Uriah

There are two important clues that can help explain what has been driving this effect. The first, as is seen in Eastern Europe and the Caucasus, is that skulls began to shorten as feudalism was introduced. The second is that mountain peoples are almost always brachycephalic.

The best review of old racial anthropology data is Carleton Coon’s The Races of Europe which you can read here https://www.theapricity.com/snpa/racesofeurope.htm … . Coon was almost oblivious to the concept of natural selection, but his data make it clear that mountain living drives brachycephalization.

In the Middle East the most broad faced peoples live in the Caucasus and Turkey. Predictably, the only brachycephalic Arabs are the Lebanese, the only brachycephalic Iranians the Bakhtiari. Assyrians are ultra-brachycephalic, but according to Coon this happened very quickly:

"These Assyrians, whose ancestors, presumably plainsmen from Iraq, may have been no different in a physical sense from the other inhabitants of that valley, are now, after some six hundred years of living in the mountains, more brachycephalic than the Armenians." (87)

One of the countries with the sharpest internal divides in CI is Romania, where people on the plains have mesocephalic values similar to Bulgarians (80) whereas those in mountainous regions like Bukovina are ultra-brachycephalic (85-86).

While mountain peoples are usually brachycephalic, there are exceptions to the rule that help to shed light on the way the process works everywhere: mountain people who practice traditional pastoralism like Kurds and Afghans have retained their ancient skull form.

"All groups of Kurds, however, have not fully escaped this brachycephalization. The Bilikani Kurds, who live among Armenians near Erivan, have a mean cephalic index of 84; others, who live in northeastern Iraq and who are fully sedentary, have (also) been altered".

This makes it clear that it is not mountain living per se, but the sedentism associated with agriculture that is the driving agent here. There is something basically similar in the style of life between these mountainous farmers and those in feudalized regions of North Europe

The common factor is the social environment of village life, which faintly resembles the conditions animals face in a zoo. The best way to understand the distinctive character of Alpine peoples like Slavs is to see them as people of the village.

The first proper W. European villages arose in the 8th century. There is a bit of a chicken/egg debate with regards to feudalism and villages, but villages definitely came first and may have made feudalism possible by making it easier to control peasants https://www.utpjournals.press/doi/abs/10.3138/cjh.48.2.22 …

In both Europe and the Caucasus feudalism was accompanied by the introduction of new heavy plows, the carruca and Caucasian gutani which allowed for the exploitation of heavier soils. The gutani was pulled by a team of 16 oxen, which necessitated communal ownership of livestock.

It didn’t work this way exactly everywhere but the general trend was heavy plows pulled by many oxen> communal ownership of animals and land>villages> feudal exploitation.

Feudalism is a broad term, and feudalism was more transient in some countries (England) than others, whereas some got off scot-free (Norway). My definition of a "feudal country" is one where the labor demands of lords were imposed for the better part of a millennium.

In places in which women perform real physical labor they often quit breastfeeding early and sometimes avoid the practice altogether, as was the case until recently in Catholic Germany and Russia. The effects on infant mortality were horrendous.https://twitter.com/crimkadid/status/1334934056874676224 …

There’s a correlation of about -0.5 between % lactose tolerant and the CI: e.g. French are the most wide faced and LI people in Western Europe. Feudalism seemed to interrupt selection in this area; the only people who ended up lactose tolerant and brachycephalic are the Germans.

By any standard the lives of these peasants were harsh, but there’s something that made it worse. Many tasks were performed by the community and there were long days peasants spent surrounded by others, not just friends or family, but everyone: people they didn’t like, assholes.

Other than maybe Jews or Parsis no one is truly adapted to city life, because high mortality from diseases made old cities population sinks. The active community life and cooperative agriculture in rural villages though produced much the same effect.

Feudal communities were practically states within themselves. Because lands and animals were communally owned, they were jealously guarded and interlopers were automatically assumed to be thieves. A peasant spent his whole life in a glorified pen.

Agricultural life in mountains resembled feudalism in that it required constant cooperative activity and geography naturally restricted movement in much the same sense feudal lords did: you only have so far to wander when boxed in mountains.

Peasant life was a thresher. The people who couldn’t cut it were partly those who couldn’t meet the physical demands without succumbing to exhaustion and infection, but also those who felt penned in, who dreamed of what life would be like on the other side of the mountain.

Okay, so life was stressful, but what does that have to do with skull shape? Why do different species of domesticated animals invariably end up with short, broad skulls?

Two researchers at Harvard made note that in animal studies high levels of glucocorticoids inhibit the outward development of the upper jaw. They decided to measure if the same relationship between skull form and stress reactivity occurred in humans: https://sci-hub.se/https://srcd.onlinelibrary.wiley.com/doi/abs/10.1111/j.1467-8624.1995.tb00950.x …