Stanford Prison Experiment- Part III. Conclusion


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The recent findings regarding the validity of the Stanford Prison Experiment have been disappointing. Even on a personal level. While the study was morally questionable it was one of my favorite studies. In college, I majored in psychology.  I found myself particularly drawn to social psychology. Naturally, my social psychology textbook dedicated several pages to the Stanford Prison Experiment. Despite the litany of ethical questions and procedural constraints that have spawned from SPE and the infamous Milgram’s Experiment, the controversial studies have always been the most intriguing to me.


When I was younger often flippantly reducing the ethical considerations to mere inconveniences. As I have gotten older, I have begun to take the ethics of research more seriously. Veering away from a sterile utilitarian mentality to one that holds the rights of the subjects in high esteem. Needless to say, I had to reluctantly acquiesce the fact that one of the most interesting studies conducted in the history of psychological research was a fraud.  In science when new fact-based developments come to surface we must except them tentatively until proven otherwise. Even when the facts do not comport with our interests or opinions.


Even though it is reasonable to suspect that the Stanford Prison Experiment was fabricated, are any of the results salvable? The results certainly are not scientifically valid nor can be generalized. That is a difficult question to answer. An exact replication of this study is out of the question.  As the purveyor of the Prior Probability blog has mentioned in the comments section of part II, ethical constraints prohibit an exact replication. However, in the United Kingdom, an amended version of the study was conducted back in 2001. Typically referred to as the “BBC Prison Experiment“. This more ethically amenable study did not fully verify the results of Zimbardo’s 1971 study. In 2018, Zimbardo came back and criticized the UK experiment and cited a 1979 study that mirrored his results. Such back-peddling can only be met with incredulity considering the ample evidence that Zimbardo heavily manipulated the results of his 1971 “experiment”.


Philip Zimbardo’s desired results do dovetail to our initiative assumptions about authority. We have all heard the expression of being “drunk on power”. It was the great Lord Acton that once said:

Power tends to corrupt and absolute power corrupts absolutely. Great men are almost always bad men, even when they exercise influence and not authority…


It is quite evident that an implied potential for abusing authority is embedded in the human psyche. The problem becomes determining whether this qualitative attribution is factual or illusory. To do so through scientific means is downright cumbersome. Attempts to quantify an inherently qualitative value judgment is difficult. However, there seems to be quite a bit of anecdotally/observational evidence that does point in the direction of Zimbardo’s findings.  The unfortunate aspect of observations is that we cannot deduce the prime cause of the observed occurrence. It is possible that the root cause could be an unobservable variable or our observation is clouded by bias.


The instances of torture at the Abu Ghraib prison would appear to be observational evidence congenial to Zimbardo’s results. Per a 2012 paper written by Kristin Richardson, the situational context of the Abu Ghraib prison may explain the behavior of the guards. Suggesting that the fact that senior leadership was complicit in the controversy for fostering an environment where such human rights violations can take place (p.76-77).  This lack of oversight being prevalent in other areas of interacting with prisoners of war such as interrogation.  Richardson also cites what is known as the Thomas Theorem for addressing how the soldiers guarding the detainees at Abu Ghraib could resort to inhumane measures. This theorem asserts that reality is a mental construct and that reality is real because we believe it is (p.9). Leading to the assumption that the guards did lose a sense of consensus reality while in prison. Started to relax their moral precepts to accept the role of an uncompromisingly tough prison guard. Keeping potential terrorists in-check. Providing some qualitative confirmation about Zimbardo’s assumptions regarding the behavior of the guards in the Stanford Prison Experiment.


Having an understanding of the human mind, I understand how powerful it is. It has the capability of making a delusion a reality. Reinforcing the observations asserted in Plato’s Allegory of the Cave thousands of years before the advent of neuroscience.  People can get caught up in a fabricated reality. To not only believe they can get away with abusing prisoners but to believe they are justified. This distortion of reality being triggered by the context of the environment. That does not mean that reality is a complete construct. The fact that there is a consensus reality is a clue that not every aspect of experience is subjective. We merely interpret concrete reality through sensory input creating the spectrum of deviations. As intriguing as Richardson’s insights are they still do not provide us with any causal inferences. Due to ethical and methodological concerns, we may never be able to validate these observations scientifically.






