The Persistent Provocativeness of the Banality of Evil

I was only vaguely familiar with the infamous Stanford Prison Experiment until I came across some details in this article. Philip G. Zimbaro, the psychologist who conducted the experiment, recalls:

"By the end of the first day, nothing much was happening. But on the second day, there was a prisoner rebellion. The guards came to me: 'What do we do?'

"'It’s your prison,' I said, warning them against physical violence. The guards then quickly moved to psychological punishment, though there was physical abuse, too.

"In the ensuing days, the guards became ever more sadistic, denying the prisoners food, water and sleep, shooting them with fire-extinguisher spray, throwing their blankets into dirt, stripping them naked and dragging rebels across the yard.

"How bad did it get? The guards ordered the prisoners to simulate sodomy. Why? Because the guards were bored. Boredom is a powerful motive for evil. I have no idea how much worse things might have gotten."

Shit. Zimbardo goes on to parallel the experiment's situational drivers of abuse to those behind the torture in Abu Ghraib. Undoubtedly there are basic (banal) parallels. But what strikes me is how rapidly and intensely the experimental abuse escalated, given the situation (an experiment) and the players (of 70 male respondents, the 24 deemed most psychologically stable). It's one thing for low-ranking soldiers to get carried away over the course of overseeing suspected enemy combatants in a foreign prison. The grunts were in an unpleasant environment doing an unpleasant job for who knows how long, and they were not exactly the most reasonable bunch; racism, religion, revenge, and the like were among their motivations. This is not to excuse the atrocities they committed, just to put them in perspective. The experimental participants were presumably very different people in a very different setting, and it's harder for me to wrap my mind around what they did. I guess that's what's so unsettling about these experiments: everyone thinks "but I'd never do that," and then they do (they would; I wouldn't). Or is there more to Zimbardo's story? I'm curious what the participants were like. I was initially under the impression that they were students, which naturally blew my mind even more.

UPDATE: the participants were indeed mostly college (or college-bound) students according to this short documentary.