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Stanford Prison Experiment


Carried out August 15-21, 1971 in the basement of Jordan Hall, the Stanford Prison Experiment set out to examine the psychological effects of authority and powerlessness in a prison environment. The study, led by psychology professor Philip G. Zimbardo, recruited Stanford students using a local newspaper ad. Twenty-four students were carefully screened and randomly assigned into groups of prisoners and guards. The experiment, which was scheduled to last 1-2 weeks, ultimately had to be terminated on only the 6th day as the experiment escalated out of hand when the prisoners were forced to endure cruel and dehumanizing abuse at the hands of their peers. The experiment showed, in Dr. Zimbardo’s words, how “ordinary college students could do terrible things.”

Researchers: Philip Zimbardo, Craig Haney, W. Curtis Banks, David Jaffe

Primary Consultant: Carlo Prescott

Additional research assistance, clerical assistance, and critical information provided by: Carolyn Burkhart, David Gorchoff, Christina Maslach, Susan Phillips, Anne Riecken, Cathy Rosenfeld, Lee Ross, Rosanne Saussotte, and Greg White.

Prison constructed by: Ralph Williams, Bob Zeiss, Don Johann

Police cooperation through: James C. Zurcher, Chief of Police, City of Palo Alto Joseph Sparaco, Officer, Police Department, City of Palo Alto Marvin Herrington, Director of Police, Stanford University