Philip Zimbardo and his team aimed to demonstrate the situational rather than the dispositional causes of negative behaviour and thought patters found in prison settings by conducting the simulation with average everyday participants playing the roles of guard and prisoner. From a total of seventy-five volunteers, twenty-two male participants were selected based on maturity, stability and lack of involvement in anti-social behaviour. These participants were predominantly white and middle-class. The participants were randomly to either prison or guard roles and were all strangers to each other. Those allocated to prisoner roles were required to sign a consent document which specified that some of there human rights would suspended and that all participants would receive a sum of fifteen dollars a day for up to two weeks.
The prison itself was in the basement corridor of the Stanford Psychology Department, which had been converted a set of 2 x 3 metre prison cells with a solitary confinement room converted from a tiny unlit closet. An undergraduate research assistant was the "warden" and Zimbardo the "superintendent". He set up a number of specific conditions for the participants which were intended to promote disorientation, depersonalization and deindividuation.
To facilitate role identification, guards were given wooden batons and akhaki, military-style uniforms. They were also given reflecting sunglasses to prevent eye contact. Unlike the prisoners, the guards were to work in shifts and return home afterwards which added to the reality of the role. Although given