The men who answered the ad thought they were signing up for a study of memory and learning at Yale. They came from New Haven and the towns around it: postal clerks, teachers, salesmen, engineers, laborers. Each was paid $4.50 and told the money was his just for coming, whatever happened next.
There was a second volunteer, a 47-year-old accountant whom most observers found mild-mannered and likable. The two drew slips from a hat to decide who would be the teacher and who the learner. Both slips said “Teacher.” The other man, an accomplice trained for the role, became the learner. He was strapped into a chair in the next room, and electrode paste was applied “to avoid blisters and burns.”
The teacher sat at a simulated shock generator (the learner never actually received a shock, though the teacher believed he did) with 30 switches, from 15 volts to 450, labeled from Slight Shock to Danger: Severe Shock. Every wrong answer meant one switch higher. At 300 volts, the learner pounded on the wall. After 315 he went silent, and his answers stopped coming.
When a teacher hesitated, the experimenter, a 31-year-old biology teacher in a gray technician’s coat, had four lines, used in order: “Please continue.”“The experiment requires that you continue.”“It is absolutely essential that you continue.”“You have no other choice, you must go on.” By the rules, if a teacher still refused after the fourth, the session ended.
Milgram had given 14 Yale psychology seniors a full description and asked how 100 ordinary Americans would behave. Their estimates ranged from 0 to 3 who would go all the way. The average was 1.2.
No one stopped before 300 volts. Five stopped there. In the end 26 of the 40 men went to the last switch, two steps past Danger: Severe Shock.
Many did it under visible strain. They sweated, trembled, stuttered and dug their nails into their own flesh. Fourteen broke into nervous laughter. In three, the laughter became full, uncontrollable seizures, one so violent, in a 46-year-old encyclopedia salesman, that the session was called off. One observer described a businessman who came in “smiling and confident” and within 20 minutes was “a twitching, stuttering wreck.” At one point he pushed his fist into his forehead and muttered, “Oh God, let’s stop it.”
“And yet he continued to respond to every word of the experimenter, and obeyed to the end.”
People watching through one-way mirrors, who knew every detail of the setup, often reacted with disbelief as the shocks went higher.
When the last switch had been thrown and the experimenter called a halt, many of the obedient men sighed with relief, mopped their brows or fumbled for cigarettes. Some shook their heads, Milgram wrote, apparently in regret.