With the primary goal of testing obedience in mind, Milgram built a shock control box with 30 switches and collected subjects to act as teachers and learners. Subjects were chosen from many types of individuals, all of them normal, healthy adults. During the course of his experiments, Milgram performed about 20 studies, using different subjects each time, without much fluctuation in results, according to "The New York Times." Though his first studies included only men, later studies would include women with little or no variation in results.
Those subjects designated as teachers were tasked with administering shocks to those designated as learners. Though these shocks began at very low voltages, they appeared to grow increasingly more powerful until reaching simulated 450-volt shocks, which would if real have been lethal. Though saying "no" to the test administrators and refusing to shock the learners was an option, most teachers who continued to administer shocks did so to appear agreeable or out of fear of authority figures, who assured them that everything would be OK as long as they continued to administer shocks. According to Philip Zimbardo, social psychologist famous for his Stanford Prison experiment and author of a study on the psychology of evil, many teacher subjects would continue to administer shocks as long as they could be assured that they would not be held responsible.
The experiment was arranged so that there were no actual randomly selected learners. The experiment's "learners" were actors who behaved so that the randomly selected teacher subjects would be given the opportunity to continue shocking them as punishment for providing wrong answers to questions. Actors "protested" the treatment, and once a teacher had administered shocks up to 330 volts, the actor would refuse to answer more questions. When actors refused to answer, teachers were given the opportunity to increase the voltage of the shocks, even knowing, because of warnings on the shock box, that 450-volt shocks were lethal.
According to Milgram expert Dr. Thomas Blass, 65 percent of subjects proved willing to take the orders of a perceived authority figure and administer deadly shocks of what they thought were up to 450 volts. Because so many subjects were willing to take orders and shock the learners, Milgram's study has led thousands to question whether they, themselves, would have taken the orders and administered the shocks. Milgram's study demonstrates the psychological, ethical and physical willingness to forgo autonomous decision-making in favor of following orders, even when those orders can hurt others. It also shows that authority, or the perception of authority, has a powerful affect on everyday people, and that one need not be deviant or mentally ill to follow authority figures to extremes.