Participants
There were male 30 participants participating. They were recruited by advertisement in a newspaper and were paid $4.50.
Instruments
A "shock generator" was used to trick the participants into thinking that they gave shock to another person in another room. The shock generator had switches labeled with different voltages, starting at 30 volts and increasing in 15-volt increments all the way up to 450 volts. The switches were also labeled with terms which reminded the participant of how dangerous the shocks were.
Procedures
The participant met another "participant" in the waiting room before the experiment. The other "participant" was an actor. Each participant got the role as a "teacher" who would then deliver a shock to the actor ("learner") every time an incorrect answer was produced. The participant believed that he was delivering real shocks to the learner.
The learner was a confederate who would pretend to be shocked. As the experiment progressed, the teacher would hear the learner plead to be released and complain about a heart condition. Once the 300-volt level had been reached, the learner banged on the wall and demanded to be released. Beyond this point, the learner became completely silent and refused to answer any more questions. The experimenter then instructed the participant to treat this silence as an incorrect response and deliver a further shock.
When asking the experimenter if they should stop, they were instructed to continue.