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by tptacek 1393 days ago
Wearing dresses is heritable! Heritability is simply the ratio of genetically-caused variation to total variation for some trait across a population. Bad driving is heritable. So is risk aversion. So is musical taste. So is how much TV you watch. All of these: studied.

Traits can trivially be minimally heritable and totally genetically determined. The number of fingers on your hands is genetically determined by your Hox genes. But the variation in the number of fingers on your hand (more precisely: across the population) is overwhelmingly not genetically determined. Genetically determined, low heritability.

Traits can trivially be maximally heritable and not at all genetically determined. Whether or not you wear lipstick is largely decided by XY vs. XX. But there's no gene for wearing lipstick; if the cultural ball had broken a different way, we might all be wearing lipstick, or none of us. Genetically unencumbered, high heritability.

So: you haven't said anything. You're not even wrong. All you pointed out was that you can do a study and determine that population variations in intelligence (or bad driving, or social trust, or fear of dentists) are traceable to genetic variance. That doesn't mean that genes literally encode the outcome.

Heritability isn't "strong evidence". It's barely evidence at all. It's literally just a framing of the question, which your argument simply begs. Irresponsibly, at that. None of this should be news to you.

I don't even have to take a position on the blighted question of whether intelligence is genetically determined (or whether we can measure it meaningfully at all, or whether it's fixed at birth or fluid, or whether outcomes in intellectual performance are epigenetic). And I'm not. I'm just pointing out that your argument, the one I replied to, was literally vacuous.