Should national security depend on Michael Chertoff's gut?

"Gut Feelings" author Gerd Gigerenzer talks about the Bush administration's hunches, how to make good decisions and why you should listen to your doctor.

By Farhad Manjoo

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July 30, 2007 | Early in July, Michael Chertoff, the secretary of the Department of Homeland Security, told the Chicago Tribune that though he had no specific information pointing to a new threat, his "gut feeling" suggested that the U.S. faced a heightened risk of a terrorist attack during the next couple of months. Summertime is an "appealing" time of year to the enemy, Chertoff said; it was natural to assume, then, that the season would once again bring "increased vulnerability."

Chertoff's intestinal sixth sense was met, to put it mildly, with some skepticism. The Bush administration has not proved to be above pulling the trick of conveniently timed terror warnings; now, facing congressional rebuke on matters from Iraq to everything else, the White House obviously was once again aiming to distract us.

But what rankled folks wasn't that administration officials were once again milking the terror-threat cow -- it was how lamely they were doing it. Chertoff's gut! The comment smacked of self-parody, a takeoff on Stephen Colbert's line that we are a nation divided "between those who think with their head and those who know with their heart." MSNBC anchor Keith Olbermann called Chertoff "a hunch-driven clown," and advised that he turn his duties over to someone who "represents the brain and not the gut, certainly to somebody who does not, as you do now, represent that other part of the anatomy -- the one through which the body disposes of what the stomach doesn't want."

The controversy hit at a propitious moment for Gerd Gigerenzer, a German behavioral scientist who has made human intuition his life's work. Gigerenzer's new book, "Gut Feelings: The Intelligence of the Unconscious" -- a more deeply scientific (if less tickling) look at a subject first popularized by Malcolm Gladwell in "Blink" -- seeks to undo the cultural dismissal of the gut.

Not just Chertoff's but everyone's: Intuition, Gigerenzer writes, "is more than impulse and caprice; it has its own rationale." A "gut feeling" is not a supernatural force -- it's not ESP. Rather it is the product of your brain quickly, often unconsciously, using a rule of thumb (what academics call a "heuristic") to arrive at a decision using little evidence.

Imagine that you're playing baseball and a fly ball comes headed your way. How do you know where it's going to land? As Gigerenzer points out, people do not -- as scientists have long assumed -- calculate the ball's trajectory, estimating its velocity, angle, spin, the air's resistance and wind speed. Indeed, in experiments, baseball players have proved very bad at guessing where a fly ball will hit the ground. Instead, everyone who has ever caught a ball has (unconsciously) used a rule of thumb to do so. The rule is known as the "gaze heuristic," and it governs your speed as you chase the ball: You fix your eyes on the ball, start running, and adjust your speed so that the angle between you and the ball remains constant. In other words, instead of computing the ball's trajectory, all you have to do is keep your eye on it -- "the heuristic leads the player to the landing point," Gigerenzer writes.

Gigerenzer says that these heuristics arise out of our "evolved capacities." We've evolved to be able to track objects through the air, for instance. Consequently, our gut feelings -- whether they're useful in catching a ball, or in predicting a terrorist attack -- aren't to be taken lightly. Intuition is not a deviation from the right way to make decisions; it's how we make decisions all the time.

I spoke to Gigerenzer on the phone; he lives in Berlin.

Let me start by asking you about Michael Chertoff's gut. Should we care if a public official says he has a gut feeling about something? Should we place much stock in that?

It depends on whether your public official is an expert. There are many American politicians who say that they rely on their gut feelings -- including your president, who said, "I'm a gut player." On the other hand, we know that some people are real experts, and we can trust their gut feelings to a good degree, particularly if you are an expert in a situation where you have feedback and you can learn from it. But it's less clear if one can learn from terrorist attacks. There are not so many of them, at least on American soil.

So because there's no practice in this field a gut feeling is probably shaky?

It might be much shakier, right. But this also shows that much of intelligence work is based on guesswork and gut feelings. I have given a lecture recently to a group of international security services from many countries, and it's very clear that although they work with the most expensive computers and try to feed in all the information they have, these computers often do not do much better than a good expert's gut. Intelligence typically has lots of evidence, but how reliable is it? How do you weigh it? If you sit on a mountain of evidence, at the end you have to make a decision based on your gut.

Well, but that still doesn't resolve the question -- when a politician says he goes on his gut feeling, we really have no way of knowing whether he's an expert. So what do we do?

That's right. I would look at his record. Let him make some more predictions with his gut and we can find out how good he is. If he has a good record, then I think it's reasonable to trust his gut feeling.

Next page: Ignoring information can pay off