Genetic link between family SES and children's educational achievement

At the speed science and technology are progressing, Darwinian evolution is more or less irrelevant as far as humans are concerned. We'll have IQ enhancing drugs, invented hard AI to take care of us or cured age death long before random DNA mutations or "breeding" adds or subtracts a few IQ points to our descendants. There are a lot of things we should worry about but genetics of future humans isn't one of them in my opinion.

Equal opportunity, not equal outcome or talent.

The Bell Curve (1994) talked about the intellectual stratification that is happening in society. The author and resulting research was called "racist" and has been shouted down time and time again but much of what you say is discussed in the book. He shows correlation between intelligence and [income, parent's socioeconomic status (SES), job security/unemployment, educational attainment, and tons of other things]. The data is sporadic pre-WW2 but complete and well-validated afterwards. He avoids drawing conclusions or prescribing solutions.

All of it is interesting and some is compelling, but the book is generally forbidden to be discussed in "polite" company.

The interesting thing about the book.. to reduce the "racist" attacks, the author only looked at white people throughout the bulk of the book.

Yes, it is a well studied phenomenon called assortative mating.

I think you'll find that birthrates are negatively correlated with education level, so globally the reverse is happening (with regards to your breeding theory).

But more generally, the reason why evolution works is because organisms are not equal (mutation and crossover are random). I don't expect that this will stop any time soon.

j15t gives you the money quote of the results in https://news.ycombinator.com/item?id=12025219

If you just want to know what percentage of variance in family SES is caused by the measured SNP differences, this study puts it at ~20%. This isn't too interesting since we already know that as most SNP GCTAs turn in results similar to that and there are several other studies establishing SES SNP heritability similar to that ( https://en.wikipedia.org/wiki/Genome-wide_complex_trait_anal... ).

This heritability doesn't tell you how the genetics is causing the higher/lower SES, though. It might be because they are increasing intelligence (most plausible); changing personality to more extroverted and Conscientious (possible); or increasing height (possible); or changing preferences to more rewarding fields like STEM (plausible given other results on subject area interest being genetically influenced); or maybe because they are yielding blue eyes/blond hair (highly unlikely). In this case, the researchers look at intelligence, since that is a trait closely linked to SES and also highly genetic.

So what you do is do the GCTA on both SES and intelligence, getting the usual 0.2-0.3 heritability estimates, then you look for overlap. This paper is interesting because it finds a great deal of overlap, indeed, almost total overlap - so you can interpret this as showing that at least part of SES is heritable and passed on in families, not because rich families are better at finding summer jobs for their kids or they leave their kids fortunes in their wills or live in better neighborhoods, but because they give their kids more intelligence genes and intelligence is important for success in modern society.

I don't see how this study is 'presuming' anything. The results section quite early explores the creation between genetic and non-genetic factors:

> To test whether intelligence mediates the observed association between family SES and children’s educational achievement, we statistically controlled for intelligence by regressing GCSE on intelligence and entering the resulting standardized residuals into the bivariate GCTA model with family SES. When controlling for variance explained by children’s intelligence, which yielded a univariate GCTA estimate of 0.38 (0.11 s.e.) (data not shown), the phenotypic correlation between family SES and children’s educational achievement was reduced from 0.50 to 0.37 (0.02 s.e.). The GCTA estimate of the genetic covariation between family SES and children’s educational achievement dropped from 0.25 (0.09 s.e.) to 0.17 (0.09 s.e.). Mirroring the mediation observed at the phenotypic level, this suggests that one-third of the SNPs tagging variation in family SES and children’s educational achievement also captured individual differences in intelligence, implying two-thirds of the SNPs linking family SES and children’s educational achievement were independent of intelligence.

The heritability of IQ and it's effect on SES is well document, but it obviously isn't the only relevant factor. I don't believe equality of outcome is feasible in this regard.

Correct me if I'm misreading, but I have a hard time seeing how the study supports your hypothesis. In the "Discussion" section, the authors state that their heritability estimate for educational attainment was 31%, and only 20% for SES. That still leaves the door open for significant social influence.

The authors summarize: "Our findings add weight to the view that genetic variation plays an important, but not exclusive, role in educational inequalities and social mobility, which is at variance with views, that still prevail in some quarters, that these are solely the product of social forces and environmental inequalities." In other words, they only take themselves to have refuted the strawman view that observed differences "are solely the product of social forces."

A very important part of "long mental time horizon" is picking a good spouse and raising your children well, traits often absent in those who shoot to wealth in one generation.

Families are not genetically stable. There is very little inbreeding in Western societies, so a grandparent and grandchild may not be genetically close.