Stanford prison experiment

Date: 1970s

Type of psychology: Social psychology

Designed and led by renowned psychologist Philip Zimbardo, the Stanford prison experiment is a case study that illustrates the overriding power of the situation to transform good people into authoritarians and sadists. The study illuminates the dark side of human nature, which can emerge under the right set of circumstances.

Introduction

In 1971, a prison was constructed in the basement of Stanford University’s psychology building. The makeshift prison was to provide a realistic setting for examining the effects of simulated confinement on prisoners and guards. The Stanford prison experiment, designed and led by Philip Zimbardo, a renowned psychologist and professor emeritus at Stanford University, is a case study that demonstrates how the power of a situation can transform those who are generally regarded as good people into authoritarians and sadists. It highlighted the ability of human nature’s dark side to emerge under certain circumstances.

Truly a classic study in psychology, the Stanford prison experiment is one of the best known and most widely cited experiments in the field, as well as one of the most controversial. The investigation has been discussed in most introductory psychology courses since the early 1970s. Videos or still photos of the experiment have been featured in television documentaries and news magazines, are shown to students in undergraduate classes, and appear on the Internet. The study, along with Stanley Milgram’s obedience to authority experiment, has become widely known outside the realm of psychology.

Prison Simulation

To bring realism to the experiment, the study began with televised, dramatized arrests of the student participants by the Palo Alto Police Department. Arrests were followed by a real-life booking process: handcuffing, fingerprinting, and photographing (mug shots), as well as the conducting of strip searches and the assignment of numbers to the detainees, which gave the students a new identity. The study even involved fictitious parole board hearings, administered by an actual former prison inmate, in which students pleaded for their release. The experiment ended abruptly and unexpectedly after six days instead of the scheduled fourteen because of the emotional suffering of the prisoners and the escalating abusiveness of the guards, which took the form of sleep deprivation, sexual humiliation, physical abuse, solitary confinement, incessant prisoner counts, and mindless activities. Half of the student prisoners had to be released from the study because of psychological strain.

Participants

Before being selected for the study, participants were thoroughly assessed for mental illness, medical disabilities, and personality or character problems. The participants were twenty-four healthy undergraduates with no hint of severe emotional problems or predilections toward violence or any other maladaptive behaviors. Not only were the experiment guards and prisoners free of significant emotional problems as they began the experience, they were also randomly assigned, by a coin toss, to their respective roles for a two-week study of authority and social influence. Yet, the behaviors of the inmates and guards in the ersatz prison belied their scores on the personality tests.

Transformations

The students became guards and inmates through a simple change of uniform. The prison-based conversion was facilitated by two complementary processes: deindividualization and dehumanization. Deindividualization allowed the guards to hide behind uniforms, badges, ranks, and titles. The detention officers in the experiment donned mirrored sunglasses, wore khaki uniforms, carried batons and whistles, and insisted on being addressed as “Mr. Corrections Officer,” all of which fueled the sadistic behaviors they directed toward the inmates.

When the student-guards entered the basement of Stanford University’s psychology building, they not only put on a new set of clothes but also assumed the mantle of authority. In the experiment, the inmates wore flimsy gowns, which were undignified and demeaning. They were forced to cover their hair with nylon stocking caps, which further eroded their identities. Inmates were stamped with insulting names as part of a ritualized depersonalization and demoralization process. They were punished by the guards’ ordering them to sleep on the floor; having them perform exhausting exercises and mindless, repetitive activities; restricting their use of the bathroom facilities; locking them in a solitary confinement closet; and forcing them to engage in simulated homoerotic behaviors. The research participant-inmates were no longer individual students, but a collective caricature of prison dwellers.

The student-inmates became abjectly submissive young men whose dialogues and interactions were scripted by the surroundings that dictated their behaviors, self-perceptions, and even their thoughts about others in the situation. The roles ossified as the research unfolded and eventually unraveled. The experiment showed that even a brief period of confinement in a contrived prison environment can precipitate short-term mental health problems in a sample of seemingly healthy young men.

In the experiment, Zimbardo maintained enough distance from the guards and gave them loose rules of engagement with prisoners (keep order, permit no one to escape, and commit no acts of violence) so that they enumerated their own set of regulations, which were applied arbitrarily and often with the sole intention of controlling and tormenting the inmates. In addition, the tacit approval of the abuse by the warden and prison superintendent (Zimbardo) most certainly encouraged more abuse. In submerging himself in the role of prison superintendent/principal investigator, Zimbardo lost his perspective and reasonable judgment. He wore dark glasses while running the prison, and he was blind to the escalating abuse even though he reviewed the audio and videotapes that recorded each day of confinement.

