Would you kill somebody if you were told to by your boss or an authority figure? "Of course not. Are you nuts?" is probably the most common answer to this question. However, this can not be backed up with psychological research carried out in the sixties and seventies.
After Nazi-Germany had collapsed and the world started to realize the unbelievable things that had happened, a lot of sociological and psychological experiments were carried out to understand if, how, and when ordinary people lose their humanity.