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Zimbardo's Stanford Prison Experiment

Zimbardo's Stanford prison experiment revealed how social roles can influence our behavior. We look at how it was conducted and what we can learn from it.

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Zimbardo's Stanford Prison Experiment

PrisonThe Stanford Prison Experiment was a landmark psychological study of the human response to captivity, in particular, to the real world circumstances of prison life. It was conducted in 1971 by Philip Zimbardo of Stanford University.


Subjects were randomly assigned to play the role of "prisoner" or "guard". Those assigned to play the role of guard were given sticks and sunglasses; those assigned to play the prisoner role were arrested by the Palo Alto police department, deloused, forced to wear chains and prison garments, and transported to the basement of the Stanford psychology department, which had been converted into a makeshift jail.

Several of the guards became progressively more sadistic - particularly at night when they thought the cameras were off, despite being picked by chance out of the same pool as the prisoners.

The experiment very quickly got out of hand. A riot broke out on day two. One prisoner developed a psychosomatic rash all over his body upon finding out that his "parole" had been turned down. After only 6 days (of a planned two weeks), the experiment was shut down, for fear that one of the prisoners would be seriously hurt.

Although the intent of the experiment was to examine captivity, its result has been used 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 seniority/authority.

It can be argued that the conclusions that Professor Zimbardo and others have drawn from the Stanford Prison Experiment are not valid. Professor Zimbardo acknowleges that he was not merely an observer in the experiment but an active participant and in some cases it is clear he was influencing the direction the experiment went.

For example, Professor Zimbardo cites the fact that all of the "guards" wore sunglasses as an example of their dehumanization. However, the sunglasses were not spontaneously chosen as apparel by the students; they were given to them by Professor Zimbardo. The student "guards" were also issued batons by Professor Zimbardo on their first day, which may have predisposed them to consider physical force as an acceptable means of running the "prison".

Professor Zimbardo also acknowleges initiating several procedures that do not occur in actual prisons, such as blindfolding incoming "prisoners", making them wear women's clothing, not allowing them to wear underwear, not allowing them to look out windows, and not allowing them to use their names. Professor Zimbardo justifies this by stating that prison is a confusing and dehumanizing experience and it was necessary to enact these procedures to put the "prisoners" in the proper frame of mind. However, it opens the question of whether Professor Zimbardo's simulation is an accurate reflection of the reality of incarceration or a reflection of Professor Zimbardo's preconceived opinions of what actual incarceration is like.

Does Zimbardo's study explain Abu Ghraib abuse?

The human rights abuses that occurred at the Abu Ghraib prison under the authority of the American armed forces in the aftermath of the 2003 Iraq war may be a recent example of what happened in the experiment in real life. Soldiers were thrust into the role of prison guards and began to sadistically torment prisoners there and at other detention sites in Afghanistan and Iraq. Many of the specific acts of humiliation were similar to those that occurred in the Stanford Prison Experiment, according to Zimbardo.

This theory has been challenged by allegations by Seymour Hersh in the New Yorker that these soldiers were in fact acting under direct orders of their superiors as part of a top secret Pentagon intelligence gathering program authorized by Secretary of Defense Donald Rumsfeld.

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