From an article in New Scientist.
http://www.newscientist.com/article/...mg20327174.600
This follows a study comparing identical and fraternal twins, showing that the genetic as opposed to environmental influence on IQ increases with age.
I quote from the article :
"Plomin's team calculated that in childhood, genes account for about 41 per cent of the variation in intelligence (see graph). In adolescence, this rose to 55 per cent; by young adulthood, it was 66 per cent (Molecular Psychiatry, DOI: 10.1038/mp.2009.55)."
Interesting ....
Anyone care to speculate on why?