Case Study
Stanford Prison Experiment
Philip Zimbardo, for the US Office of Naval Research, 1971
Philip Zimbardo recruited 24 college students for a two-week mock-prison simulation, randomly assigning half to role-play prisoners and half to role-play guards, with guards given uniforms, wooden batons, and the honorific "Mr. Correctional Officer."
Result: within a day, guards moved past initial awkwardness into progressively more tyrannical behavior — locking "rebellious" prisoners in cupboards, removing beds, threatening food deprivation, and forcing prisoners to strip, recite poetry backwards, and simulate degrading acts. Prisoners, despite knowing it was only a study, gradually stopped resisting and complied with escalating, unjust treatment. Zimbardo halted the experiment after six days, well short of its planned two weeks, after his own girlfriend's reaction to observing it convinced him it had gone too far. Cited alongside the Milgram obedience experiments as a foundational demonstration of Authority Bias — ordinary people rapidly adopting extreme behavior once placed in a role with institutionally sanctioned power, or once subjected to one.
Discussed in
- Episode 196 — 196-7-cognitive-biases-that-might-ruin-your-life