Stanford prison experiment

The Stanford prison experiment was a study of the psychological effects of becoming a prisoner or prison guard. The experiment was conducted in 1971 by a team of researchers led by Psychology Professor Philip Zimbardo at Stanford University. Twenty-four undergraduates were selected out of over 75 to play the roles of both guards and prisoners and live in a mock prison in the basement of the Stanford psychology building. Roles were assigned at random. They adapted to their roles well beyond that expected, leading the guards to display to authoritarian and even draconian measures. Two of the prisoners were upset enough by the process to quit the experiment early, and the entire experiment was abruptly stopped after only six days. The experimental process and the results remain controversial. The entire experiment was filmed, with excerpts soon made publicly available, leaving some disturbed by the resulting film. Over 30 years later, Zimbardo found renewed interest in the experiment when the Abu Ghraib torture and prisoner abuse scandal occurred.
Zimbardo and his team set out to test the idea that the inherent personality traits of prisoners and guards were summarily key to understanding abusive prison situations. Participants were recruited and told they would participate in a two-week prison simulation. Of the 75+ respondents, Zimbardo and his team selected the 21 males whom they deemed to be the most psychologically stable and healthy. These participants were predominantly white and middle-class.

The "prison" itself was in the basement of Stanford's Jordan Hall, which had been converted into a mock jail. An undergraduate research assistant was the "warden" and Zimbardo the "superintendent". Zimbardo set up a number of specific conditions on the participants which he hoped would promote disorientation, depersonalisation and deindividualisation.

The researchers provided weapons—wooden batons which could not be used to punish the prisoners, meant only to establish their status -- and clothing that simulated that of a prison guard—khaki shirt and pants from a local military surplus store. They were also given mirrored sunglasses to prevent eye contact.

Prisoners wore ill-fitting smocks and stocking caps, rendering them constantly uncomfortable. Guards called prisoners by their assigned numbers, sewn on their uniforms, instead of by name. A chain around their ankles reminded them of their roles as prisoners.

The researchers held an orientation session for guards the day before the experiment, during which they were told that they could not physically harm the prisoners. In The Stanford Prison Study video, quoted in Haslam & Reicher, 2003, Zimbardo is seen telling the guards, "You can create in the prisoners feelings of boredom, a sense of fear to some degree, you can create a notion of arbitrariness that their life is totally controlled by us, by the system, you, me, and they'll have no privacy... We're going to take away their individuality in various ways. In general what all this leads to is a sense of powerlessness. That is, in this situation we'll have all the power and they'll have none."

The participants chosen to play the part of prisoners were arrested at their homes and charged with armed robbery. The local Palo Alto police department assisted Zimbardo with the arrests and conducted full booking procedures on the prisoners, which included fingerprinting and taking mug shots. At the police station, they were transported to the mock prison where they were strip-searched and given their new identities.
The experiment quickly grew out of hand. Prisoners suffered — and accepted — sadistic and humiliating treatment from the guards. The high level of stress progressively led them from rebellion to inhibition. By the experiment's end, many showed severe emotional disturbances.

After a relatively uneventful first day, a riot broke out on the second day. The guards volunteered to work extra hours and worked together to break the prisoner revolt, attacking the prisoners with fire extinguishers without supervision from the research staff.

After only 36 hours, one prisoner began to act "crazy", Philip Zimbardo says; "#8612 then began to act crazy, to scream, to curse, to go into a rage that seemed out of control. It took quite a while before we became convinced that he was really suffering and that we had to release him."

A false rumor spread that #8612, who was now out of the experiment, would lead companions to free the rest of the prisoners. The guards dismantled the prison and moved the inmates to another secure location. When no breakout attempt occurred, the guards were angry about having to rebuild the prison, so they took it out on the prisoners.

