Why do we scratch our heads when we're thinking?

Dear Matthew Alice:

Why do people scratch their heads when they are trying to think of an answer? Does it work?

M.S., San Diego

The perfect M.A. question, of course. The elves apply digits to dome many times a day, although Grandma Alice believes it's mostly a nasty dandruff epidemic. And considering the answers they came up with, I think I have to agree with her. We're left at the mercy of neuropsychologists and other forms of head shrinkers, so an absolute, unarguable answer probably isn't possible. But let's try this one on for size.

Automatic gestures like head scratching are a kind of expressive shorthand for our feelings. One popular explanation for any hand-to-head movements is that they're frustrated aggression-- a reversion to the natural movements of our rock-throwing ancestors. If you watch a small child strike at something, he'll raise an arm over his head and bring it forward in an arc. It's a natural, unstudied movement. Not much finesse, but for a cave man it got the job done.

When we're wrestling with some knotty problem, we experience feelings of frustration, perhaps some anger, and before we know it, our hand flies up in the air. But hold it. In these modern times, it's not polite to bash the guy who asked the question. So instead we deflect attention from the movement and scratch or rub our head or chin or neck. At lest that's the way anthropologists see the situation.

Psychologists will tell you that most absent-minded self-touching movements are efforts to comfort ourselves in times of stress. It's like giving ourselves a reassuring pat. Head scratching would be a way of relieving the stress of not knowing something, and it's directed at our heads because that's the source of our distress.

Don't like those explanations? Well, we got a million of em. Neuropsychologists might say that head scratchers are people who learn best by touch or movement. Each person has a dominant learning mode, they claim-- visual, auditory, or sensory. A visual person might cast their eyes heavenward while pondering. An aural person might tug on an ear.

Personally, I think we put hand to head to try to knock the right answer into the proper brain slot. But whaddo I know. And does head scratching work? Um, well, gee...let me get back to you on that one.