why torture doesn't work

From time to time, this blog has discussed the morality of torture, which, for its proponents, hinges on one thing: whether it works. But even the severest utilitarian would have hard time justifying a practice that, as far as we can tell, is worse than useless. Consider the newly-released details of the CIA's investigation on Abu Zubaida. Ed Brayton points to the story, found in the Washington Post:

When CIA officials subjected their first high-value captive, Abu Zubaida, to waterboarding and other harsh interrogation methods, they were convinced that they had in their custody an al-Qaeda leader who knew details of operations yet to be unleashed, and they were facing increasing pressure from the White House to get those secrets out of him.

The methods succeeded in breaking him, and the stories he told of al-Qaeda terrorism plots sent CIA officers around the globe chasing leads.

In the end, though, not a single significant plot was foiled as a result of Abu Zubaida's tortured confessions, according to former senior government officials who closely followed the interrogations. Nearly all of the leads attained through the harsh measures quickly evaporated, while most of the useful information from Abu Zubaida -- chiefly names of al-Qaeda members and associates -- was obtained before waterboarding was introduced, they said.

Zubaida's "confessions" produced garbage, yet his captors, even when faced with evidence that further waterboarding was pointless, continued to torture him. Brayton comments,

This is one of the main problems with such interrogations and it has nothing to do with those famous "ticking timebomb" scenarios we hear so much about. They're convinced they have a high value target in detention but in fact he's just a low level flunkie who has little to tell [them]. So when he doesn't give them useful information, they're convinced they have to torture him to get the information they're sure he has.

And even after they torture him and he tells them everything he thinks they want to hear to make them stop, and even after they waste time and resources chasing all the false leads he gives them, they never think to question their own assumptions either for that person or for others. Even after the failure of their first instance of torture, they continued to approve others.

I see at least two reasons for this. First, in the heightened emotional state brought on by the combination of crisis-thinking and moral abnegation, the ordinary distortions of confirmation bias are amplified until the noise drowns out the signal. Second, torture is a sort of moral Rubicon--once crossed, there's no going back, no possible admission of failure, for it would reveal a truth too ugly to comprehend--not only to the outside world, but to the torturer.