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Dmitry Vavilov's avatar

How does the rise in Germanic score fit with this data? https://substack.com/home/post/p-179183885 Seems that their scores were pretty low and rose a lot in the late middle ages. Did Italian scores rise similarly around the same time?

Davide Piffer's avatar

The rise in the late middle ages was mostly a British phenomenon

Dmitry Vavilov's avatar

Thank you for the reply. So there was no rise in the last 1000 years among non British Germanics? Then how did everyone end up with an IQ of 100 or around it? Were the brits so much lower then everyone else?

Davide Piffer's avatar

There was a rise but it was smaller. I guess Brits must have started lower as they probably ended up at the same level. I tried to test different models but the sample size is too limited to come to a firm conclusion.

Dmitry Vavilov's avatar

Its very strange that most European populations just ended up with an IQ around 100 on such different paths? What did trigger this explosion in IQ among Germanic tribesmen around 0 AD?

Davide Piffer's avatar

Yea we need larger samples and more spatiotemporal resolution to figure out how they converged. The IQ increase among Germanic people could be due to being in contact with the Roman civilization or the internal struggle between different tribes.

Dmitry Vavilov's avatar

Permanent struggle between barbarian tribes is a norm in most places. Bantu did regularly wage war on each other, as did steppe tribes.

Ted Albert Torrey's avatar

I invariably enjoy reading your posts! But I'm not very well-read in background information. So, I wonder about unavoidable sample bias. For example, who are the 29 Romans ... city elites? Versus the 140/120 northern Europeans ... Teutoburg forest warriors? Certainly it's very unlikely to get great socio-economic correspondence from ancient DNA sources. Thanks for doing these topics!

Davide Piffer's avatar

Thank you. As you said, it is very difficult to get socio-economic data from ancient samples. I could find such information only for a handful of samples. They come from a variety of datasets, sites and labs, so this should reduce the location bias. I am more worried about the cremation customs. The ancient Roman elites for example practiced cremation (if you read Shakespear’s Hamlet you will know Caesar’s body was cremated), whereas the underlcass would often be buried in mass graves, so this would create a substantial bias against Republican Rome IQ in ancient DNA.

barnabus's avatar

My guess would be that elite/non-elite could also have a mass-grave and individual grave burial. So individual burials - especially with supplemental material - could indicate elite. Unless it was some Skythean big-cheese who wanted female company in afterlife... Even in Rome, my guess is that not every patrician wanted to be cremated. Is there a male-female bias in ancient bodies being found? In North-Central Italy and in Scandinavia?

Davide Piffer's avatar

These are interesting questions but I do not have the answer as I would have to check the individual studies for this information. Perhaps it can be the subject of another post. The male–female ratio tells us whether one sex is overrepresented, not whether elites are overrepresented. In the 200 years window around Tacitus' publication, the northern sample is fairly balanced—76 genetically male, 62 female and two unresolved—whereas the Italian sample is more male-skewed, with 20 males and nine females.

That imbalance should not by itself affect an autosomal polygenic score. It would matter only if the sampled men and women came systematically from different contexts for example, war deposits, richly furnished graves or sex-specific burial traditions.

Social status is a separate and more difficult problem. Grave goods and elaborate tombs can provide evidence of relative status within a cemetery, but those

descriptions are not consistently available or comparable across these datasets. Therefore I cannot determine whether either genetic sample contains more

elites, commoners or other social groups. Cremation and site selection remain possible sources of socioeconomic bias, but the sex ratio does not establish

such a bias. Having more information on the burials themselves would allow us to make this inference but unfortunately such data is not coded in the ancient DNA studies. One would have to go through all the supplementary files and parse the text. I tried to do this with AI but it could find social status data only for a handful of samples.

Ted Albert Torrey's avatar

Thanks for the additional information! It's really interesting that ancient Roman DNA results might be biased against elites because of their preference for cremation practices. It's definitely counter-intuitive to my naive expectation.