Robert Jay Lifton is an American psychiatrist and author, chiefly known for his studies of the psychological causes and effects of war and political violence.
Author of "The Nazi Doctors: Medical Killing and the Psychology of Genocide", the first in-depth study of how medical professionals rationalized their participation in atrocities like the Holocaust, from the early stages of the T-4 Euthanasia Program to the extermination camps.
His studies of the behavior of people who had engaged in torture and/or war crimes, both individually and in groups, concluded that such crimes do not require any unusual degree of personal evil or mental illness, and are nearly sure to happen given certain conditions (either accidental or deliberately arranged) which Lifton called "atrocity-producing situations".