I don't have the studies to cite, but I have the sense that both Iucounu and syoblrig are sort of right. I've never seen anything linking age of reading to specific scores, certainly (as in, reading before 3 = IQ over 140 or something like that). However, I feel like I've seen it stated many times that there is a pretty strong correlation between self-taught reading before age 5 and giftedness, with earlier reading being linked to more profound giftedness. I don't think it's just Ruf, whom I agree is suspect.