Within-Family PGS was said to prove definitive causal SNP’s and even though they generally give 1 or 2% of the variance explained, this was being held onto as proof of something, as Harden stated in her book, The Genetic Lottery, “... the heritability of educational attainment is still not zero.” Now that is (not surprisingly) being called into question with this simulation study:
A model for co-occurrent assortative mating and vertical cultural transmission and its impact on measures of genetic associations.
The study notes that GWAS are still beset by confounding, noting:
“Furthermore, we show that such inflation remains even when applying within-family based estimates.”
For the past 3 decades, behavioral genetic studies have relied on the fact that their assertions take a few years to be disproven and, by the time that happens, they have new assertions - rinse and repeat.
