Murray and most of race twitter has apparently been fooled by this...



If this is truly full-sibling within-family, the within-pair ancestry SD is ~1–3 percentage points. With that variance and a slope ~0.15 IQ points per pp (≈0.01 SD/pp), you typically need ~20k+ sib pairs to reach p≈.01 even before correcting for ancestry measurement error, which should attenuate the slope further. If strong p's survive with far fewer pairs, the live explanations are half-sib leakage (reintroducing confounds) or selection doing the work.
So to be perfectly clear, my critique is: (i) UKB selection opens A→S←Y even within true full-sib pairs, and (ii) strong p's with small N are inconsistent with full-sib ΔA variance unless half-sibs slipped in or selection is driving results.
Easy way to settle this would be to:
1. disclose the kinship filter (including an IBD2>0 full-sib criterion) and the ΔA histogram;
2. report mean ΔA, σ within(ancestry), residual σ, and an explicit selection strategy (IPW or bounds) with diagnostics;
3. show expected within-family shrinkage for PGS vs admixture in the same sample/spec;
4. if you used a latent g, demonstrate (partial) measurement invariance / DIF checks across groups.
To preempt a misread: there's no basis to invoke any "social channel" within true full-sibs; that's a between-household pathway and would matter only if half-sibs/step-households were mixed in. If I'm wrong, show the DAG/selection model where A→S←Y is irrelevant and the IBD2-based QC that rules out half-sibs, and I'll drop it.


"Every part of this is incorrect"
Murray: Happy to take a look, what's the cite?
*months later, on bluesky*
Murray: Race differences are higher on abstract, culture-free tests



1994: in three or four years we'll see whos right ;)
1995: five years from now
2014: probably less than a decade
2019: within a few years...
2049: (moments before death) any minute now
And now that multiple rounds of these pseudo-analyses have resulted in failure, they've finally graduated to ... just making shit up. /x




















