The teachers were instructed by the experimenter to administer increasingly higher voltages to the learner with successive wrong answers. .
The learners were actually part of the experimention team. No shocks were actually delivered to the learners, but they were trained to convincingly act as if they were suffering from the escalating shock levels administered by the teachers. Although the experimenter did nothing more than encourage the teachers to continue, and then only after the teacher protested, every teacher in the experiment administered shock levels up to 300 volts, high enough that the learner appeared to be in extreme pain. More surprisingly, two-thirds of the teachers continued administering shocks all the way to the maximum 450-volt level, the level at which the learners appeared to have become unconscious with pain. .
Milgram came to a variety of conclusions concerning the obedience to authority shown in his experiments. The teachers had volunteered to participate in this experimentation, and this effectively created a contract with the experimenter that the teachers would be cooperative in following his instructions. Teachers were also faced with either obeying the experimenter's instructions or seeming impolite or uncooperative, as refusing to obey was tantamount to calling the experimenter immoral. These social norms clearly exerted subtle pressure on the teachers to follow orders by making it more uncomfortable for them to refuse. .
The fact that the shocks were administered in a progressive way is also important. Once a person crosses the line of giving another person the low-voltage shocks, it is apparently easier to rationalize pushing the line through progressively more severe punishment. The stopping point becomes obscured for the teachers. By stopping, a teacher would have to realize that if there is any stopping point at all, it would have to be before they ever started.
