> While having two myopic parents does mean you’re more likely to be nearsighted, there’s no single myopia gene. That means the causes of myopia are more behavioral than genetic.
I agree, but it’s worth pointing out that height is also quite strongly affected by environment (we’ve seen average height grow a lot due to improving diets since the Great Depression).
Everything is strongly affected by the environment. For example, if I butcher you, your height will go down. Also all of your organs will stop working.
But height is not affected by the environment in any meaningful way in a modern first-world context; everyone's diet is already maxed out.
This stinks of faulty logic.