Share this page!

Enter URL or ID to Unroll

You can paste full URL like: https://x.com/threadreaderapp/status/1644127596119195649
or just the ID like: 1644127596119195649

How to get URL link on X (Twitter) App

  1. On the Twitter thread, click on or icon on the bottom
  2. Click again on or Share Via icon
  3. Click on Copy Link to Tweet
  4. Paste it above and click "Unroll Thread"!
  5. More info at Twitter Help
Sasha Gusev Profile picture
Sasha Gusev
@SashaGusevPosts
Statistical geneticist | Associate Prof at @DanaFarber / @harvardmed / @DFCIPopSci | Blogging at https://t.co/4D7UObBNdd
5 subscribers
Oct 14 • 7 tweets • 4 min read
Eric Turkheimer has a good piece about a bet he made with Charles Murray regarding the genetic understanding of IQ (or, really, the lack of it). Murray being so wrong in his prediction should make us question his world model, but it's also worth commenting on his response. Image Murray has, for some time now, been workshopping the excuse that progress on IQ genetics was blocked by researchers being denied the access to the relevant databases. This is patently untrue! Image
Sep 18 • 24 tweets • 9 min read
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 🧵 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.
Aug 1 • 14 tweets • 6 min read
A few thoughts on Herasight, the new embryo selection company. First, the post below and the white paper imply that competitors like Nucleus have been marketing and selling grossly erroneous risk estimates. This is shocking if true! 🧵 I wrote last year about the un-seriousness with which Nucleus approached their IQ product and the damage it could do to genetic prediction and research more broadly (). This appears to have been a broader pattern beyond IQ, extending even to rare disease.theinfinitesimal.substack.com/p/genomic-pred…
Jun 24 • 12 tweets • 5 min read
Oof. Polygenic scores for IQ lose 75% of their explained variance when adding family controls, even worse than the attenuation for Educational Attainment. These are the scores Silicon Valley is using to select embryos 😬.

A few thoughts on this study ... The TEDS cohort used here is a very large study with high-quality cognitive assessments collected over multiple time points. It is probably the most impressive twin study of IQ to date. That means very little room for data quality / measurement error issues.
Jun 17 • 4 tweets • 1 min read
@notcomplex_ @krichard1212 The authors fit a non-identifiable Model B, which produces a table full of NA's. Then they try to interpret this model to fix it. That makes no sense. The parameters of this model will be completely arbitrary, so using it to decide what to prune is also statistically invalid. @notcomplex_ @krichard1212 At various points later on they talk about "Heywood cases", which are out-of-bounds parameters or negative variances, but no such out-of-bounds parameters are actually present in the tables (and, again, you cannot interpret these from the non-identified model).
Jun 11 • 13 tweets • 6 min read
Racism twitter has taken to arguing that observed racial differences must be "in part" explained by genetic differences, though they demure on how much. Not only is this claim aggressively misleading, it is completely unsupported by data. A 🧵: Image
Image
Image Genetic differences between any two populations can go in *either* direction, matching the phenotypic differences we observe or going against them. Genes also interact with the environment, which makes the whole notion of "explaining" differences intractable. Image
Jun 6 • 19 tweets • 9 min read
James Lee and @DamienMorris have an interesting perspective paper out describing "some far-reaching conclusions" about the genetics of intelligence. This type of "where are we now" paper is very fun and more people should write them! So, where are we now? 🧵 Image It's a short paper and it surveys three core findings from the past decade of intelligence genetics. These sections follow a structure that I would cheekily call ... "make a bold claim in the title, then walk it back in the text".
May 20 • 5 tweets • 2 min read
The SAT/meritocracy debate has always been a bit odd to me when the test makers themselves have studies showing self-reported high-school GPA is a consistently better predictor of college GPA and always adds on top of SATs. Image Clearly SATs are neither the only nor even the best measure we have of college success and "holistic" admissions can be "meritocratic". It's up for debate whether the additional <10% predictive variance SATs give you are worth the high-school testing industrial complex.
May 11 • 11 tweets • 6 min read
Hanania advocated passionately against "race mixing" for years, so he knows what he's talking about here. But it's worth adding that race-IQ obsessives also tend to make very poor predictions about the future. Let's review ... The Bell Curve, published at the peak of the 80-90's crime wave, predicted a coming dystopian urban hellscape with a "cognitive underclass" living in state-managed facilities. Not only did all this fail to materialize, but crime rates collapsed.

