Whatever the facts of the crimes in this week's pair of institutional scandals (and it bears saying that trials in the Afghanistan "kill team" case are ongoing, while Jerry Sandusky hasn't yet been convicted of anything), the facts about the institutional responses by the Army and Penn State are not in dispute. And they're yet another reminder that, as Frank Bruni remarked the other day, institutions are bad at policing themselves. Which is putting it very mildly: So… you're pretty sure you see one of your superiors sodomizing a 10-year-old and you … go home and call your Dad? You get a phone call saying soldiers are killing people for sport and you … say there's nothing you can do? Say what, now? We outsiders are astounded, and we can only ask: How could it come to this? Why aren't institutions good at policing themselves?

Perhaps, though, that's the wrong question. It's premised on a rationalist model of moral behavior, which holds that an evil act must evoke the same response in all people at all times. Because child abuse and the murder of innocents are horrible, we're shocked that an Army sergeant shrugged off a phone call about the "kill team" from the father of a troubled soldier. We're amazed that Penn State's collective response to a report that Sandusky raped a boy on its property was to tell Sandusky to stop bringing boys to campus.

It shocks the conscience, when you think about it in the abstract. But of course no one lives through these cases in the abstract, and there is no such thing as "the" conscience. There are only individual consciences, embedded in individual minds, and those minds are bound together into collective entities like families, nations, religions, football fan groups and countless other tribal-feeling forms of affiliation. And when minds are so bound into collectives, the bonds have powerful effects.

Specifically, it is immensely difficult to think ill of someone who brings glory and honor to your group. This is, of course, monumentally unfair: If you think Steve Jobs was a bully and a crank, it should not make any difference that he brought forth so many beautiful products that made you an Apple guy. But it does. Would students at Penn State have rioted for Joe Paterno if he just happened to be just some 84-year-old neighbor who failed to investigate what he'd heard about Sandusky? Would Calvin Gibbs, this week convicted of organizing the murder-for-the-hell-of-it of harmless Afghan civilians, have had much influence over his comrades if he hadn't been good at his job ?("What you want a soldier to look like, act like, speak like," one of them told Luke Mogelson. "He’s like the epitome of soldier.")

It's also difficult, once you've developed loyalty to an institution, group or profession, to ignore its needs. French has a useful term for the effects of often-emotional, often-rigorous training: deformation professionelle. It refers to the difference between the way you or I might see a bloody wound and the way it would look to a doctor, or a soldier, or war reporter. Part of that difference is desirable (who needs a doctor who freaks out at the sight of a broken shin?) But part is undesirable, a kind of unfortunate corollary: The tendency to excuse, explain away and defend; the tendency not to see at all.