The NY Times Magazine described an interesting study that I’d never heard about before:
A study of French youngsters adopted between the ages of 4 and 6 shows the continuing interplay of nature and nurture. Those children had little going for them. Their I.Q.’s averaged 77, putting them near retardation. Most were abused or neglected as infants, then shunted from one foster home or institution to the next.
Nine years later, they retook the I.Q. tests, and contrary to the conventional belief that I.Q. is essentially stable, all of them did better. The amount they improved was directly related to the adopting family’s status. Children adopted by farmers and laborers had average I.Q. scores of 85.5; those placed with middle-class families had average scores of 92. The average I.Q. scores of youngsters placed in well-to-do homes climbed more than 20 points, to 98 — a jump from borderline retardation to a whisker below average. That is a huge difference — a person with an I.Q. of 77 couldn’t explain the rules of baseball, while an individual with a 98 I.Q. could actually manage a baseball team — and it can only be explained by pointing to variations in family circumstances.
That’s some amazing data. Either the IQ test is deeply flawed, or intelligence is less innate than we assumed (or, to put it more accurately, our genetic nature depends upon how we are nurtured). I hope this study encourages potential couples (especially rich couples) to contemplate adoption. Thanks to plasticity, our brain is never beyond redemption.
P.S. If I were a neuroeconomist, I would definitely want to know why rich parents tend to have kids with higher IQ scores. Is it more toys? Better schools? Less stress? Of course, trying to pick apart the mess of variables that we call childhood is a difficult task, but it’s certainly a question worth asking…