Stanford Prison Experiment- A Fraud? Part II

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The Stanford Prison Experiment is arguably one of the most famous studies in the discipline of social psychology. Mentioning the study by name generally evokes images of the darker side of the human condition. As you can see from my previous essay detailing the reported qualitative details of the study.  Dr. Zimbardo’s controversial study garnered much attention to the ethical considerations of psychological research. While the study has been widely cited and profoundly influential in recent years it has come under fire. Back in 2018, journalist Ben Blum, published an expose scrutinizing the validity of Zimbardo’s work. Exposing major methodological flaws that most likely compromised the results. Even inferring that Zimbardo attempted to manipulate variables to influence the results.


Could one of psychology’s most well known and influential studies be completely invalid? Contrived and orchestrated like a school play? Such a determination veers into murky waters.  It can be said confidentially that Zimbarado’s methods were flawed  From the standpoint of methodology, the ethical considerations are a whole other subject. When applying the scientific method to research it is imperative to control for any confounding variables. This is the only way to confirm that the results are being impacted by the variables being manipulated by the experimenter. Otherwise, the results fall victim to the third variable problem. Making it impossible to derive causation from the results of the study. At the very least Zimbardo was derelict in regards to preventing outside factors from contaminating the results.


From a methodologically the Stanford Prison Experiment suffers from poor data collect, faulty participant selection,  and the demand characteristics of the study.


Poor Data Collection:  


Anyone who has read Zimbardo’s 1971 paper can tell you two characteristics are striking. The first being the unorthodox composition of the paper. The second being the paucity of hard data. The details of the paper are almost entirely qualitative. Making the term experiment an unfitting title for the study. French researcher Thibault Le Texier would most likely agree. In his paper, Debunking The Stanford Prison Experiment, he highlights many of the methodological flaws in the study. His research reveals that only 15% of the total “experiment” was recorded. “6 hr of video and 15 hr
of audio” out of the total 150 hours devoted to the experiment. No data was collected during day three of the study (p.12). Such gaps in data collection can only put the results of the study in question. Without sufficient data, the researchers are merely speculating. Presenting speculation as scientific findings are intellectually dishonest and problematic.


A touchstone of scientific inquiry is the ability to control for confounding variables. Extraneous variables that influence attributes being studied and swaying the results. How do we know that the results of Zimbardo’s study were truly due to the situational conditions of being granted unfettered authority over other people? Unfortunately, we cannot. Per Le Texier’s archival research   Zimbardo “collected very little personal information about the participants”(p.12). This is profoundly problematic if we are expected to draw causal results from this study. Zimbardo neglecting to collect adequate background information on the subjects generates more questions than answers. The cruel behavior of the guards may have been influenced by factors other than the situation. For example personality traits, political beliefs, religious convictions, etc. Not collecting such preliminary data not only skews the results but is just plain sloppy. Any experienced researcher should have known better to be so cavalier.


It has also come to surface that Zimbardo did not collect any data from actual prisons. Again, another fault in data collection that prevents these findings from being generalized. Without data from prisons, it is difficult to not only have an accurate understanding of typical behavior in these environments, but nothing to compare the results. Yes, you could utilize behavior before the experimental conditions as a baseline. However, this does little if you are seeking to make universal claims about the behavioral dynamics of prisons. In the absence of this information how can really can’t. The results could be atypical for the average prison.


Participant Self-selection:


The experiment suffered from one fatal error from the very beginning that could have impacted the results. Zimbardo placed an advertisement in the local paper requesting volunteers for a prison experiment (p.2). Even providing the detail of the study is a “prison” experiment in the process of soliciting participants allows extraneous variables to creep in. Contaminating the results. Individuals who may be interested in a prison study may skew towards people with a specific personality type, ideological convictions, or other proclivities. Thereby generating an applicant pool that may be predisposed towards authoritarian tendencies.  As unlikely as this sounds considering we are talking about a group of college kids in the 1970’s California, it cannot be ruled out. It cannot be ruled out because Zimbardo failed to shield the study from self-selection. This concern would even be a talking point if Zimbardo had merely request for participants for a study versus a “prison study”.


Speaking of an experiment taking place in a prestigious university in the 1970’s California, that is a really specific and unique time and place. Bringing to light another question, the generalization of participants. Generally, when you select subjects for a study, you want the pool of applicants to be as diverse as possible. Why? More diversity greatly reduces the likelihood of sampling error. The general population of the United States is extremely diverse. To reflect this, you need a diverse pool of participants to randomly select from. Otherwise, you run the risk of potentially selecting subjects that maybe all have similar characteristics that do not reflect the overall population. The greater the number and diversity of subjects any peculiarities tend to washout, averaging results that can be generalized. Would a bunch of college students presumably attending Stanford be a good representation of the American population? By any metric or measure that would be a resounding no!


