo. I was able to interview him about Le Texier's findings, which Le Texier himself was not able to do.

As Zimbardo changed his story over the course of the conversation, I realized these were more than just slips of the tongue.

I'm curious why the prisoners and participants didn't come forward sooner.

I think we're seeing these dynamics play out in a number of different arenas right now. Powerful figures are able to control a narrative for years because the people that have been adversely affected don't know each other and aren't able to synthesize their experiences in order to change the narrative. There were a lot of individual voices out there, but they weren't uniting.

There also wasn't yet a strong alternative scientific explanation for the truly awful things that happened in the Stanford Prison Experiment. I think new research by Alex Haslam and Stephen Reicher (who performed a similar experiment in Great Britain in 2001) is very important in this regard, giving us a scientific way forward.

The experiment has been used to give us some comprehension of tragically cruel phenomena — everything from the Holocaust to ISIS. Do we know less about the psychological factors at play than we thought?

I do think we need to rethink our understanding of almost everything the experiment has been used to explain.

The findings offered a very simplistic view of the nature of human wrongdoing. The experiment implied that evil is lurking in all of us, just waiting for us to put on the right clothes and be given power to express itself — waiting for a situation. And 'situation' is defined in this very limited psychological way as the kind of thing you can create in a lab from scratch.

I think the implications of Haslam's and Reicher's research do a better job of accounting for some of the things that the Stanford Prison Experiment used to be offered to explain. The basic theory is that we are more prone to follow orders when we identify with the leader who seems to share our values and frames those orders in the language of our shared values.

Do you blame Zimbardo for our false understanding?

I think certainly there was a hunger in the culture for the story Zimbardo was telling, but, yeah, Zimbardo is a master storyteller. He's devoted an enormous amount of resources over the years to promoting this narrative.

There was the documentary, Quiet Rage, in the mid-80s. There was the PBS documentary series, Discovering Psychology. There was the book, The Lucifer Effect. He spent something like 20 years trying to get a feature film made about it.

And he's also been involved in several legal cases over the years, invariably defending someone who's done terrible things within an institutional setting. The most prominent of those being Ivan "Chip" Frederick, the non-commissioned officer in charge of the guys who committed the Abu Ghraib abuses.

You mention the public sort of hungered for this story — what was it about the takeaways from the experiment that we so wanted to believe?

I think the most seductive feature of the Stanford Prison Experiment is its ability to diffuse away all moral accountability.

The people who commit abuses aren't accountable because they were just slipping into a role. The people who are giving the orders aren't accountable because they too were just slipping into a role. And then the people who are being abused have no agency to better their situations because they are equally a victim of circumstance.

And that message is very convenient. If you feel powerless in the face of institutional forces larger than yourself — as everyone does at one time or another — there's a personally seductive explanation and politically seductive explanation.

Also, it's just a cracking good tale. A mock prison was built in the basement of the Stanford psychology department. I mean, how crazy is that? What we've realized now is that these prisoners were really led to believe that they couldn't escape this nightmare experiment that they were trapped in. It was even worse than the story made it out to be for so many years.

What kind of reaction have you gotten from the public?

I've been a little overwhelmed by the response. Quite a lot of psychology professors and sociology professors have been discussing the article on twitter, calling for the experiment to be removed from textbooks. There's discussion about the new research by Haslam and Riecher.

It's been very encouraging. I had my doubts that anything could topple this narrative at this point.

Is your article a cautionary tale about our willingness to accept scientific research?

Psychology is in the midst of a replication crisis, and I think these new revelations about the Stanford Prison Experiment can't help but lend to the argument that we need to be more careful. We need to be more scrupulous in trumpeting the data from psychological experiments.

But I really do not want this to be seen as some kind of referendum on the field of psychology. I think we're learning important new things about human nature, and I don't think the Stanford Prison Experiment was conducted in fully bad faith. I think Zimbardo was genuinely interested in how institutional forces shape human behavior.

And there still is really interesting stuff in that data. Part of what's so exciting about the narrative cracking open is that it's giving us a fresh look at what really happened in an experimental setting that can't ever be repeated for ethical reasons.

So people should not lose faith in science. Forces can prevent us from being as questioning as we should about canonical experiments. But the progress toward truth keeps marching along.

This interview has been edited for length and clarity.

In response to Blum's piece, Zimbardo published a 26-page defense of the experiment. Among his detailed criticisms of Blum's article, Zimbardo alleges:

• There's evidence to show the prisoners and guards weren't faking it.

• The British experiment by Alex Haslam and Stephen Reicher is not scientifically valid.

• He worked to make archival material public over the years and kept nothing hidden.

• The underlying takeaway of the SPE is not that perpetrators should be absolved of their sins, but that "preventing undesirable behavior of individuals or groups requires an understanding of what strengths, virtues, and vulnerabilities that they bring into any given situation.

• Read Zimbardo's 26-page response written to recent criticisms of the Stanford Prison Experiment here. is a sister publication of Palo Alto Online, covering what to eat, see and do in Silicon Valley.


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9 people like this
Posted by AJL
a resident of Another Palo Alto neighborhood
on Jul 1, 2018 at 9:50 am

Huh. Interesting. I think there is definitely an aspect of human nature that wants to believe anything with an urban legend ring to it, that's what makes urban legends. I wonder if anyone has studied what makes a good urban legend or can share that, and how it may be relevant here?

