A post I recently made on another thread may be of some significance:
"It may be worth noting that myopia correlates positively with IQ, and that this correlation is not extrinsic (i.e., not the result of cross-assortative mating). This is confirmed because studies have found that the correlation between myopia and IQ still exists among gifted and non-gifted siblings. One can not say the same for, e.g., the correlation between height and IQ, which exists in the general population but is nonexistent among gifted and non-gifted siblings. In other words, the correlation between height and IQ only exists because both height and intelligence are valued by society, and thus tall and intelligent people are more likely to procreate."
I should also note that myopia is essentially caused by a single gene that codes for the shape of the eyeball, which suggests that any such genetic relationship between myopia and high intelligence is pleitropic in nature. Classrooms allocated to gifted students, for example, show rates of myopia three to five times higher than that of the general population. The belief that excess time spent reading and the like results in a diminution of eyesight among the gifted has been essentially defunct since the 1980's, and the vast majority of extant researchers agree that the relationship is genetic, rather than environmental, in nature.
Last edited by Frank22; 08/08/14 05:52 PM.