Weaknesses (Cont.): Afterwards, this view of themselves was shattered. Milgram argued that such self-knowledge was valuable. A year after the experiments an independent psychiatrist interviewed 40 of the participants (many of whom had experienced extreme stress), and found no evidence of psychological harm or evidence of traumatic reactions. In terms of the right to withdraw, it was good that Milgram stated at the start that the money paid to the participants was theirs regardless of whether they continued with the experiment. However, during the experiment the prods used suggested that withdrawal was not possible. This is ethically incorrect. Even so, we should consider whether the experiment would have been valid if the experimenter kept reminding the participant about his right to withdraw. A major criticism of Milgram’s study was his unrepresentative sample. Milgram chose to study only American men (thus he was deliberately ethnocentric), but from a variety of backgrounds and different ages. It could be argued that by using men this produced a sample that was biased, or did not reflect the general population. The study was also limited to those people who read the advertisement and were prepared to participate in a laboratory experiment. These men who replied may have been somehow different from the general population. Because of such an unrepresentative sample the results cannot be generalised to all people. Despite this, Milgram concluded that ‘obedience to authority is not a feature of German culture but a seemingly universal feature of human behaviour’. A number of cross-cultural replications of Milgram’s experiment have been done (e.g. Italy and Australia) gaining similar results. Another main criticism of Milgram’s experiment was that it was not ecologically valid. It can be argued that Milgram’s work was carried out in an artificial setting and has little relevance to the real world.