15 Most Disturbing Experiments in Human History

3. Stanford Prison Experiment

Conducted in 1971, the Stanford Prison Experiment stands as one of the most controversial studies ever done. In an attempt to understand why prison guards and prisoners repeatedly come into conflict with each other, psychology professor Philip Zimbardo drafted 24 males for a one to two week experiment. One half of the men were given the role of guard; the other half were assigned the role of prisoner. The results were shocking, as guards began to psychologically torment the prisoners, who suffered their own mental anguish. The experiment was halted abruptly after 6 days.