What did Stanley Milgram's obedience study reveal about human behavior?

Stanley Milgram's 1963 experiment tested how far ordinary people would go in obeying an authority figure's instructions to harm another person. Participants were told to administer increasing electric shocks to a confederate learner for wrong answers, up to a potentially lethal 450 volts. Approximately 65 percent of participants delivered the maximum shock level despite the learner's screams and pleas to stop. Milgram demonstrated that obedience to authority is a powerful social force that can override personal moral judgment.