Guards forced the prisoners to count off repeatedly as a way to learn their prison numbers, and to reinforce the idea that this was their new identity. Guards soon used these prisoner counts as another method to harass the prisoners, using physical punishment such as protracted exercise for errors in the prisoner count. Sanitary conditions declined rapidly, made worse by the guards refusing to allow some prisoners to urinate or defecate. As punishment, the guards would not let the prisoners empty the sanitation bucket. Mattresses were a valued item in the spartan prison, so the guards would punish prisoners by removing their mattresses, leaving them to sleep on concrete. Some prisoners were forced to go nude as a method of degradation, and some were subjected to sexual humiliation, including simulated sodomy.

Zimbardo cited his own absorption in the experiment he guided, and in which he actively participated as Prison Superintendent. On the fourth day, some prisoners were talking about trying to escape. Zimbardo and the guards attempted to move the prisoners to the more secure local police station, but officials there said they could no longer participate in Zimbardo's experiment.

Several guards became increasingly cruel as the experiment continued. Experimenters said that approximately one-third of the guards exhibited genuine sadistic tendencies. Most of the guards were upset when the experiment concluded early.

Zimbardo argued that the prisoner participants had internalized their roles, based on the fact that some had stated that they would accept parole even with the attached condition of forfeiting all of their experiment-participation pay. Yet, when their parole applications were all denied, none of the prisoner participants quit the experiment. Zimbardo argued they had no reason for continued participation in the experiment after having lost all monetary compensation, yet they did, because they had internalized the prisoner identity, they thought themselves prisoners, hence, they stayed.

Prisoner No. 416, a newly admitted stand-by prisoner, expressed concern over the treatment of the other prisoners. The guards responded with more abuse. When he refused to eat his sausages, saying he was on a hunger strike, guards confined him in a closet and called it solitary confinement.[2] The guards used this incident to turn the other prisoners against No. 416, saying the only way he would be released from solitary confinement was if they gave up their blankets and slept on their bare mattresses, which all but one refused to do.

Zimbardo concluded the experiment early when Christina Maslach, a graduate student he was then dating (and later married), objected to the appalling conditions of the prison after she was introduced to the experiment to conduct interviews. Zimbardo noted that of more than fifty outside persons who had seen the prison, Maslach was the only one who questioned its morality. After only six days of a planned two weeks' duration, the Stanford Prison experiment was shut down.
The Stanford experiment ended on August 20, 1971, only six days after it began instead of the fourteen it was supposed to have lasted. That day, Zimbardo called both the guards and inmates to a meeting and announced that the 'prison' was closing down. The experiment's result has been argued to demonstrate the impressionability and obedience of people when provided with a legitimizing ideology and social and institutional support. It is also used to illustrate cognitive dissonance theory and the power of authority.

The results of the experiment are said to support situational attribution of behavior rather than dispositional attribution. In other words, it seemed the situation caused the participants' behavior, rather than anything inherent in their individual personalities. In this way, it is compatible with the results of the also-famous Milgram experiment, in which ordinary people fulfilled orders to administer what appeared to be damaging electric shocks to a confederate of the experimenter.

Shortly after the study had been completed, there were bloody revolts at both the San Quentin and Attica prison facilities, and Zimbardo reported his findings on the experiment to the U.S. House Committee on the Judiciary
The guards and prisoners adapted to their roles further than expected, stepping beyond the boundaries of what had been predicted and leading to dangerous and psychologically damaging situations. One-third of the guards were judged to have exhibited "genuine sadistic tendencies", while many prisoners were emotionally traumatized (two of whom had to be removed from the experiment early). After being confronted by Christina Maslach, a graduate student in psychology whom he was dating,[4] and realizing that he had been passively allowing unethical acts to be performed under his direct supervision, Zimbardo concluded that both prisoners and guards had become too grossly absorbed in their roles and terminated the experiment after six days.[5] Ethical concerns surrounding the famous experiment often draw comparisons to the Milgram experiment, which was conducted in 1961 at Yale University by Stanley Milgram, Zimbardo's former college friend. Tom Peters and Robert H. Waterman Jr wrote in 1981 that the Milgram experiment and the Stanford prison experiment were frightening in their implications about the danger which lurks in the darker side of human nature.

