The document summarizes Philip Zimbardo's infamous Stanford prison experiment from 1971. In the experiment, volunteer students were randomly assigned to be prisoners or guards in a mock prison setup in the basement of the Stanford psychology building. The experiment was intended to last two weeks but had to be stopped after only six days because things had spiraled out of control. Both the prisoners and guards had begun to take on their roles too seriously, with guards exhibiting increasingly authoritarian and abusive behavior and prisoners showing signs of extreme stress and emotional breakdown. While the experiment yielded important insights into group dynamics and conformity, it violated ethical standards in subjecting participants to psychological harm without their full consent.