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0 pointsA_D_E_P_T1y ago0 comments

Heritability is a statistical concept, not a measure of genetic determinism. High heritability doesn’t imply that a trait one exhibits, such as IQ or height, is entirely predetermined by one's genes. Even eye color is only heritable to ~0.98. I'll grant that any trait heritable to 1.0 is indeed entirely predetermined by one's genes -- though, offhand, I'm not sure that such traits exist in humans.

That aside, we're getting into semantics. Whether you call it "genetic determinism" or "heritability," we're talking about durable group differences in genetically-mediated traits. And that is what people may find distasteful or even heretical.

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tptacek1y ago

Are we talking past each other? I'm saying: heritability is orthogonal to the question of whether a trait is determined by genetics. There are traits with no genetic component at all that are highly heritable, and vice versa. "Genetic determinism" doesn't mean "a guarantee that a group of genetically similar people will display a trait"; it means "the trait is causally linked to genes".

The semantics matter, because the evidence supporting HBD positions is stated in terms of the technical definition of heritability.

While I've got you, can I ask that you stop evoking "heresy" and "distaste" in this thread? I believe I'm making simple, objective points, not summoning opprobrium on your position.

A_D_E_P_TOP1y ago

Sure, heritability is orthogonal to the question of whether a trait is determined by genetics.

But traits like IQ, height, and eye color are both (A) highly heritable and (B) substantially shaped by genetic factors. In casual online discourse, I believe that (B) is usually taken for granted, so it's glossed over, and when people say that any given trait is "heritable" they're also assuming that (B) is true for the trait. At least, I am guilty of that lapse.

And I take your point about language.

tptacek1y ago

When you say "substantially shaped by genetic factors", you should present evidence. It's easy to provide evidence for the heritability of intelligence (again, stipulating IQ), but as we've established, that begs the question of whether the genetic connection is correlation or causation. Environments are inherited, too.

There is growing evidence that group IQ heritability isn't evidence of genetic causation.

A_D_E_P_TOP1y ago

There's this: https://pmc.ncbi.nlm.nih.gov/articles/PMC5985927/

First sentence of the conclusion: "Genetic association studies have confirmed a century of quantitative genetic research showing that inherited DNA differences are responsible for substantial individual differences in intelligence test scores."

The trouble is that, like height, IQ is governed by a vast network of "genes of small effect," so a comprehensive view has proven difficult to nail down. Progress is apparently being made, though slowly.

> There is growing evidence that group IQ heritability isn't evidence of genetic causation.

What evidence do you speak of?

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tptacek1y ago

The semantics matter, because the evidence supporting HBD positions is stated in terms of the technical definition of heritability.

While I've got you, can I ask that you stop evoking "heresy" and "distaste" in this thread? I believe I'm making simple, objective points, not summoning opprobrium on your position.

A_D_E_P_TOP1y ago

Sure, heritability is orthogonal to the question of whether a trait is determined by genetics.

And I take your point about language.

tptacek1y ago

There is growing evidence that group IQ heritability isn't evidence of genetic causation.

A_D_E_P_TOP1y ago

There's this: https://pmc.ncbi.nlm.nih.gov/articles/PMC5985927/

> There is growing evidence that group IQ heritability isn't evidence of genetic causation.

What evidence do you speak of?

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