Zimbardo

• Aim: Zimbardo set up a mock prison in the basement of the psychology department at Stanford university to investigate the effect of social roles on conformity
• 21 male student volunteers were involved in the study - selected by psychological testing that showed them to be emotionally stable. They were randomly allocated to the role of guard or prisoner
• Uniform:

  Prisoners were strip searched, given a uniform and number (no names), this encourages de-individualisation. Guards enforced rules, had own uniform with handcuffs
• Instructions about behaviour:

  Prisoners were told that they could not leave but would have to ask for parole. Guards were told they had complete power over prisoners
• Social roles were encouraged by 2 routes - uniform and instructions about behaviour
• The guards played their roles enthusiastically and treated prisoners harshly. The prisoners rebelled within 2 days - they ripped their uniforms, shouted and sworn at guards. The guards had retaliated with fire extinguishers and harassed the prisoners - reminder of their powerless role
• Zimbardo found the guards behaviour threatened the prisoners psychological and physical health. The study was stopped after 6 days instead of the planned 14 days
• After the rebellion was put down, the prisoners became subdued, anxious and depressed
• The prisoners were released early because they showed signs of psychological disturbance
• One prisoner went on hunger strike; the guards attempted to force-feed him and punished him by putting him "in the hole", a tiny dark closet
• Social roles are powerful influences on behaviour - most conformed strongly to their role. Guards became brutal, prisoners became submissive. Other volunteers also easily conformed to their roles in the prison
• One strength is the control over key variables. Emotionally stable participants were recruited and randomly allocated the roles of guard or prisoner. The guards and prisoners had those roles only by chance. So their behaviour was due to the role itself and not their personalities. This control increases the study's internal validity, so we have more confidence in drawing conclusions about the effect of social roles on conformity
• One limitation is the SPE lacked the realism of a true prison. Banuazizi and Mohavedi suggest participants were play acting. Their performances reflected stereotypes of how prisoners and guards are supposed to behave. One guard based his role on a character from the film Coal Hand Luke. Prisoners rioted because they thought that is what real prisoners did. This suggests the SPE tells us little about conformity to social roles in actual prisons
• A counterpoint to the lack of realism of a true prison is that participants behaved as if the prison was real e.g: 90% of conversations about prison life, prisoner 416 believed it was a prison run by psychologists. This suggests the SPE replicated the roles of guard and prisoner just as real prison, increasing internal validity
• One limitation is that Zimbardo exaggerated the power of roles. The power of social roles to influence behaviour may have been exaggerated in the SPE. Only 1/3 of the guards behaved brutally. Another 1/3 applied the rules fairly. The rest supported the prisoners, offering them cigarettes and reinstating privileges. This suggests the SPE overstates the view that guards were conforming to a brutal role and minimised dispositional influences