Friday, November 21, 2008

When feelings and thoughts collide

kw: book reviews, nonfiction, sociology, intelligence

In Hawaiian and classical Egyptian cultures, a king was required to marry his sister. It was unheard-of for either party of the couple to disagree. In contemporary Western culture, a highly distasteful act is said to be "like kissing your sister." There's the old proverb that "one man's meat is another man's poison", and it clearly refers to more than just foodstuffs. How are we to understand the visceral reactions people have to one or the other circumstance? I am sure old Pharaoh would be appalled at our attitude towards his marriage. Some moral choices really are culturally derived. Others less so. I won't say more than that, however.

On a milder note, the next time you watch a baseball game, pay attention to the way the fielders go after a high fly ball. Many times, one will simply trot over, almost unconcernedly, and catch the fly without breaking stride. Other times, one will run desperately for the back fence, only to watch the ball fly just overhead. How does the first player know where the ball will land, and how does the second know it is beyond catching?

It turns out that fielders in baseball take advantage of a principle of calculus that needs no calculation: If you gauge your running speed so that the angle to the ball remains constant, you'll get to the ball just when it comes within reach. There is a way to prove this with calculus, but we know the ball players aren't using any calculus, and very likely none of them know of the intersecting tangent principle anyway.

The first player sees, after the ball stops climbing, that it appears to be drifting in one direction. He trots or runs until the drift apparently stops. Then he knows he can catch the ball. The second player sees that, no matter how fast he goes, the ball's angle keeps getting ahead of him. He hopes he'll be able to jump for it at the wall. The faster that angle is changing, the less chance he has.

Nobody taught this to the players. They learned it by experience. They don't think about it. If you ask one, they usually can't say what they are doing. They "just know" how fast to run to intercept the ball. They don't have to know where the ball is going to land. They just know, if they keep the angle constant, the ball itself will lead them to its landing point…if they think about it at all.

Life is full of heuristics like this. Without them we could hardly function. We seem to be hardwired for grammar, for example. How else to explain that we all use grammar with a measure of correctness (regional and dialect differences aside) that no machine can match, but very few of us could explain the "rules" of the grammar we use with such near-perfection all day long.

Psychologist Gerd Gigerenzer has written Gut Feelings: The Intelligence of the Unconscious, in which he pries into a number of these heuristics. The book rewards careful reading (which is why this post is a couple days late). He investigates many of the choices we make, and how they are made. Consider the Chain Store Paradox.
You own a chain of widget shops. A competitor plans to open similar shops, one by one, in all the areas in which your shops are found. How do you respond?
A logical process called backward chaining reasons thus:
I have twenty shops. If the competitor sets up nineteen shops, then it makes little difference if a twentieth is set up, so I ought to share the trade. By the same token, the difference between the eighteenth and nineteenth shops is similarly negligible. And so on, to the first shop. Therefore it makes little sense to engage in a price war.
However, is this what happens? No, you would most likely try, with the first opening, to drive it back out of existence, even selling your widgets at a loss for a time. The simpler evaluation is, "Every competitive shop will cut into my business, so I need to protect my business." Period.

The message of this book? Simple evaluations often outperform more complex ones. For example, suppose you are asked, which is the larger city, Omaha or Philadelphia? How many people know that Philadelphia is four times as large as Omaha? "Only four?" some may ask. Why? Because we hear of Philadelphia so much the more. To most people, Omaha is where "Prudential of Omaha" is from, and that's about it. Go overseas, and you'd be hard-pressed to find people who've heard of both cities; most know Philadephia, very few know Omaha. And the heuristic does work out, that the more well-known a city is, the larger it tends to be.

If you give people a test, to tell among twenty pairs of city names, which is largest, those who recognize about half the names do the best. Those who don't recognize any of the names just guess. They don't have any knowledge to help them. Those who are very familiar with geography and know nearly all the names, but few details, also do badly, because the "recognition heuristic" doesn't help them. But when you know only about half the cities on a list, it is likely that most of the ones you know are larger than the ones you don't know. This turns out to be true about 80% of the time.

Have you ever flipped a coin to decide between two seemingly identical choices, only to find you "didn't like" the coin's result? The coin forced your unconscious intelligence to assert itself. Our mind is able to make sense of incomplete data. It excels at that. This is where our hunches come from. As the author shows, many of our hunches are smarter than more complex ways of deciding. And that is a good thing, because doctors are so pressed for time, they have to diagnose your condition based on rather vague clues; some of us are still living because many of them get quite good at such "hunch" diagnoses. When this or that guru recommends, "Trust your gut", it is often good advice.

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