A criticism of Milgram's study is its ethical issues, particularly deception and psychological harm. Participants were misled to believe they were administering real shocks, which led to intense stress and emotional discomfort for some. Also, this deception means that Milgram failed to get informed consent from his participants which violates ethical guidelines. This weakens Milgram's study as it can be argued that ethical guidelines should be followed at all times, and participants should never be put in harm for the sake of research.