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 psychologist Philip
Zimbardo at Stanford
University. Twenty-four undergraduates were selected out of 70 to play the
roles of both guards and prisoners and live in a mock prison in the basement
of the Stanford psychology building. Those selected were chosen for their lack
of psychological issues, crime history, and medical disabilities, in order to
obtain a representative sample. Roles were assigned based on a coin toss.
Prisoners and guards rapidly adapted to their roles, 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 and two had to be removed from the experiment early. After a graduate student Zimbardo was dating objected to the inhumane conditions in the prison, and realizing that he had been passively allowing unethical acts to be performed under his direct supervision, Zimbardo concluded that everyone including himself had become too absorbed in their roles and terminated the experiment after six days.
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 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.
A false rumor spread that one of the prisoners, who asked to leave the experiment, would lead companions to break the rest of the prisoners. The guards were forced to dismantle the prison and move 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 homosexual sex.
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. Interestingly, 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, 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.