There has been a flurry of discussion on missing heritability over the past few weeks, so I want to highlight a few articles worth reading for different perspectives on the topic. I have quoted some sections I found most relevant alongside my own commentary (which conveniently lets me get the last word in), but I encourage you to read them in full.
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Kathryn Paige Harden has a typically thoughtful piece on what is actually interesting about missing heritability (and missing “environmentality”):
Heritability is missing, but so is environmentality. Let’s say we halve every heritability estimate from a classical twin study, presuming that the estimate is inflated, and attribute that variance to the “shared environment.” Where are the causal effects of specific environmental influences that add up to anything remotely close to that shared environmental variance component? They don’t exist. Even when you change literally everything about a child’s life by adopting them into an entirely new family, or adopting them out of hellacious institutional care, you still don’t get effect sizes big enough to explain the incredible similarity of identical twins. The “missing heritability problem” is just another manifestation of a much more general problem—the granularity problem, the reductionism problem. Human lives are both undeniably structured by naturenurtureluck and very poorly predicted by individual variables, at least the ones we currently know how to measure.
From the blog post:
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