The bystander effect operated in the experiment as the “good” guards permitted the most sadistic ones to define appropriate actions. Not wanting to be chastened by fellow guards, the more humanitarian ones did nothing while the dominant ones meted out their punishments and degradations. The guards who were exceptionally physically imposing and harsh, particularly during the night shift, created a natural hierarchy of leaders and followers, setting the stage and atmosphere for the guards to imitate and revel in the sadistic treatment of inmates.

The guards at Stanford University prison probably feared losing face in front of their compatriots, being superseded by a superior officer or alpha guard, or offering unwanted assistance. As the situation was highly ambiguous, the guards monitored and mimicked the reactions of others in the prison; their motivation was to ascertain and follow acceptable standards of behavior. As no one lodged complaints about inmate mistreatment at the prison facility, the abuse continued and escalated. The inaction of others, especially the leadership, led the “good” guards to conclude that the situation must be acceptable, which is an example of pluralistic ignorance and social proof.

Conditions in the Stanford University prison acutely deteriorated following an escape attempt and an uprising of the prisoners in protest of their shoddy treatment and harsh conditions. The uprising was followed by more mistreatment and violence against the inmates. The prison guards and leadership took precautions to thwart future outbreaks of dissension, which they believed demanded stricter rules and a further crackdown on inmates’ rights and privileges, thus beginning the slippery slide down the slope of abuse and mistreatment. Echoing the times, some of the inmates organized a group to present their demands and rally for justice; one went on a hunger strike. These activities were to no real avail and served mostly to justify the progressively harsher treatment issued by the guards.

Termination of the Study

At Stanford University prison, Christina Maslach, a graduate student in psychology at Stanford University, was helping Zimbardo conduct interviews with the student prisoners. After listening to her complaints about the cruelty of the study, he terminated the research and debriefed the participants to educate them about the experience and to forestall future mental health problems.

Later Studies

Decades after the original study, in 2007, Thomas Carnahan and Sam McFarland tested to see if the researchers investigated whether students who selectively volunteer for a study of prison life might possess characteristics that predispose them to act abusively. To recruit subjects for the study, the investigators posted a newspaper advertisement that was virtually identical to the one used in the Stanford prison experiment. One advertisement included the term “prison life” while the other did not. Those who volunteered for the “prison study” scored significantly higher on measures of aggressiveness and authoritarianism, which are directly related to the propensity toward aggressive abuse, and lower on empathy and altruism, which are inversely related to the propensity toward aggressive abuse. These results challenge the conclusions of the Stanford prison experiment, which suggested that behavior is determined entirely by the situation rather the person in the situation or the interaction between the person and the situation.

Bibliography

Banuazizi, Ali, and Siamak Movahedi. “Interpersonal Dynamics in a Simulated Prison: A Methodological Analysis.” American Psychologist 30.10 (1975): 152–60. Print.

Carnahan, Thomas, and Sam McFarland. “Revisiting the Stanford Prison Experience: Could Participant Self-Selection Have Led to Cruelty?” Personality and Social Psychology Bulletin 33.5 (2007): 603–14. Print.

Cherry, Kendra. "The Stanford Prison Experiment ." VeryWell Mind, 16 Apr. 2021, www.verywellmind.com/the-stanford-prison-experiment-2794995. Accessed 10 Feb. 2023.

Drury, Scott, et al. “Philip G. Zimbardo on His Career and the Stanford Prison Experiment’s Fortieth Anniversary.” History of Psychology 15.2 (2012): 161–70.

Haney, C., W. C. Banks, and Philip G. Zimbardo. “Interpersonal Dynamics in a Simulated Prison.” International Journal of Criminology and Penology 1.1 (1973): 69–97. Print.

Haney, C., W. C. Banks, and Philip G. Zimbardo. “Study of Prisoner and Guards in a Simulated Prison.” Naval Research Reviews 9.2 (1973): 1–17. Print.

Haslam, S. Alexander, and Stephen. D. Reicher. “Contesting the ‘Nature’ of Conformity: What Milgram and Zimbardo’s Studies Really Show.” PLoS Biology 10.11 (2012): 1–4. Academic Search Alumni Edition. Web. 1 July 2014.

Haslam, S. Alexander, and Stephen D. Reicher. “When Prisoners Take Over the Prison: A Social Psychology of Resistance.” Personality and Social Psychology Review 16.2 (2012): 154–79. Academic Search Alumni Edition. Web. 1 July 2014.

Konnikova, Maria. “The Real Lessons of the Stanford Prison Experiment.” New Yorker. Condé Nast, 12 June 2015. Web. 29 Feb. 2016.

Zimbardo, Philip G. The Lucifer Effect: Understating How Good People Turn Evil. New York: Random, 2007. Print.