My favorite example of that in medicine would be the placebo effect. Some researchers in Germany in the '90s took a much more methodical look at the evidence and found that placebo effect research was characterized mostly by "sloppy methodological thinking" -- people wanted to believe what they wanted to believe about it.

So, ironically, people's beliefs about the placebo effect were more at issue than what happened physiologically because of people’s beliefs in treatment, which turns to be mostly a myth. A Danish group did a really thorough study in which they identified the published studies with good enough data since the introduction of the placebo effect, in which there were three groups: a group that got treatment, a group that got a placebo intended to mimic treatment, and a group that got nothing. They compared the placebo groups to the groups that got nothing (no treatment, no expectations of treatment) and found that there is no significant clinical effect associated with placebos.

Placebo effect study designs often lump in anything that isn't a treatment effect -- such as researcher biases, patient reporting biases, normal course of a disease, independent effects of placebos (which aren't always just sugar pills), belief in treatment, etc -- but then the results in studies involving placebos are then often interpreted just as having resulted from belief in treatment. We now know the latter simply doesn’t cause significant physiological changes. The problem is that the belief in treatment interpretation captures that urban legend popular imagination and just won't die, even in many scientific circles, despite so much strong scientific evidence that it's not correct.

So, the placebo effect -- as defined as significant physiological effects resulting from belief in treatment (or belief in negative effects from treatment) -- is largely a myth. Isn't that ironic? It's not that placebo trials are unnecessary, because placebos are needed to separate the effects of treatment from all kinds of other effects and biases, but the idea that people can through belief in treatment make major physiological changes just isn't supported by the evidence. The Danish researchers did another major study of every trial involving three groups after their original research was published and found the same thing.

I cannot judge whether this book is correct or not based on just this article. But this is a very interesting claim about it and I am interested in learning more. I really wish I could look at all sides here with a better understanding of the urban legend phenomenon, too, and why some beliefs so stubbornly hang on in popular imagination despite almost incontrovertible evidence to the contrary.

6 people like this
Posted by Longtime Resident
a resident of Another Palo Alto neighborhood
on Jul 1, 2018 at 2:37 pm

Amazing how many news stories, facts and data, delivered to us with authority in its day, have been proven to be incorrect, today.

Most amazing is some people knew of the falsehoods, yet remained quiet, allowing the public to be bamboozled.

1 person likes this
Posted by Anon
a resident of Another Palo Alto neighborhood
on Jul 1, 2018 at 3:32 pm

Another way to view this is that there is currently a healthy trend towards more robust results and reproducibility.. One take on this can be found in the cartoon xkcd:

Web Link

Here is a serious article on the general subject in Nature:

Web Link

Regarding the famous Stanford Prison Experiment: "The past is a foreign country. They do things differently there." We now have IRBs and Human Subjects Committees and such. Don't expect to see the Zimbardo and Milgram experiments "reproduced".

Web Link

Instead, as suggested in the article, new research will bring better insight into how these aspects of human psychology work. And, I would like to hope, perhaps these new insights can help us build better political structures in the future.

2 people like this
Posted by CrescentParkAnon.
a resident of Crescent Park
on Jul 2, 2018 at 12:42 am

>> In reporting based on recent interviews and newly-released documents, Blum explains that Zimbardo and his assistants essentially choreographed much of the behavior, ...

I guess that means much like violence is choreographed with dead bodies, violence, war, terrorism, guns and retribution hundreds of time a night on TV and in the movies?

It just seems like there is data from these experiments, closed data to most of the public, that can be used to invet and develop some pretty nasty technology, as in Abu Graib or maybe wherever we have no heard about yet. Since we see that the majority of human behavior studies in the US seem to be applied towards manipulating people to buy something or do something maybe we should rethink the way we look and study human behavior and how that is put to use, more reliably then hooking people on drugs.

4 people like this
Posted by musical
a resident of Palo Verde
on Jul 2, 2018 at 1:29 am

Attend a City Council meeting.

2 people like this
Posted by CrescentParkAnon.
a resident of Crescent Park
on Jul 3, 2018 at 4:32 pm

> I think the most seductive feature of the Stanford Prison Experiment is
> its ability to diffuse away all moral accountability.

Ain't that the truth ... all the way to the top now. Seems like a lot more
research is needed on how to put in transparency and checks and
balances. At least our Founding Fathers were thinking in the right
direction. Some people are very clever at corruption and creating
disorder. Shouldn't anti-corruption and watching the watchers be
something important that we all should be thinking about? Seems
like these days governments are sitting ducks.

Like this comment
Posted by placebo effect
a resident of Old Palo Alto
on Jul 5, 2018 at 11:43 am

Interesting information above. I wonder whether the desire to believe in the placebo effect is similar to the desire to believe that there is a supernatural entity that watches over us and rewards believers.

Despite overwhelming evidence that innocent populations suffer, and over the centuries innocent people starve or are killed, die in floods, etc. some people still think there is a beneficent guardian who dispenses justice.

Believe, and the placebo effect will work? No it won't.

Sorry, but further commenting on this topic has been closed.

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