The Stanford prison experiment (1973)

• A mock prison was set up in the basement of the psychology department at stanford university in California
• Male student volunteers were psychologically and physically screened and the 24 most stable of these were randomly assigned to either play the role of prisoner and guard
• The prisoners were unexpectedly arrested at home and on entry to the prison were put through a deli using procedure, given a uniform and assigned an ID number
• Participants allocated the role of guard were given uniforms, clubs, whistles and reflective sunglasses
• Zimbardo took the role of prison superintendent
• Over the first few days the guards grew increasingly hostile towards the prisoners and appeared to forget at times that they were in a study and were merely acting
• Five prisoners had to be released early because of the extreme reactions and study was terminated after just six days following the intervention of a post graduate student who was later to become zimbardos wife
• This study demonstrated that both prisoners and guards conformed to their social roles
• The guards became increasingly cruel and sadistic and the prisoners became increasingly passive and accepting of their plight
• Banuazizi and Movahedi (1975) argued that the behaviour of ps in the SPE was more a consequence of demand characteristics than conformity to roles which suggests that the behaviour of Zimbardo’s guards and prisoners wasn’t due to their response to a ‘compelling prison experiment‘, rather it was a response to powerful demand characteristics in the experimental situation itself
• Haslam and Reicher (2012) challenged Zimbardo’s belief that the guards drift into sadistic behaviour was an automatic consequence of them embracing their role. They pointed out that guard behaviour varied from being fully sadistic to being good guards who didn’t degrade or harass the prisoners and even did small favour for them which shows that the guards chose how to behave instead of blindly conforming to their social roles
• Zimbardo acknowledges that perhaps the study should’ve been stopped earlier since so many ps were experiencing emotional distress. He attempted to make amends for this by carrying out debriefing sessions for several years afterwards and concluded that there weren’t any lasting effects