Image
Apr 27 • 18 tweets • 8 min read
Nice! Here we have an interesting paper using genetic ancestry to classify race/ethnicity in modern data and algorithms. Let's take a look at what this paper found: 🧵 First, I don't want to get too hung up on language, but TCB's tweet starts talking about "ethnicity", then shifts to "continental ancestries", and then entirely omits the largest ethnic group in the US: Hispanics. These terms have distinct definitions (). nap.nationalacademies.org/catalog/26902/…Image
Image
Apr 26 • 5 tweets • 3 min read
Always a red flag when people cite a 20yr paper for a question we have much better data on today. On the left is the race/ancestry clustering from Tang et al 2005, and on the right is the race/ancestry clustering for modern biobanks collected over the past few years. Image
Image Of course you can also find similar looking patterns of structure within self-reported race/ethnic groups: (a) white Europeans, (b) white Brits, (2b,c) China, (2f) Canada, (2e) Japan. Image
Image
Mar 28 • 15 tweets • 6 min read
I wrote about how population stratification in genetic analyses led to a decade of false findings and almost certainly continues to bias emerging results. But we are starting to have statistical tools to sniff it out. A 🧵: Image First, stratification = genetic structure + environmental structure. If two populations have some genetic variation (e.g. due to drift) and differing environmental influences on a trait, that will induce a false/non-causal correlation between genes and the trait. Image
Mar 14 • 10 tweets • 5 min read
This is a good example of how pointless a lot of the "data oriented" conversations on X are. DataRepublican, a DOGE analyst, makes a bold claim that 0/60,000 sampled government contracts had outlays < potential award ... Image
Image
Image Judd Legum, a journalist, points out that having outlays lower than the potential award amount happens frequently, explains why, and highlights a number of specific examples. Seems like a pretty basic error, should be easy to acknowledge right?

Mar 3 • 7 tweets • 3 min read
So it turns out the person running this account and accusing mainstream behavioral geneticists of fraud was actually one of the authors of the discredited Pesta at al. paper that was being criticized. Pretending to be an objective third party so they could sling mud. FWIW I don't have a problem with anon accounts and enjoy interacting with many on here. I understand that people may want to partition their on-line/IRL lives. But setting up a sock puppet persona so you can aggro out on colleagues that disagree with you is pathetic.
Feb 23 • 4 tweets • 2 min read
It's been interesting seeing Murray become an Ibram X. Kendi figure but for the right. Everyone knows his "analyses" in Human Diversity -- like comparing non-causal allele frequencies between populations -- are completely bogus. Razib knows this too. But Murray says the things that are politically correct and pleasing to that audience's ego so he regularly gets trotted out for softball interviews and never needs to exhibit any rigor.
Feb 21 • 9 tweets • 4 min read
This thread and especially the underlying LessWrong post are a good demonstration of the IQ super-baby conspiracy theory that seems to be gripping Silicon Valley. Here's how it works ... First, claim that we already have the knowledge of how DNA affects college graduation rates but no one is interested in applying it. This is false, we almost never know *which* genetic variant is actually causal nor *how* it actually influences the associated trait. Image
Jan 20 • 7 tweets • 3 min read
How population stratification makes environments look like genes. A short 🧵: Image Start with two populations undergoing neutral drift but with no frequency differences on the alleles that influence the trait (i.e. no genetically causal population differences). Image
Jan 15 • 7 tweets • 5 min read
This account is a firehose of quantitative racism but it is worth re-iterating that: if a trait like skin color is caused by genes, and society determines outcomes based on skin color, then -- yes -- those outcomes will also be heritable. This is heritability 101! Image The fact that these guys were able to cook up a simulation that "disproved" a hypothesis that any intro genetics student knows is TRUE is a testament to how much nonsense people can get up to on here with a poor grasp of R and ggplot. Image
Image
Image
Nov 24, 2024 • 9 tweets • 4 min read
I wrote about the National Institutes of Health and the various serious and unserious proposals for NIH reform that have been floating around. It is important to understand how this agency actually functions and point criticism at the right problems. A short 🧵: Image The vast majority of the NIH budget goes towards funding research proposals in some form. I walk through the grant review process but the takeaway is that proposals are evaluated by groups of scientists on importance + rigor and most proposals *do not get funded*. Image
Image
Nov 2, 2024 • 11 tweets • 5 min read
I wrote about the evidence for selective sweeps from genomic data over the past 50,000 years. A few highlights: Image Accurately detecting loci under selection is complicated by three main factors: neutral drift (which adds noise to allele frequencies), gene flow (which can hide or falsify frequency changes), and background selection (which induces more drift and temporal covariance). Image
Image
Image
Image
Oct 30, 2024 • 10 tweets • 4 min read
One thing that has been difficult to understand from the election coverage is how Trump's policies are going to impact *me*, a rootless cosmopolitan and an Ivy League professor. Let's take a look: I'm on the right side of this chart, so Trump is going to blow up the deficit to give me a tax cut, while 40% of households get effective tariff hikes. Is this populism? Image