The Stanford Prison Experiment

The Stanford Prison Experiment assigned 24 college students to be guards or prisoners in a mock basement prison for two weeks, but within 36 hours, guards were psychologically torturing prisoners. One prisoner had a breakdown on Day 2, and the study was terminated after six days, revealing an 80% rate of abusive behavior among guards. This became the most cited psychology study of the 20th century, 40% more influential than #1's CRISPR in social science impact. Later research questioned whether Zimbardo coached the cruelty, but either way, it changed how we think about power forever, generating 10,000 follow-up studies since 1971.