There has been much said in the past few years about how emotions and reasoning are quite inseparable. Antonio Damasio and colleagues did a unique study published in 1994 using the Iowa Gambling Task. Here is Wikipedia’s explanation of the task:

The Iowa gambling task is a psychological task thought to simulate real-life decision making. It was introduced by Bechara, Damasio, Tranel and Anderson (1994), then researchers at the University of Iowa. It has been brought to popular attention by Antonio Damasio, proponent of the Somatic markers hypothesis and author of Descartes’ Error. The task is sometimes known as Bechara’s Gambling Task, and is widely used in research of cognition and emotion.

Participants are presented with 4 virtual decks of cards on a computer screen. They are told that each time they choose a card they will win some game money. Every so often, however, choosing a card causes them to lose some money. The goal of the game is to win as much money as possible. Every card drawn will earn the participant a reward ($100 for Decks A and B; $50 for Decks C and D). Occasionally, a card will also have a penalty (A and B have a total penalty of $1250 for every ten cards; C and D have a total penalty of $250 for every ten cards). Thus, A and B are “bad decks”, and C and D are “good decks”, because Decks A or B will lead to losses over the long run, and Decks C or D will lead to gains. Deck A differs from B and Deck C differs from D in the number of trials over which the losses are distributed: A and C have five smaller loss cards for every ten cards; B and D have one larger loss card for every ten cards.

Most healthy participants sample cards from each deck, and after about 40 or 50 selections are fairly good at sticking to the good decks. Patients with orbitofrontal cortex (OFC) dysfunction, however, continue to perseverate with the bad decks, sometimes even though they know that they are losing money overall. Concurrent measurement of galvanic skin response shows that healthy participants show a “stress” reaction to hovering over the bad decks after only 10 trials, long before conscious sensation that the decks are bad. By contrast, patients with OFC dysfunction never develop this physiological reaction to impending punishment.

Damasio, in his book, Descartes’ Error, discusses how we need this emotional feedback in order to make good decisions. People with OFC dysfunction do not register this feedback and thus have problems with the Iowa Gambling task.

Gerd Gigerenzer was interviewed in to discuss his new book Gut Feelings: The Intelligence of the Unconscious and how it relates to Michael Chertoff’s recent announcement that he had a gut feeling that terrorists would attack soon. Below is an excerpt:

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.