Sometimes what one hears at random leads to a whole train of thought. This happened on Sunday morning (first Sunday of 1997) when I heard comments on the radio on the book entitled “Why Michael couldn’t hit” [a baseball]. The explanation of this man’s affliction was that he never played baseball as a kid, and you cannot learn this skill later in life. There is a “window of opportunity” only in pre-teen years, and he had missed it. And this is also true of other skills, such as violin playing, and of course language. These can be learned at a mature age, but with much more difficulty.

The more detailed explanation is this: We are born with a large repertoire of possible sensori- motor skills, more than we will ever need and more than can be actually realized. Which ones we learn in real life is detennined by experience, i.e. by exposure to and practice of, those skills. The skills to which we are exposed become perfected, the ones to which exposure never occurs, atrophy. It is a selection process, conducive to the child being socialized appropriately to his/her own culture. A hunter’s child learns to hunt, an intellectual’s child learns to read, and so on. The child’s immense potentialities actually get cut down in the course of education.

Thus it is useless to argue whether our gifts and talents are inherited or acquired – for both are true. All talents are potentially genetically programmed, but only some are selected by education. Children, I noticed, are much quicker to learn how to use computers than are adults. But I am puzzled: how can computer skills be genetically pre-programmed before there were any computers? I suppose that what is genetically pre-programmed are certain sensori-motor skills, those of eye-to-hand coordination, for example, in operating a mouse or a joystick.

Piaget’s sensori-motor stage of a child’s cognitive development certainly deserves more attention than the later stages of concrete and fonnal operations, if this selection mechanism (which I call “pruning”) is true. For the later stages are poorer in repertoire than the earlier stages, although, of course, in the later stages there is much improvement in actual perfonnance of the skills selected.

How general is this pattern of pruning a vast reservoir of possibilities and perfecting only some of them? I could think of several instances of the same pattern.

1. T-cells of the immune system can initially “recognize” a vast variety of antigens, but they are “educated” (that word is actually used) in the thymus to recognize only non-self and not self. The “education” takes the drastic fonn of eliminating, by inducing apoptosis or cell suicide, those T-cells that recognize self (for they would cause auto-immune diseases). (Our school children who fail a grade are only made to repeat it, not executed. Thus Buddhist believers can try to learn the lesson in another lifetime, not go to hell like sinning Christians.)
2. In the fetal developing brain, many more neurons are fonned than are eventually needed. Each starts growing toward its assigned destination, but many get lost in the maze and never make it. They are eliminated by apoptosis and die.
3. According to Stephen 1. Gould’s “Wonderful Life”, there were many more different phyla (basic body plans) among early animals (invertebrates) in the Cambrian than in later evolution. Only a few made it through the multiple great extinction episodes, and not necessarily on their own merit (“fitness”). Contingency or luck played a great part. (See previous essay, “Contingency”.)
4. It is conjectured (no one can prove it) that there are many ways in which the brain can perceive external reality (cf. “Crack in the Cosmic Egg” in Section VI), but only one is selected as conducive to survival. “If the doors of perception were cleansed, we would see the world as it really is – infinite.” Yet philosophers tell us that we cannot perceive “things in themselves”, only pale reflections of them, as in Plato’s cave; and in decreased number of dimensions (from 3 to 2 in the shadows on the cave walls). The real world may have n dimensions, like phase space. Why should there be only 2 or 3?
5. In acquiring knowledge, we sometimes accumulate far more data than we can usefully comprehend. We then employ methods such as factor analysis to prune down the information to useful dimensions. This is called “data reduction”, and it is quite essential. We can comprehend only about 7 to 10 factors, not several hundred.

We and Nature sometimes “know” far more in the beginning than after a process of development or “education” has taken place. We are limited, and many mechanisms by which we live are limited, DELIBERATELY, (by whose decision?) in order to keep ourselves from being overwhelmed by information overload. Pruning mechanisms such as natural selection, sheer luck, apoptosis, forest fires, and the great extinctions keep things under control; otherwise they might run off to infinity, like some points in forming the Mandelbrot set. (The points that run off to infinity are in fact pruned off, not counted in the finished set.) Lack of pruning might lead to auto-immune diseases (in the case ofT-cells), to schizophrenia (in the case of perceiving multiple worlds), to unhealthy climax forests (if fires did not prune them). Life must be kept limited, or, like the tower of Babel, it would aspire to reach the Infinite God.