Originally Posted by Val
There is presumably some sort of brain development that has to occur.

That's a really interesting point--it makes me wonder whether it might be the case that kids who read early basically have skewed brain development that puts the emphasis on different areas than other kids in the early stages--and then perhaps increases the possibility of delayed brain development in other areas, causing an increase in 2e-ness?? Almost like a micro-example of the changes in brain development during evolution (you know, something like they're talking about here).

http://scienceblogs.com/notrocketsc...-delayed-genes-separate-human-brains-fr/

But maybe somebody like Simon Baron-Cohen has already written about something like that already, and I'd love to see it.