Thread by @SashaGusevPosts

Murray and most of race twitter has apparently been fooled by this completely fabricated analysis purporting to show African ancestry is associated with IQ. People lie on twitter all the time, but this is both more revealing and more disturbing than usual. A 🧵

https://twitter.com/charlesmurray/status/1968053071847760235

Revealing in that it shows how quantitative racism is a just an exercise in manipulating data to fit the preconceived conclusion. Disturbing because this time private data is being used and the results, which cannot be easily verified, are just flatly invented.

What's actually going on? Some guy claims to have an analysis showing that African ancestry differences between siblings are associated with IQ differences in the UK Biobank. Implying an ancestry difference in the within-family influences.

But there's an obvious glaring error: in the same analysis, African ancestry was *not* associated with darker skin! Which would mean ancestry-specific alleles DO NOT have a direct influence on skin color. Pigment is, according to these guys, a social construct.

We, of course, know that alleles influencing pigment differ across populations, and that more African admixture is associated with darker pigment. Anyone honestly looking at this result would realize something went wrong and try to debug it. But not this crack squad.

Instead, the result is forced to fit the narrative. We get a whole wall of text about how sparse traits like skin color won't actually correlate with African admixture. This makes zero sense. And you'll notice the model is never actually derived, just argued on faith.

When we look in papers that actually derive a model (), we can see that the derivation does not depend on sparsity at all. The analysis estimates the difference in direct genetic values regardless of the trait architecture. medrxiv.org/content/10.110…

Or we can use our intuition: for a sparse trait, siblings will either have no trait differences or very large differences; for a non-sparse trait, siblings will often have small trait differences -- it's a wash. Sparsity impacts the variance and not the estimate.

Or we can just simulate it (): generate admixed families with a heritable trait that has allelic differences between populations, and confirm that the sibling analysis accurately recovers the true difference. It does! Regardless of sparsity. gist.github.com/sashagusev/b92…

So the analysis is clearly bogus from theory, intuition, or simulation. Why invent a ridiculous explanation for it? Because the fake result is *useful*. If ancestry doesn't impact skin darkness, then one can claim that 'colorism' is not a relevant mediating factor.

One other point you might notice in the simulation is it takes tens of thousands of siblings to get an accurate estimate. Within-family ancestry variance is low, and so the number of families needed for statistical power is very high. This is also a well known result.

The recent Wang et al. analysis used ~17,000 siblings with more ancestry variance and still had a standard error of ~0.25. Earlier, the blogger gwern ran power calculations and came to a similar conclusion (): gwern.net/note/statistic…

The UK Biobank analysis purports to have a much tighter standard error (~0.13) so how many sibling pairs did they use? Hundreds of thousands? Nope ... 175! That's right. They looked at 175 families and concluded that racism is real once and for all.

At this point it should be clear that we're dealing with complete bullshit. For the interested, a longer discussion (), with multiple derivations coming to the same conclusion. The accounts behind the analysis don't even bother to respond.

https://x.com/BuzzLightworth/status/1968035912077701195

I'm belaboring the point is because it is endemic of the broader quantitative racism project: find data that fits the narrative, fake it if necessary, and when someone finally points out the errors, the time for argument is past and we move on to a new spectacular claim.

First, it was individual candidate genes that had massive influences on behavior and cognition. When these failed to replicate spectacularly, the excuse was that the *theory* still made sense (ironically, this claim was recently deleted!).

https://x.com/SashaGusevPosts/status/1964345901641605322

Then it was the claim that heritability estimates themselves could be manipulated to prove the genetic differences between groups. When this was mathematically disproven (), suddenly people like Murray lack the rigor to evaluate it. pubmed.ncbi.nlm.nih.gov/38470926/

Then it was the claim (borrowed from Jensen) that IQ tests cannot be driven by culture because more g-loaded subsets are more "culture free". When this too was shown empirically to be the exact opposite of the truth ... crickets.

https://x.com/SashaGusevPosts/status/1932949513024729474

Then it was the claim that genetic scores for IQ are lower in African samples. When a proper analysis revealed the results to be completely *flipped*, this did not lead to a sudden interest in African genius -- the earlier claim was simply forgotten.

https://x.com/SashaGusevPosts/status/1905739085618274697

Then it was the claim that admixture correlates with IQ. When this too was pointed out to be environmentally confounded, lo and behold: a set of 175 sibling pairs was immediately identified and manipulated to make a bold new result. And here we are.

https://x.com/SashaGusevPosts/status/1966309649743048831

In each instance, the goal was not to get at some underlying truth, but to add more bullshit to the conversation faster than careful people can refute it. Create the appearance that the prophecy is always coming true but ~they~ are hiding it from you.

https://x.com/evopsychgoogle/status/1188441459860443137

Coming back to Murray and Jensen. Murray, frankly, should know better. But at this point he's basically a victim of elder abuse: high-tech scams that he himself does not even pretend to understand and merely echoes because they fit the narrative he spent his life cultivating.

Jensen, for all his ugliness, at least attempted to do research. He went out into the field and collected data and tried to report the results. But this new generation of Jensen-ites is different: truth is irrelevant, they can simply put on the performance of doing research ...

... grabbing data, forcing it to fit, constructing elaborate epicycles to explain inconvenient results, then abandoning them as convenient.

And now that multiple rounds of these pseudo-analyses have resulted in failure, they've finally graduated to ... just making shit up. /x