Demand Characteristics:


Demand Characteristics in an experiment are “ques” that subconsciously influence the behavior of the subjects. For example, knowing the experimenter’s expectations or desired results impacting participant behavior. Once again, Zimbardo was derelict in his duty as a researcher to avoid such issues. Zimbardo expressed what his expected and desired outcomes were for the experiment to the guards during orientation (p.5). The guards also expressed feeling as if they were being “watched and filmed” (p.8). It is quite evident that when feel as if we are being observed we are more apt to behave differently. Especially when the lead experimenter has already expressed his opinions about the potential results. This fact is solidified in the testimony of Guard #1:


He wrote to Zimbardo, 3 months after the experiment, “I was always acting [. .] I
was always very conscious of the responsibility involved in the guards’ and the experimenters’ positions; I mentioned this to various people at various times, including to you during the debriefing” (Guard 1, 1971b). He wrote to him again, 3 months later,
I consciously felt that for the experiment to be at all useful ‘guards’ had to act something like guards.

[. . .] I felt that the experiment was important and my being ‘guard-like’ was part of finding out how people react to real oppression. (Guard 1,1972, p. 5)

(Le Texier, 2019, p. 8)



Unfortunately, it is speculated that to a certain extent the study was scripted and fabricated. Extends beyond the concerns of demand characteristics. Le Texier found that Zimbardo had prewritten conclusions for the study (p.13). There is ample evidence that the experimenters had conditioned the prisoners and guards in how to behave (p.10). Explaining to the participants how to behave in the context of the experiment. Zimbardo and the other researchers claim that the cruel behavior of the guards to have occurred organically is beyond spurious. Especially when the subjects were being coached.  To make matters worse, the experiments even played an active role in the experiment. Removing themselves from the role of impartial observers. The role of warden was played by one of Zimbardo’s experimenters.












The Stanford Prison Experiment- An Introduction. Part I

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What was the Stanford Prison Experiment: 


The Stanford Prison Experiment was a study conducted on August 14th through 20th of 1971 by Philip Zimbardo, Craig Haney, W. Curtis Banks, and David Jaffe. The lead researcher Zimbardo embarked upon this study to examine how situational factors and authority could lead to normal people engaging in abhorrent behavior. The researchers placed an advertisement in the local paper looking for volunteers for the experiment. The researchers performed psychological evaluations to make sure that the participants were healthy and not suffering from previous mental conditions. Then they were arrested by actual Palo Alto police officers. Underwent standard  booking procedures and were taken to a basement on the Stanford campus. Out of the eighteen participants nine were assigned to be guards and the other nine were prisoners. The roles were randomly assigned by a coin toss.


The guards stripped the prisoners naked and sprayed them down with delousing spray. The prisoners were then dressed in jumpsuits  (without undergarments) and provided nylon stockings to wear on their heads to mimic the practice of head-shaving in prisons.  Each prisoner was assigned a number and was only referred to by their number. The guards periodically took counts on the faux-inmates. The inmates went to the bathroom in buckets and were escorted by the guards to the makeshift facilities. Generally with a bag over their heads. The subjects that were assigned to the role of guards purportedly developed their own rules for governing the mock prison. These “guard” devised parameters included punishments such as limitations on food, solitary confinement, and push-ups. As time went on the severity of guard sanction punishments increased drastically. Even include instances of sexual humiliation ranging from forcing the prisoners to remove their clothes to even  forcing them to simulate sodomy. Such displays of cruelty were lead by the sadistic ring-leader David Eshelman, referred to by the prisoners as “John Wayne”.


Due to the concern about the well being of the subjects Zimbardo cut the experiment short. It was originally planned to run for two weeks and was ended after six days. By day five one of the prisoners had developed a rash that was assumed to be psychosomatic. Engendered by the psychological distress (p.14) Instanced of prisoners who refused to eat being force feed by guards. Then there was the story of prisoner 819.


The only prisoner who did not want to speak to the priest was prisoner
#819 who was feeling sick and had refused to eat…While talking to us he broke down and began to cry hysterically, ..While I was doing this one of the guards lined up all of the prisoners and had them chant aloud.

As soon as I realized that #819 was hearing all this, I raced into the room where I had left him, and what I found(66)was a boy crying hysterically while in the background his fellow prisoners were yelling and chanting that he was a bad prisoner…

“OK, let’s leave.” Through his tears, he said to me, “No, I can’t leave.” He could not leave because the others had labeled him a bad prisoner. Even though he was feeling sick, he was willing to go back into that prison to prove that he was not a bad
prisoner. (Zimbardo, Haney, Banks & Jaffe. 1971. P. 12.)