The quiet Sunday morning of August 14, 1971, was broken by the wail of sirens as the Palo Alto, California police swept through town arresting nine people. The suspects were handcuffed, read their rights and subjected to the degradation of the booking process after being transported to the Stanford County Prison (SCP). So began the Stanford Prison Experiment (SPE), one of the most important psychology experiments in this country’s history
The Stanford prison experiment was a study of the psychological effects of becoming a prisoner or prison guard. The experiment was conducted from August 14–20, 1971 by a team of researchers led by psychology professor Philip Zimbardo at Stanford University. It was funded by a grant from the US Office of Naval Research and was of interest to both the US Navy and Marine Corps in order to determine the causes of conflict between military guards and prisoners.
Twelve students were selected out of 75 to play the prisoners and live in a mock prison in the basement of the Stanford psychology building. Another twelve of the same 75 were selected to play the Guards. Roles were assigned randomly to the 24 men. The participants adapted to their roles well beyond what even Zimbardo himself expected, leading the officers to display authoritarian measures and ultimately to subject some of the prisoners to torture. In turn, many of the prisoners developed passive attitudes and accepted physical abuse, and, at the request of the guards, readily inflicted punishment on other prisoners who attempted to stop it. The experiment even affected Zimbardo himself, who, in his capacity as Prison Superintendent, lost sight of his role as psychologist and permitted the abuse to continue as though it were a real prison. Five 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 made publicly available.