The Milgram experiment certainly has its ethical concerns, but I believe the benefits to psychology outweigh this. By use of a cost:benefit ratio, myself and a fellow student discussed that while there were obvious ethical issues of deception and possible psychological harm to participants, there were a number of benefits: 1) The participants were immediately debriefed, and had the right to withdraw their results if they wanted to. 2) Milgram met with the participants one year later to see if there was any harm caused. Many reported the experiment taught them more about themselves. 3) The participants were allowed to meet the person they "electrocuted," so they would see there was no harm. To name the first few that spring to mind.

1) Yes, it is a quite famous experiment. The Wikipedia article gives a lot of very interesting information about it: http://en.wikipedia.org/wiki/Milgram_experiment 2) Admitedly, this experiment is ethically somewhat questionable. But most people obviously had no idea about what the results would be, as showed a pool made before the experiment took place. Maybe we could have discovered this facts with a more ethical experiment. They did not either try to find a better way to do it as they repeated the experiment. Would you have an idea how to make it better? 3) On the positive side, the results were of extremely important interest for social psychology and ethics. 4) much more ethically questionable is the following: "The Stanford prison experiment was a psychological study of what it meant to be a prisoner and a prison guard, psychologically. The experiment was conducted in 1971 by a team of researchers led by psychologist Philip Zimbardo at Stanford University. Twenty four undergraduates were selected out of 70 to play the roles of both guards and prisoners and live in a mock prison in the basement of the Stanford psychology building. The students who were assigned to be the prisoners were paid $15 dollars a day as an incentive. Prisoners and guards rapidly adapted to their roles, stepping beyond the boundaries of what had been predicted and leading to dangerous and psychologically damaging situations. One-third of the guards were judged to have exhibited "genuine" sadistic tendencies, while many prisoners were emotionally traumatized and two had to be removed from the experiment early. Finally, Zimbardo terminated the experiment because he realized that his experiment was unethical. Ethical concerns surrounding the famous experiment often draw comparisons to the Milgram experiment, which was conducted in 1961 at Yale University by Stanley Milgram, Zimbardo's former college friend. Tom Peters and Robert H. Waterman Jr wrote in 1981 that the Milgram Experiment in the 1960s and the later Zimbardo Experiment were frightening in their implications about the danger which lurks in the darker side of human nature." Source and further information: http://en.wikipedia.org/wiki/Stanford_prison_experiment This experiment inspired also a movie: http://en.wikipedia.org/wiki/Das_Experiment