The experiment was widely criticized as being unethical and unscientific. Current ethical standards of psychology would not permit such a study to be conducted today. The study would violate the Ethics Code of the American Psychological Association, the Canadian Code of Conduct for Research Involving Humans, and the Belmont Report. Critics including Erich Fromm challenged how readily the results of the experiment could be generalized. Fromm specifically writes about how the personality of an individual does in fact affect behavior when imprisoned (using historical examples from the Nazi concentration camps). This runs counter to the study's conclusion that the prison situation itself controls the individual's behavior. Fromm also argues that the amount of sadism in the "normal" subjects could not be determined with the methods employed to screen them.

Because it was a field experiment, it was impossible to keep traditional scientific controls. Dr. Zimbardo was not merely a neutral observer, but influenced the direction of the experiment as its "superintendent". Conclusions and observations drawn by the experimenters were largely subjective and anecdotal, and the experiment would be difficult for other researchers to reproduce.

Some of the experiment's critics argued that participants based their behavior on how they were expected to behave, or modelled it after stereotypes they already had about the behavior of prisoners and guards. In other words, the participants were merely engaging in role-playing. In response, Zimbardo claimed that even if there was role-playing initially, participants internalized these roles as the experiment continued.

More directly, though, it has been pointed out that, in contrast to Zimbardo's claim that participants were given no instructions about how to behave, his briefing of the guards gave them a clear sense that they should oppress the prisoners. In this sense the study was an exploration of the effects of tyrannical leadership. In line with this, certain guards, such as John Wayne, changed their behavior because of wanting to conform to the behavior that Zimbardo was trying to elicit.

Additionally, the study has been criticized on the basis of ecological validity. Many of the conditions imposed in the experiment were arbitrary and may not have correlated with actual prison conditions, including blindfolding incoming prisoners, not allowing them to wear underwear, not allowing them to look out of windows and not allowing them to use their names. Zimbardo argued that prison is a confusing and dehumanizing experience and that it was necessary to enact these procedures to put the prisoners in the proper frame of mind; however, it is difficult to know how similar the effects were to an actual prison, and the experiment's methods would be difficult to reproduce exactly so that others could test them.

Some said that the study was too deterministic: reports described significant differences in the cruelty of the guards, the worst of whom came to be nicknamed John Wayne. (This guard alleges he started the escalation of events between guards and prisoners after he began to emulate a character from the Paul Newman film Cool Hand Luke. He further intensified his actions because he was nicknamed John Wayne though he was trying to mimic actor Strother Martin who played the role of the sadistic Captain in the movie.[7]) Most of the other guards were kinder and often did favors for prisoners. Zimbardo made no attempt to explain or account for these differences.

Also, it has been argued that selection bias may have played a role in the results. Researchers from Western Kentucky University recruited students for a study using an advertisement similar to the one used in the Stanford Prison Experiment, with and without the words "prison life." It was found that students volunteering for a prison life study possessed dispositions toward abusive behavior.
When the Abu Ghraib military prisoner torture and abuse scandal was published in March 2004, many observers immediately were struck by its similarities to the Stanford Prison experiment — among them, Philip Zimbardo, who paid close attention to the details of the story. He was dismayed by official military and government efforts shifting the blame for the torture and abuses in the Abu Ghraib American military prison on to "a few bad apples" rather than acknowledging it as possibly systemic problems of a formally established military incarceration system.

Eventually, Zimbardo became involved with the defense team of lawyers representing Abu Ghraib prison guard Staff Sergeant Ivan "Chip" Frederick. He had full access to all investigation and background reports, testifying as an expert witness in SSG Frederick's court martial, which resulted in an eight-year prison sentence for Frederick in October 2004.

Zimbardo drew on the knowledge he gained from participating in the Frederick case to write The Lucifer Effect: Understanding How Good People Turn Evil (Random House, 2007), dealing with the striking similarities between the Stanford Prison Experiment and the Abu Ghraib abuses.