The older we get, the more our IQ is down to genes

Heritability of IQ rises with age, according to research shared by a behavioural-genetics commentator. The influence of the shared family environment dwindles as people get older. The finding runs against the intuition that childhood upbringing leaves an ever-deeper mark. Instead, the common home seems to fade from the picture, and genetic differences account for more of the gap between individuals. It is a counterintuitive result: people grow more like their genes, not their upbringing, as the years pass.