What are the ethical limitations of Milgram's studies on obedience to authority?

- Long-term psychological harm to participants - some participants reported psychological problems following the traumatic events of the study. There was also no period of debriefing following experiments, increasing the likelihood of psychological harm.

- Deception - participants were led to believe that the study was on learning, when it was in fact on obedience to authority. Participants further were not aware that there was no 'learner' in the other room and that the audio they heard was a recording. Moreover, some of Milgram's replications of the study used confederates.

- Participants not given the right to withdraw - whilst Milgram did allow some insistent participants to withdraw from the study, the right to withdraw was not made clear. When participants resisted the experimenter would repeat 'the experiment requires that you continue', which implied that participants had no right to withdraw.