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No. 1798:
Mind Reading

Hershey hidden in couch cushions Today, let us be mind readers. The University of Houston's College of Engineering presents this series about the machines that make our civilization run, and the people whose ingenuity created them.

Science writer Carl Zimmer poses the following situation: Billy stops by the store to buy a candy bar on the way home from school. At home, he settles down on the couch to eat the candy while he watches TV. Then his mother comes in to say he must first go out and rake the leaves. Billy stashes the candy behind a couch pillow and goes out to do his chore.

Then his sister comes in to watch TV. She moves the couch pillow and finds the candy bar. She grabs it and hides it in the bookcase so she can eat it when the coast is clear. Billy finally finishes his work and returns to his long-awaited chocolate bar.

Now, Zimmer asks, "Where will Billy look for it?"

That sounds like a trick question, but it's not. Of course, he'll look behind the couch pillow. But, Zimmer points out, if you describe this situation to a very young child, you'll get the answer, "In the bookcase." That's obviously where the candy is.

The point is that you and I have developed a remarkable ability: We don't follow the candy; we follow Billy's mind. We read his mind. As psychologists put it, we form a theory of the mind. Chimpanzees and other animals do remarkable things; but as yet it seems that the only creatures who can read intentions are we humans.

Hershey hidden in bookcaseAs biologists study parts of the brain where we process our readings of intention, they find that the evolution of language also requires that ability. To understand language, says one psychologist, we must know what people intend when they refer to things.

The condition of autism arises when those special portions of the brain don't function properly. The root difficulty faced by an autistic person is difficulty in reading the intentions of others.

Mind-reading, in this sense, is a glorious gift -- one that some people hone to an exquisite edge. The public entertainer whom I find most loathsome is one, blessed with this gift, who claims to transmit messages from the spirit world to audience members. That person displays an extraordinary ability to grasp what someone is thinking from very fragmentary evidence.

So, if this gift is magnificent, it can also be so easily misused. I tried the question of Billy and his candy bar on a colleague. He said it reminded him of a primary meaning of the word innocent, and that is not-knowing. An innocent is one who has yet to be corrupted by knowledge. No wonder a small child will misread Billy's search for the candy bar.

So, we'll keep trying to read each other's intentions. But another psychologist points out that, for centuries, we've believed self-awareness to be what separates us from animals. Now the ability to read intentions appears to be the unique human attribute. Put that ability into the hands of people who haven't developed the quality of self-reflection, and, perhaps, that is where we humans stand in the greatest danger of behaving badly.

I'm John Lienhard, at the University of Houston, where we're interested in the way inventive minds work.

(Theme music)

C. Zimmer, How the Mind Reads Other Minds. Science, Vol. 300, 16 May, 2003, pp. 1079-1080.

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