The psychoanalysis of Nazis buttresses the findings already made about the banality of evil. Ben Cohen explores Evil and Id in Jewish Ideas Daily:

Landing by parachute unannounced, Hess hoped to engineer a peace settlement to neutralize the Western front, thereby enabling Germany to focus on its offensive against the Soviets. Expecting passage to Churchill's office, Hess was instead placed under the watchful eye of Dr. Henry Dicks, a prominent army psychiatrist. Over the next four years, in Scotland, London, and Wales, Hess became a one-man laboratory for the study of Nazism at the level of the subconscious.

 

Hess proved an irritating composite of eccentric and neurotic personality types, an infantile baby and an inhuman brute.  Pick describes a man obsessed with herbs and potions, in thrall to the occult ideas of the hyper-nationalist, anti-Semitic Thule Society, which he joined as a young man. He claimed amnesia (“if I got my memory back, I would suffer more”) and saw Jewish conspiracies everywhere he looked.  To top it all off, he was given to tantrums and other histrionic displays, which his captors, in classic British style, tried to soothe with endless cups of tea.