One thing that might muddle things and lead to this observation is that at a certain age, kids don't want to read much past their maturity level. This has been discussed here--what 9yo really wants to read for pleasuure at 1200 Lexile? So bright kids and HG+ kids may all be reading Harry Potter in 2nd or 3rd grade.
I don't know of any children who read at 3 and then evened out. But I don't hang with pushy parents.
I'd probably agree with that comment about kids reading at three. There is only so much that one can hothouse a kid into doing. I definitely saw kids who were the better readers in grade at age 5-7 who aren't gifted, but kids who read unusually early like at three (and I mean really read not just able to sound out cvc words with a lot of parental instruction), probably are going to turn out gifted or close.
I may have the weird kid, but your comment about younger kids not wanting to read beyond their maturity level did give me a smile b/c my dd14 developed an interest in WWII at age 8 and wanted an explanation for how people could have allowed the concentration camps to happen. She read Stanley Milgram's Obedience to Authority shortly after her eighth bd as a result. I remember that one being assigned reading in a college sociology course I took.
