Why don't you 
Recently, I’ve been giving some thought to the capabilities of the human mind and the meaning of intelligence. The common perception is that human intelligence grows as we age, that young children start off stupid and it is adults’ job, through the various institutions of education, to implant the right “knowledge” into children’s brains until they’re intelligent like us. I think that’s very, very far from the truth.
If you’ve read Dr. Robert Epstein’s “The Case Against Adolescence,” you may remember, in his chapter on intelligence, his description of two studies conducted in the 1940s, one by David Wechsler and one by J. C. Raven, demonstrating that “intelligence,” to the extent that it is measured by one’s capacity to score highly on an IQ test, peaks in the early- to mid-teens. Our IQ remains relatively constant throughout our lives, because IQ is a measure of how well we scored on the test compared to everyone else the same age as us. But, according to Wechsler and Raven, raw scores on “intelligence tests” rise rapidly during childhood, peak between the ages of 13 and 16, and decline steadily thereafter.
But raw scores on IQ tests do not measure intelligence. They measure how closely our “mental model of reality,” as educator John Holt puts it, conforms to actual reality, or at least societally perceived reality. Some portions of intelligence tests measure social knowledge; others measure the capacity to perform mathematical calculations mentally; others measure one aspect of memory or another, or our ability to put things in sequence.
But this is not real intelligence. Real intelligence is our ability to construct our mental model of reality from the ground up, to absorb information from the world around us, the individual bits of which may not make any sense by themselves, and to detect patterns in it, to analyze it, to fit the bits and pieces into a coherent whole and use them to further our understanding of the world. Not nearly as easy a task as writing symbols beneath their corresponding numerals as quickly as possible, one of the tasks of many IQ tests.
According to Wechsler and Raven, intelligence peaks in our teens. But I think that real intelligence peaks much earlier. In fact, I think it peaks between the ages of 1 and 3. Certainly, after the age of 5, when children generally enter school, real intelligence declines sharply, and continues to decline throughout life, or at least never increases.
