That is my guess, too, MoN.
DD didn't read particularly early (4, almost 5). I also don't think she walked particularly early (11 mo). The only really good clues that we had until she did learn to read were related to her apparent social skills and observation/memory. She also always did things with pretty much complete mastery once she DID do them. More like quantum jumping than "developing."
My personal pet theory is that the LOG is probably given away more by the rate of complex skill acquisition/development than by age at milestones. A child that slowly acquires a vocabulary of 2K words by 2yo is probably not at the same LOG as one that acquires that same vocabulary over a course of 2 or 3 weeks at two.
That is just my armchair hypothesis-- it's based on the fact that such stories are almost universal among this group's elementary (and older) children who are clearly HG+ and not "leveling out" as older kids, and that even most other parents of GT kids do NOT have such experiences-- at least not the ones I've met. I'm not sure how to 'check' a young child for such a thing, however-- it's mostly opportunistic observation.
