“Stereotypical nerd appearance, often lampooned in caricatures, can include very large glasses, braces, buck teeth, severe acne and pants worn high at the waist.”
"This surprised me - the conclusion is that most of the connection between myopia and intelligence is explained by genes and not environment (i.e. reading)."
That's because you incorrectly assume that variation in reading habits has non-genetic causes. A genetic correlation between two such things might simply result from a shared cause from equally genetic basis with interest in reading or something. In real life, things are more complicated, but you get the idea.
"This surprised me - the conclusion is that most of the connection between myopia and intelligence is explained by genes and not environment (i.e. reading)."
That's because you incorrectly assume that variation in reading habits has non-genetic causes. A genetic correlation between two such things might simply result from a shared cause from equally genetic basis with interest in reading or something. In real life, things are more complicated, but you get the idea.