A number of articles about the Abu Ghbraib prison scandal (like this one) have mentioned a famous and frightening incident in psychological research…the prison experiment helmed by Dr. Philip Zimbardo in 1971. You can learn all about it over at Dr. Zimbardo's website but for those who don't want to make the trek: Two teams of apparently ordinary college students were selected. A mock prison situation was set up with one team functioning as guards and the other filling the role of prisoners. Within a very short time, the "guards" became inexplicably brutal to the "prisoners" who felt so put upon that they began plotting rebellion. It all got so ugly that Dr. Zimbardo was forced to terminate the experiment prematurely.
In the early eighties, a TV show I was working on did a story on the experiment and I got to meet and interview Dr. Zimbardo and view all the existing film and photos. The doctor still seemed shaken by the whole story but he was also puzzled that it had had so little impact on the policies and perceptions of actual prisons. Psychologists, he said, had devoted thousands of hours to discussing what it had all meant but the reaction of those involved with real incarceration was along the lines of, "Yeah, so?" It did not seem to matter to most that prisons might make criminals even more anti-social and psychotic…or that even the guards came out less human than when they went in. Soon after, when this country experienced an uncommon level of prison riots, it still did not seem to matter.
There does seem to be a parallel between Dr. Zimbardo's faux guards turning savage and the reportedly-undertrained military guards abusing Iraqi prisoners but I doubt it will be explored. During a war, there's never time to pause and ask why people act the way they do. And when we're not at war, we don't like to think about it.