It seems that the progress of brains may be behind the intelligence of the kids. The growth and "flexibility" in the way the brains develop and change over the years may have something to do with higher IQs or otherwise – as the new research shows.
The general pattern of maturation, they report in Nature today, is that the cortex grows thicker as the child ages and then thins out. The cause of the changes is unknown, because the imaging process cannot see down to the level of individual neurons.
But basically the brain seems to be rewiring itself as it matures, with the thinning of the cortex reflecting a pruning of redundant connections….
One interpretation, (National Institute of Mental Health scientist Judith) Rapoport said, is that the brains of highly intelligent children are more plastic or changeable, swinging through a higher trajectory of cortical thickening and thinning than occurs in average children. The scans show the "sculpturing or fine tuning of parts of the cortex which support higher level thought, and maybe this is happening more efficiently in the most intelligent children," (researcher Philip) Shaw said..
I.Q. scores and measuring intelligence have long been controversial. Brain-imaging studies by Dr. Thompson and the study group have advanced the field by identifying physical features of the brain that correlate with I.Q.