A01

• Zimbardo's study aimed to investigate the roots of prison brutality, questioning whether it stemmed from inherent sadism or social roles. In his experiment, 21 emotionally stable men were randomly assigned as prisoners or guards in a simulated prison at Stanford University.
• Uniforms stripped individuals of personal identity (deindividuation), fostering conformity to assigned roles. Prisoners wore smocks and numbered caps, while guards wore authoritative attire with accessories like mirror shades, handcuffs and clubs. Instructions reinforced role adherence; prisoners could only leave by applying for parole, and guards were told they had complete power over prisoners.
• The findings showed that guards quickly adopted oppressive behaviours, met with prisoner rebellion within days. The power imbalances grew through constant harassment and punishments. Rebellion led to prisoner distress, with some exhibiting psychological symptoms as they became depressed and anxious.
• As the study progressed, guards' brutality intensified, finding joy in their dominance. Zimbardo halted the study prematurely due to escalating aggression after only six days. The findings show the profound influence of social roles on behaviour, as participants readily embraced assigned roles.