Jonathan Anomaly (@JonathanAnomaly) / X

Pinned

Oct 14, 2025

1/ Today we launch an ambitious paper on the ethics of embryo screening. While the technology is new, our hopes and fears about our future children are as old as the Greek myths, including stories about Hera, goddess of fertility and the namesake of our company @herasight

Embryo selection for cognitive ability is here. The health and welfare benefits are big:

Spencer Moore

@SponceyM

Oct 21, 2025

Today we reveal CogPGT, the world’s most powerful genetic predictor of IQ. We achieve a correlation with IQ of 0.51 (0.45 within-family). Herasight customers can boost the expected IQ of their children by up to 9 points by selecting the embryo with the highest CogPGT score. 🧵

Replying to @brianchau57

Late stage liberalism exalts the Last Man above all others

Polygenic screening can be a powerful way for parents to improve their future children’s health, especially if they have a family history of disease. The best way to promote this technology is to help prospective parents understand it, not to pressure them into using it.

vitalik.eth

@VitalikButerin

Aug 17, 2025

Replying to @tracewoodgrains

I get the appeal. We are told that improving our biology is "unethical", and we want to defend against this charge, and yet we're also often told it's a cardinal rule of public communications that if you're always "on the defensive" you're guaranteed to lose. And so what better

Replying to @JonathanAnomaly

11/ The chart below shows our results, with green cells indicating neutral or beneficial pleiotropy and purple cells highlighting instances of negative (or “antagonistic”) pleiotropy:

Replying to @JonathanAnomaly

3/ Some say embryo screening should be illegal because it is unpopular. But empirical studies show widespread public support for screening health traits, and moderate to high support for psychiatric and behavioral traits, including intelligence (thanks to @RemyFurrer)

Replying to @InezFeltscher

I’ll say it: embryos are not people

Replying to @JonathanAnomaly

4/ Many bioethicists worry about embryo screening increasing genetic inequalities. But genetic inequalities through assortative mating are at least as big as those enabled by embryo screening, and most don’t call for the governments to control mate choice.

Replying to @jeremykauffman

“Nothing makes sense except in the light of evolution” ~Dobzhansky

Replying to @JonathanAnomaly

17/ Read the full paper here: philpapers.org/archive/ANOTEO…

Replying to @BrandonWarmke

Happy to say we did not cite Rawls in this new paper, a blueprint for political theory that combines insights from Aristotle and Darwin:

journalofcontroversialideas.org

Enlightened Tribalism

Tribalism is often derided as a morally primitive form of human organization. But for most of human history, people organized themselves into tribes that facilitated collective action and provided...

Replying to @JonathanAnomaly

10/ We found that where pleiotropy exists, it is almost always neutral or positive, meaning that selecting against one disease is likely to make other diseases less likely to emerge, not more likely.

Replying to @JonathanAnomaly

16/ We end the paper with the objection that embryo screening is a form of “eugenics” and is therefore bad. Our reply is that branding embryo screening “eugenics” with the intent of stigmatizing it does nothing to honor past victims of unethical policies but instead shuts down

Replying to @JonathanAnomaly

2/ We begin the paper by showing how embryo screening promotes two widely accepted values: parental autonomy and the welfare of future children. We then reply to some common objections, including worries about pleiotropy.

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