Good question. Being German I've read and watched a lot about this subject but have never found a satisfactory answer. However, we shouldn't equate intelligent with good or human. You can be extremely clever and a criminal at the same time. I once read that the professional groups who first joined the NSDAP were teachers, doctors, lawyers, in short, educated people. Some of the scientists working in the camps saw their chance of doing "research" unimpeded by any ethical laws and regulations. Their curiosity overruled any moral instinct. And the Nazi system used them for its own purposes. 
 

It is a very emotive subject. I actually found the character of Colonel Hans Landa (played by Christoph Waltz) in Inglorious Basterds to be spot on as to be an explanation of the mind set. The scene where he is talking, oh so reasonably, to the French farmer and using the analogy of rats, is a clear explanation. The reasoning behind not only the Holocaust but also the 'treatment' of groups other than the Jews  (such as the Gypsies, homosexuals, Slavs, the disabled and mentally ill) is based upon the premise that they are 'sub-human' and conspiracy theories. The hatred and revulsion is based upon 'big lies'. If you can sell 'big lies' to the populace then the 'logic' that flows from these is self-sustaining.

I have no doubt that what HItler did was evil and that he had become an evil person. But I don't believe that he was just born like that; people aren't born with the desire to kill millions of others. It's not something that an average person would do. Maybe he had severe problems with empathy but I don't believe that he was just born as an evil man. I don't mean to sound in any way supportive of what he did at all; I just think that it's a pretty insane thing to do that probably has some explanation other than him just being a horrible person.

The parallels you draw with cults are, I believe, very valid. If I may I'd like to explore these a little further and draw not only upon The Third Reich but also other regimes.

They have a charismatic leader. Hitler was, without doubt charismatic; listen to his speeches, watch him 'perform' if you are in any doubt of this. Cult leaders, including those within the higher echelons of power, know how to manipulate people; witness the rallies of Mussolini and their adaptation and expansion by the Nazis. Cult leaders know how to manipulate those who they have in their command structure; how to flatter, reward, motivate, threaten and, when necessary, eliminate.

The other similarity is the way in which the 'state' or the 'cult' becomes a substitute for family and normal society; people are expected to work for the benefit of the Nation or the cult- this may include physical work, producing children, worship of the cult leader(s) etc.

A further similarity is that those within the cult or the 'master race', or the Red Guard or the Khmer Rouge etc. are in positions of power and superiority they are an elite; those outside are powerless and inferior/sub-human etc. the same also in such events as the Rwandan  genocide and ethnic cleansing in the former Yugoslavia.

It is valid also to examine the psychological make-up of those who become cult leaders or the leaders of totalitarian states such as Hitler, Stalin, Mussolini, Pol Pot etc. and those within their command structure.

Simply seeing these people, and those who colluded with them or who actively took part in genocide and other atrocities, as 'monsters' is, I feel, an over-simplification. It also holds the danger of lulling us into the false sense of security that, of course, such things could not happen 'here' (where ever 'here' may be). One only has to read studies of experiments, or even to watch programmes such as those Derren Brown has made, to see that, in fact, people are very easily manipulated; within a group will act in ways they would never do individually and how soon they can be made to feel superior or inferior to others and how their behaviour changes as a result.

I agree, Molly, that Hitler was unlikely to have been born evil. If one reads his biographies or Mein Kampf (even the title is revealing) then one can see certain key events that went to form his psychology. These, combined with historical events and the number of other men of a similar mind-set, worked together to create the Third Reich and all its subsequent systematic atrocities.

Hitler and most of his cronies, like many cult leaders, committed suicide in the final days of the Third Reich- many took their children with them. Another parallel with cults.

I seem to have written a mini-essay here. What do you folks think?

I don't really have a 'good' answer either… (or, heck, any kind of expertise at all claimed on the man or history/human psychology aside from a somewhat unrelated family-country connection, with grandfather having talked about his (non-jewish) family getting out of Germany in the 1920's and coming over here "on the boat" and also that there was a relative who had "been in the kaiser's army, but I never really asked a whole lot about that, or how that period affected those groups to today)  …probably there isn't a good answer, and really, just can't imagine it.

Can't imagine it then, or now, with so many similar cases through time like others said, of a charismatic individual with enough intelligence and people skills (whether they are mentally sound, or not) to sway so many to their side.  If a small part of the bigger 'lie' this leader is telling sounds right to you (i.e. being patriotic or fitting in with a group that shares similar enough beliefs, or giving you a place to belong in an Us vs. Them solidarity), are humans so easily willing to overlook the 'this might be wrong' thought? 

Sigh… if they get that at all, considering every big thing we consider bad at one point had staunch supporters thinking it really was how things should be.  Reminding me of the slave trade, having just come off from watching 'Amazing Grace' - so many who didn't want it banned despite the morality of, for reasons considered perfectly viable of 'upholding the economy' or 'for keeping our country stronger than others'.  It does paint a discouraging picture contrasting how so often humans rally together for a better good, that it seems just as easy for many to decide as a group 'this practice is okay because I'm not the only one doing it, or because it's benefitting us somehow' even when it causes harm to others… it seems through history some people needed -some- group to pick on, and the fears/hatreds of the time would change which one that was?  The need to be for or against something/someone, or just plain weakness as an individual despite morals/education/etc?

Let me say one thing - once again I'm very, very proud of our board. The way this sensitive topic is discussed here is really amazing. There are so many true and intelligent things said by all of you.