7- blink
In front of you are four decks of cards—two of them red and the other two blue. Each card in those four decks either adds points to your score or subtracts them, and your job is to turn over cards from any of the decks, one at a time, in such a way that maximizes your score. What you don't know at the beginning, however, is that the red decks are a minefield. The rewards are high, but when you lose on the red cards, you lose a lot of points. Actually, you can win by only taking cards from the blue decks, which offer a nice steady diet of 50-point rewards and modest penalties. The question is, how long will it take you to figure this out?
Scientists at the University of Iowa did this experiment a few years ago. They found that after we've turned over about fifty cards, most of us start to develop a hunch about what's going on. After about eighty cards, most of us have figured out the game and can explain exactly why the two red decks are such a bad idea. That much is straightforward. We have some experiences. We think them through. We develop a hypothesis. We deduce A from B. That's the way learning works.
But the Iowa scientists did something else. They hooked each player up to a machine that measured the activity of the sweat glands below the skin in the palms of their hands. Like most of our sweat glands, those in our palms respond to stress as well as temperature. The Iowa scientists found that the players started generating stress responses to the red decks by the tenth card, forty cards before they were able to say that they had a hunch about what was wrong with those two decks. More importantly, right around the time their palms started sweating, their behavior began to change as well. They started favoring the blue cards and taking fewer and fewer cards from the red decks.
The Iowa experiment implies that our brain uses two very different strategies to make sense of the situation. The first is the one we're most familiar with. It's the conscious strategy. We think about what we've learned, and eventually we come up with an answer. But it takes us eighty cards to get there. It's slow, and it needs a lot of information. There's a second strategy, though. It operates a lot more quickly. It starts to work after ten cards, and it's really smart, because it picks up the problem with the red decks almost immediately. It has the drawback, however, that it operates—at least at first— entirely below the surface of consciousness. It sends its messages through weirdly indirect channels, such as the sweat glands in the palms of our hands. It's a system in which our brain reaches conclusions without immediately telling us that it's reaching conclusions.
The part of our brain that leaps to conclusions like this is called the adaptive unconscious, and the study of this kind of decision-making is one of the most important new fields in psychology. The adaptive unconscious can be thought of as a kind of giant computer that quickly and quietly processes a lot of the data we need in order to keep functioning as human beings. When you walk out into the street and suddenly realize that a truck is bearing down on you, do you have time to think through all your options? Of course not. The only way that human beings could ever have survived as a species for as long as we have is that we've developed another kind of decision-making apparatus that's capable of making very quick judgments based on very little information.
The psychologist Timothy D. Wilson in his book Strangers to Ourselves says that we toggle back and forth between our conscious and unconscious modes of thinking, depending on the situation. A decision to invite a coworker over for dinner is conscious. You think it over. You decide it will be fun. You ask him or her. The spontaneous decision to argue with that same coworker is made unconsciously—by a different part of the brain and motivated by a different part of your personality.
Whenever we meet someone for the first time, whenever we interview someone for a job, whenever we react to a new idea, whenever we're faced with making a decision quickly, we use that second part of our brain. How long, for example, did it take you, when you were in college, to decide how good a teacher your professor was? A class? Two classes? A semester? The psychologist Nalini Ambady gave students three ten-second videotapes of a teacher—with the sound turned off—and found they had no difficulty at all coming up with a rating of the teacher's effectiveness. When Ambady cut the clips back to five seconds, and even two seconds, the ratings were essentially the same. A person watching a silent two-second video clip of a teacher he or she has never met will reach conclusions similar to those of a student who has sat in the teacher's class for an entire semester. That's the power of our adaptive unconscious.
I think we are innately suspicious of this kind of rapid cognition. We assume that the quality of a decision is directly related to the time and effort that went into making it. When doctors face a difficult diagnosis, they order more tests, and when we are uncertain about what we hear, we ask for a second opinion. And what do we tell our children? Haste makes waste. Look before you leap. Stop and think. Don't judge a book by its cover. We believe that we are always better off gathering as much information as possible and spending as much time as possible in deliberation. We really only trust conscious decision-making. But there are moments, particularly in times of stress, when haste does not make waste, when our snap judgments and first impressions can offer a much better means of making sense of the world. Decisions made very quickly can be every bit as good as decisions made cautiously and deliberately.
