Ed Seabright

High rates of polygyny do not lock large proportions of men out of the marriage market | PNAS There is a widespread belief, in both the scholarly literature and the popular press, that polygyny prevents large numbers of men from marrying by ...

🚨 The Economist has been telling you for years that polygamy causes civil war by locking men out of marriage. A new article with @rebeccasear.bsky.social and @anthrolog.bsky.social explains that the demography of marriage markets doesn't actually work that way. 🧵

www.pnas.org/doi/10.1073/...

#HBES2026 abstract submissions are live! More exciting details to come soon.

Arrive early for @ces2026.bsky.social

@humbehevosoc.bsky.social

We’re delighted to share that the CES2026 Conference website is now live!

We warmly invite researchers, scholars, and practitioners to submit their presentation proposals by November 16th through the submission portal on the website.

if you ask it to write a whole paragraph or more from scratch, it's pretty bad. If you give it a sentence that you know sounds wonky, but you're not sure how to improve (eg because you're writing in a second or third language), it can be helpful.

It's easier to notice when a sentence is well written than to write a good sentence yourself. I don't personally use LLMs to write, but my ESL students do, not to draft from scratch but in cases when they aren't sure how to phrase something. LLMs can give them options, and they can pick their fave

My criterion for whether an LLM can be useful is when it is difficult to find a solution to a problem, but easy to verify that solution (like cryptography). If I am coding in a language I'm not familiar with, I can ask "how can I best achieve this outcome?" and then easily check whether it works

The graph says nothing about whether people are using it to improve at things they are not good at. If you assume that everyone is using it to replace their brain in each of these areas, then sure, that's bad - but that's not what was asked. The survey just asks in what domains people use it.

It's not meant to be used for things you are good at, it's meant to help learn tasks or skills you don't currently have.

You can't ask google translate: "suggest other ways I might phrase this", and then pick your favourite. Very useful for non-english speakers, or even people who are learning to write well.

Miyagawa Shuntei's 1898 painting, "Playing Go (Japanese Chess)"

How to quantify the impact of AI on long-run cultural evolution? Published today, I give it a go!

400+ years of strategic dynamics in the game of Go (Baduk/Weiqi), from feudalism to AlphaGo!

Abstract submission now open for the next Cultural Evolution Society conference in Rabat, Morocco next May @culturalevolsoc.bsky.social @ces2026.bsky.social

Transmission networks of long-term and short-term knowledge in a foraging society Abstract. Cultural transmission across generations is key to cumulative cultural evolution. While several mechanisms—such as vertical, horizontal, and obli

💙New paper!💙

How is knowledge transmitted across generations in a foraging society?

With @danielredhead.bsky.social
we found: In BaYaka foragers, long-term skills pass in smaller, sparser networks, while short-term food info circulates broadly & reciprocally

academic.oup.com/pnasnexus/ar...

We are delighted to announce that the CES2026 conference website is now live! We invite you to submit your presentation proposals using the link on the webpage, deadline November 16th:
airess.fgses-um6p.ma/ces2026

The count down starts for #CESRabat! Follow @ces2026.bsky.social and join us May 11-13 next year for an exciting meeting in Rabat, Morocco.

Massive thanks to the #CESRabat organising committee:
Sarah Alami (co-chair)
Mathieu Charbonneau (co-chair)
Zachary Garfield
Edmond Seabright

Happy birthday!

I would settle for academic types reliably making this distinction

I also don't like the title much. A spectrum is not a rigorous or even useful metaphor for understanding a multi-trait phenotype like sex, in my opinion.

So thanks for the review, Ed.
I hope people don't just take home the idea that sex is simple, and people who disagree with that are wrong.

in their multi-faceted glory. And it is important and relevant to make that point, and to push back against unscientific essentialism.

I haven't read the Fuentes book. It doesn't sound like it clearly distinguishes between sexes and sexual phenotypes, which is a shame.

that science is irrelevant, that these are Gouldian "non-overlapping magisteria", and that people arguing that sex is not binary are just plain wrong, albeit for possibly well-meaning reasons. I disagree here. Most people arguing that sex is not binary are actually talking about sexual phenotypes,

irrespective of the complexities of people's biological realities ("Caster Semanya is *really* a man").

Ed Hagen is very keen to emphasise the scientific value of the binary nature of the sexes, in an evolutionary sense, and I sympathise and agree. But when it comes to political issues, he argues

"it is impossible to change one's sex" - false, or at least incoherent, insofar as there are multiple traits that characterise a person's sex, and it's possible to change many of the important ones. This leads to a sort of weird, essentialist insistence that everyone has a "true" sex

So "there are two (evolved) sexes" and "sex(ual phenotypes) are not binary" are actually perfectly compatible statements, but people constantly use one to argue against the other. So you hear people say "there are only two types of gametes" (true) and use that to argue

Individual sexual phenotypes, on the other hand, are the result of a whole host of traits: chromosomes, genes, primary and secondary sex characteristics, hormones, etc - and are absolutely not binary, even if most individuals align very strongly with one of the two sexes.

The problem with this conversation is that people dont distinguish between "sex" and "sexual phenotype". The first, as Ed explains, is not actually a property of an individual, but rather a set of options in an evolutionary game theory setup. There are indeed only two of these sexes (in mammals)

Very disappointed that we were forced to cancel our field season and return early, following the suspension of our NSF grant as part of Trump’s attacks on UCLA. Particularly sad for our students, who spent significant time and effort to join us this year.

Jane Lancaster and Human Nature - Human Nature Human Nature -

The great Jane Lancaster has passed away. She was a titan and very kind to me all the years I was at UNM. See a tribute from her friend and mine, Bob Hitchcock here:

link.springer.com/article/10.1...

Jane was a force of nature, a brilliant mind, and a lovely person. Human behavioural ecology owes her so much.

Macron's meglomania is usefully adaptive in certain circumstances.

French President Macron says France will recognize Palestine as a state French President Emmanuel Macron has announced that France will recognize Palestine as a state, amid snowballing global anger over people starving in Gaza.

French President Emmanuel Macron has announced that France will recognize Palestine as a state, amid snowballing global anger over people starving in Gaza.

That's awesome, congratulations!!