After viewing photographs of abuse of Iraqi prisoners, Colorado Senator Ben Nighthorse Campbell said, "I don't know how the hell these people got into our army."

While I appreciate Senator Campbell's outrage, I worry about an assumption that I see underlying his statement, the assumption that these were bad people before they got into our army. If we attribute the abuse of Iraqi prisoners primarily to the character of "these people," we will fail to prevent future abuses.

In 1971, Phil Zimbardo ran an experiment, now infamous, at Stanford University. He recruited 24 psychologically healthy men, divided them randomly into "guards" and "prisoners," and placed them in a simulated prison environment.

Zimbardo's intention was to observe for 10 days, but long before the 10 days were up, the experiment went horribly wrong. The guards began treating the prisoners in brutal ways, including "stripping them, hooding them and ultimately forcing them to simulate sodomizing one another." Zimbardo himself got caught up in the action, not by partaking in it personally, but by seeing it only as psychologically fascinating.

On the sixth day of the experiment, Zimbardo's girlfriend Christina Maslach visited the mock prison. She was horrified at what she saw, both in the experiment itself and in Zimbardo's fascination. She angrily confronted him, tearfully shouting "What you are doing to those boys is a terrible thing!" Only then did Zimbardo recognize the meaning of what was happening and terminate the experiment.

The key lesson from this experiment is that social situations can induce even good people to act in horrible ways. Zimbardo advocates against attributing horrible acts entirely to the bad character of the perpetrators. He suggests that we instead take a "situationist approach" to understanding "unthinkable" behaviors:

The situationist approach should, in my view, encourage us all to share a profound sense of personal humility when trying to understand "unthinkable," "unimaginable," "senseless" acts of evil. Instead of immediately embracing the moral high ground that distances us good folks from those bad ones, and gives short shrift to analyses of causal factors in that situation, the situational approach gives all others the benefit of "attributional charity" in knowing that any deed, for good or evil, that any human being has ever done, you and I could also do — given the same situational forces. If so, it becomes imperative to constrain our immediate moral outrage that seeks vengeance against wrong doers; instead to uncover the causal factors that could have led them in that aberrant direction.

(There is much more information about this experiment and its lessons on the Stanford Prison Experiment web page, especially the related links page, which includes many articles about how the experiment parallels what happened in Iraq.)

The American MPs did horrible things. My intention in describing the situationist approach is not to excuse that. My hope is that we can prevent future abuses like the ones committed by the American MPs. The situationist approach suggests that attributing the abuses primarily to the character of the MPs will not prevent this from happening again.

If we are to prevent future abuses, we must remain keenly aware of the kinds of social forces that can induce good people to commit abusive acts. We must train prison personnel to be aware of those social forces, to watch for them, and to introduce compensating forces into the social situation to counteract the ones that nudge people toward these horrible acts.

I suspect that Senator Campbell was reacting in the heat of the moment, out of disgust and outrage at the photographs and videos he'd seen moments before. I understand his outrage. I feel it, too. I hope that even in our outrage we can find the presence of mind to heed the deeper lessons.