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Heydocbrown's avatar

the proper starting point on claims of human genetic determinism is skepticism.

I am professional agricultural researcher. So I can answer many of these questions in a general sense from lived experience of design and analyzing experiments. It is much harder to be confident about how they apply to humans for three reasons.

First, humanity is a young species, so its genetic diversity is very low. Two wild varieties (called “landraces” in the uhh… historic… technical vernacular) of corn have 99% of the same genes. A human has 99% of the same genes as a chimpanzee and >99.9% of the same genes as a very different human of the same genetic sex.

Second, best practice experimental practices for determining genetic vs environmental components of a trait (e.g. intelligence, or how tall corn is) are completely unethical for humans - replicated controlled trials. You would go to jail for them.

Third, humans are smart & social animals, which makes them engines for experimental confounders and provides a non-genetic reason for a trait to be heritable between generations.

This all makes determining what is intrinsic vs extrinstic for a human fiendishly hard.

To your specific questions:

Brain structure to function - if you figure this one out, you get a Nobel prize.

Animal cognition affected by genome - 100% true and proven in livestock.

Intrinsic dispositions, fraternal twins - maybe? but what if we're really sensitive to random stimuli in the womb? Or what if in a different environment very different than our current human society, the genetic intrinsics would express differently. Confounders.

How come school experiments don't work? - as you can't do well-controlled experiments on humans, why would you expect these experiments to tell you anything causally?

So the total environmentalists are wrong, but the genetic determinists (especially the really truly racist set) are taking data from weak experiments to make strong claims.

The genetic determinist claims out there are the sort that are hard to prove on crops and livestock, where we can use experimental techniques like replication and controlling the entire lifecycle of the experimental subject from birth. And even for corn, strong causal claims are hard to make.

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Feral Finster's avatar

"Over a long enough timeframe, conditions on social media ensure that pretty much all subcultures devolve into sneering comedy clubs." DeBoer's First Law.

By turning everything into a series of hot takes and snarky one-liners for the attention-challenged, the internet may well be the death of us all.

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