If you bop on over to the Stanford University Distinguished Lectures series your will find this address by Philip Zimbardo: The Psychology of Evil - a cheery topic. 

Dr. James Benjamin gives a summary noting the focus here is not on leaders, such as Hitler, Pol Pot, and other despots but rather on what would motivate the followers to go along.  "In the process, Zimbardo describes the findings of several powerful social psychology experiments, such as Stanley Milgram's obedience experiments, Zimbardo's own experiments on deindividuation (as well as the infamous Stanford Prison Experiment), and Albert Bandura's work on dehumanization."  

Okay. 

Here's what he sees at the "take home" message:

Start with an ideology (justifying beliefs for actions). 

Use authority to legitimate that ideology. 

Give people desirable roles to play with meaningful status. 

Have rules that channel behavioral options. 

Employ semantic distortion to disguise truth (help = hurt). 

Arrange for contractual agreement with the game rules before the game begins. 

Make situation give permission to engage in usually taboo acts. 

Make initial harmful act minimal, minor, trivial. 

Enable subsequent acts to escalate only gradually, minimally, but their cumulative impact can be deadly. 

Displace responsibility for consequences on authority or others. 

Get actors involved in action, in technology, in details, without time to think through the meaning of their actions. 

Don't allow usual forms of dissent to work; undercut them so dissent does not lead to disobedience. 

Put actors in novel setting, without familiar referents. 

Have authority transform gradually from just to unjust. 

Give no training in how to challenge unjust authority. 

Do not provide apparent means for exiting the situation. 
From Zimbardo's research on deindividuation, we can draw these conclusions:

Take away people's sense of uniqueness and individuality, because that encourages spontaneity, rebelliousness, and independence. 

Do so by submerging them in groups. 

Put them in uniforms. 

Disguise them with hoods or masks. 

Feel better now? 

And the usual - dehumanizing the intended victims makes it considerably "easier to aggress against them." 

As Benjamin points out, it seems evil is facilitated by a number of factors that psychologically inoculate the individual actor from coming face to face with the consequences of his or her actions.  "The not so comforting take home message is that any of us has the capacity, given the right set of conditions, to engage in evil behaviors; and collectively as a society we could commit terrible atrocities under the right set of conditions.  When people have in the past tried to reassure me that a Hitler-esque or Stalin-esque sort of environment could never happen here in the US, I find myself returning to the work of Milgram, Zimbardo, and Bandura (among others) and wonder how one could be so sanguine."

Ah, he worries too much. 

And he also recommends this paper by Zimbardo: A Situationist Perspective on the Psychology of Evil: Understanding How Good People Are Transformed Into Perpetrators. (PDF format). 

Do you doubt Bush will be reelected? 

__

Reading this my "news guy" friend from Atlanta sent this:

As far back as maybe 1969, when I worked at NBC, I helped produce a segment for their "First Tuesday" magazine show called "The Zimbardo Tapes," about Zimbardo running this psychological experiment in which Stanford student volunteers were randomly assigned roles as prisoner or prison guard, and were videotaped.   On the tapes, we saw the "guards" become progressively more sadistic in their treatment of the "prisoners," one of the latter screaming that this was only an experiment, but nobody seemed to be listening. I think they had to close down the experiment early because it was getting way out of hand.

Yep, I remember that.

And my friend from Albany wrote to say - " ... really important information in this.  Long, but I'm going to try and get my daughter to read it."

Maybe we all won't drink the Kool-Aid.