If the genetic explanation is true and environment makes no contribution, then I think one should find that IQ is more highly correlated with myopia than academic achievement
It’s like saying “if evolution is true, crocoducks should exist”. You are (deliberately?) misrepresenting opponent’s views. He meant that of all genetic variation affecting IQ, only small, but non-negligible, subset affects both myopia and IQ. However I still don’t quite get how larger brain can cause myopia rather than hyperopia.
Maybe the larger brain leads to more intelligence, and people with more intelligence read more, and reading more leads to myopia. (Whether reading actually leads to myopia can be questioned, but that doesn’t affect the point.)
It’s like saying “if evolution is true, crocoducks should exist”. You are (deliberately?) misrepresenting opponent’s views. He meant that of all genetic variation affecting IQ, only small, but non-negligible, subset affects both myopia and IQ. However I still don’t quite get how larger brain can cause myopia rather than hyperopia.
Maybe the larger brain leads to more intelligence, and people with more intelligence read more, and reading more leads to myopia. (Whether reading actually leads to myopia can be questioned, but that doesn’t affect the point.)