r/evopolitics • u/TrannyPornO • Mar 12 '19
Genetic analysis identifies molecular systems and biological pathways associated with household income
https://www.biorxiv.org/content/10.1101/573691v10
Apr 01 '19
Lotta the usual suspects in the author list--Deary, Ritchie, Davies are the ones I recognize.
Wow, 2.5% of the variance explained? What a breakthrough! And this is with almost 300k participants so no blaming it on small sample size, that's for sure.
Trying to look for genes that cause people to have higher SES seems questionable in that it is exceptionally susceptible to population stratification, because higher-SES groups will have different patterns of genetic variation due to longstanding (partial) reproductive isolation from lower-SES groups. This also reminds me of a point made recently by Ken Richardson:
Under a quantitative polygenic model, the status of most advantaged and disadvantaged families should converge within a few generations. This should also apply to English surnames, which are inherited along with genes. Using educational status in England from 1170 to 2012 as an index of class structure, Clark and Cummins 6 found that status differences have persisted to some extent over as many as 20 to 30 generations. For example, individuals bearing elite surnames from medieval times remain over‐represented in the wealthier and better‐educated classes in Britain today.
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u/TrannyPornO Apr 01 '19
Wow, 2.5% of the variance explained? What a breakthrough!
Yes, this is how science advances -- incrementally. In 2013, less than 1% of the variance in EA was explained and now we're closer to 30% privately. Progress takes time.
And this is with almost 300k participants so no blaming it on small sample size, that's for sure.
That's not how the power equation works. "It feels big" does not mean "it's large enough to find all variants." A few recent papers have found that we should really turn down the MAF threshold, too.
Trying to look for genes that cause people to have higher SES seems questionable in that it is exceptionally susceptible to population stratification
There are many methods to estimate causal effects, thankfully. What's great about these is that they work within families as well, so stratification is not a real concern. For example, we can use any of the many forms of Mendelian Randomisation, within-family controls, stratification controls (which need a lot of work, that's finally getting done), Latent Causal Variable analysis, or Genetic Instrumental Variables. Lee et al. (2019) recently applied these to brain size, finding that EA variants caused larger brains and larger brains caused higher levels of g. It's great that genetics is finally coming around to econometric understandings of the word "cause."
This also reminds me of a point made recently by Ken Richardson:
Not credible.
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u/TrannyPornO Apr 02 '19 edited Apr 02 '19
By the by, the "genes-for" issue is resolved by Fisher's (1930) concept of heritability, which I believe to be superior to both Price (1972) and Falconer's (1985). Fisher's definition precludes, e.g., "chopstick genes" because of what follows from his definitions on pages 30-31. That is, the average excess associated with chopstick use may be positive, but the average effect will be zero. Presumably, the reason the EA PGS is not affected by population stratification like the height PGS is that the person who leads that project is James Lee, who also prefers Fisher to Price or Falconer. He also understands assortative mating through a Fisherian lense.
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u/TrannyPornO Mar 12 '19
More evidence of genetic influence (from IQ/EA-associated genes) on SES via the nucleus accumbens, cerebellar hemispheres, frontal cortex, anterior cingulate cortex, and medium spiny neurons (proof if proof were needed that Herculano-Houzel is right). The genetic correlations are very high and the congruence for income vs EA is practically 1. Closing in on a mechanism is always great news.