Zimbardo’s Stanford Prison Experiment

zimbardo's prison experiment - set up

a mock prison in stanford uni basement. 21 male student volunteers who were tested as 'emotionally stable'. randomly assigned to prisoner or guard. the prisoners were fake arrested from the homes

uniforms of prisoners

loose smock and a cap to cover hair, they were also indentified by their numbers

uniform - guards

had wooden clubs, handcuffs and mirror shades.

purpose of uniform

uniforms were meant to cause de-individuation/loss of personal identity

zimbardo's prison experiment - procedure

they were encouraged to identify with their roles. the guards took their roles quickly & treated prisoners harshly. within 2 days the prisoners rebelled, ripped their uniforms and swore at the guards.
guards responded with fire extinguishers and used 'divide and rule' tactics on prisoners, reminding them they were powerless through head-counting their numbers.

how were the participants encouraged to identify with their roles

• prisoners had to ask for parole rather than to leave the study
• guards were reminded that they had complete control over the prisoners.

zimbardo's prison experiment - findings

prisoners became depressed and anxious. one was released on day 3 since he showed signs of psychological disturbance. 2 more were released on day 4. one went on a hunger strike, guards tried to force feed him before locking him in a tiny closet. guards became increasingly aggressive

zimbardo's prison experiment - conclusion

social roles seem to have strong influence on behaviour - guards became aggressive and prisoners became submissive.

strength of zimbardo's prison experiment - control variables

they had good control over key variables. they chose a selection of emotionally stable participants who were randomly assigned to roles. this reduces the individual differences, therefore increases internal validity

limitation of zimbardo's prison experiment - unrealistic

as it wasn't a real prison with real guards and prisoners, participants may have been acting rather than conforming to their roles. participant's performances may have been based on stereotypes, e.g. one participant based his behaviour off a film.

limitation of zimbardo's prison experiment - results were exaggerated

only 1/3 acted brutally, 1/3 tried to apply rules fairly and 1/3 tried to support the prisoners.

limitation of zimbardo's prison experiment - ethical issues

many participants suffered distress and psychological disturbance, so much so they had to leave on day 3 and the study was cut short. therefore the study violates protection from harm.