In The '60s, A Yale Psychiatrist Conducted Shocking Experiments. He Didn't Expect What Happened Next

Would you inflict pain on someone you didn't know, who was undeserving of the punishment? You probably think you wouldn't, even if someone in authority ordered you to do so. However, an experiment carried out by Stanley Milgram in the 1960s suggested otherwise, when a staggering 65% of participants sent what they believed to be 450 volts of electric shock through a stranger's body, simply because they were told to.

Milgram was an American social psychologist who was intrigued by the behavior of Germans during WWII and wanted to investigate whether a uniquely German trait caused them to enact such atrocities when ordered to. His research was one of several social psychology studies examining the effects of authority, predating the famous Stanford prison experiment which came a decade later. Milgram's initial plan was to test American participants to establish a control group with low obedience, but his results utterly shocked him — pun very much intended.

His pool of participants consisted of 40 males aged between 20 and 50 years old, who thought the research was studying the effects of punishment on learning. They believed they were randomly chosen to play the role of "teacher" while a fellow participant was the "learner," when in truth it was an actor playing opposite them. The teacher had the power to send electric shocks to the learner whenever they answered a question wrongly, with the voltage increasing each time. After discussion with senior psychology students from Yale university, Milgram expected only around 1% of the participants to administer the full voltage of 450 volts, especially since they could hear the learners screams as the voltage increased. But he couldn't have been more wrong.

The study, titled Behavioral Study of Obedience was published in 1963 in the Journal of Abnormal and Social Psychology. For the main experiment, the teacher was instructed by the "experimenter", also an actor, to administer a shock to the learner whenever an incorrect answer was given. The teacher had been exposed to a sample shock of 45 volts before the experiment began to convince them the set up was genuine, which was 10% of the voltage of the maximum possible shock that could be applied to the learner by the end of the experiment.

Whenever a participant hesitated at the thought of delivering the next level of shock, the experimenter prodded them with pre-scripted phrases, starting with "Please continue," and increasing to "You have no other choice but to continue." In contrast with Milgram's assumptions of a low-obedience control group, every single participant "delivered" up to 300 volts of shock to their counterpart, albeit in some cases following a protest to the experimenter. Five of the "defiant" participants felt that 300 volts was punishment enough and stopped there, while nine others continued further but stopped short of the maximum.

To Milgram's amazement, the remaining 26 teachers completed the experiment, believing they had delivered a shock of 450 volts to their fellow participant. While they had been reassured by the experimenter that the shocks would be painful rather than dangerous, the machine they were controlling was marked "XXX" for the last two settings. Coupled with the learner warning of a heart condition at 150 volts and pounding on the wall when the shocks reached 300 volts, the participants had plenty of reason to question the safety of the shocks they were providing.

The unexpected results from his experiment caused Milgram to abandon his original project comparing American and German participants, but he did conduct numerous follow up trials with different variables. This included replacing the authoritative experimenter with a civilian at the last minute, which caused obedience to drop dramatically; and adding two additional (fake) teachers into the room, who refused to cooperate early on in the experiment. In this version compliance dropped to just 10%, showing the influence of social pressure on the participants' behavior.

In a shocking twist, one follow-up experiment found that if the participant was able to delegate the actual pressing of the button to an assistant, 92.5% delivered the full 450 volts, suggesting that someone else inflicting the harm places much less moral responsibility on the shoulders of the decision maker.

Milgram's research became one of numerous highly controversial psychological experiments of the 1960s, mainly due to the ethics of the experiment. Descriptions of the participants included sweating, trembling, and in one case becoming, according to Milgram, "[a] twitching stuttering wreck." Aware of the criticism, Milgram followed up with the participants, and claimed that 83.7% of them said they were glad to take part. Milgram observed that many of the participants were clearly "acting against their own values," and their body language suggested that they knew what they were doing was morally wrong. In spite of this, they continued to (supposedly) inflict pain on a stranger, simply because someone they believed to be in authority told them to do so. This series of experiments shows how strongly social pressure can influence our decisions, and can even overpower our own moral compass.