Brainy Kids' Brains Grow Slowly
That's the news from Nature, the scientific journal, in a new study out today. The cortex of all children's brains thickens as they get older, and then thins during the adolescent years. The cortexes (I'm stumped on the plural) of children with IQs of 121-149 thicken more slowly than those of children with average intelligence, reaching peak thickness at age 11, instead of age 6. Nature requires a subscription, but you can read an AP article about the research here.
No one knows quite what the implications of this are. One of the study authors suggested that a slower-thickening cortex could promote high intelligence, because the child is experiencing more complex things as his brain is growing. By this theory, gifted children would get a longer learning time than others; they'd still be learning rapidly into the late childhood years, where as other children would end that stage around age 6. But I'm not sure if that works, logically. Highly gifted children show their giftedness from infancy. They don't just outpace other children after age 6. Perhaps bright children seek out more stimulation, and this somehow slows the thickening of their cerebral cortexes (Again, what is the plural?).
Regardless, the research shows that there is a physical difference between children with gifted-level IQs and children of average intelligence. IQ tests get a bad rap, and certainly they can't show what a child will accomplish in life. Maybe they can be coached, and environment certainly plays a role. But these physical differences indicate that the tests are on to something, whatever that is.