**update below**

here’s a map created by jayman of average european iqs (taken from here), and on top of it i’ve added the hajnal line:

the populations behind the hajnal line (i.e. the core of europe) are characterized by:

late marriages (present since at least the early medieval period)
small family sizes (nuclear or stem families versus extended families; also present since at least the early medieval period)
– higher average iqs, in general, than populations in the periphery of europe (see map)
strong future time orientation, strong societal collectivism, strong preference for rules and order (Ordnung!), strong drive to succeed
– being more civic than populations in the periphery of europe


well, maybe it’s just ’cause these populations are mostly germanic, or at least had a strong-ish germanic presence in their territory at some time in the past. maybe this is just an example of ice peoples who evolved high iqs and a lot of other neat traits ’cause they survived for a long time in adverse conditions.

but’s it’s hard to ignore how the Type A Personality areas of europe coincide with the hajnal line. at least, i find it hard to ignore. what happened behind the hajnal line?

at the risk of repeating myself (is there an echo in here?), what happened behind the hajnal line starting in the early medieval period was:

– changes in mating patterns (thanks to the church) from close relative marriage to more distant marriages, thus breaking down clans and tribes
– changes in the economic structure from whatever the h*ll went before (i have no idea) to manorialism
– changes in family structures (thanks to both the increased outbreeding and manorialism) from extended families to smaller nuclear or stem families

all of these would’ve changed the selection pressures on the populations in the areas where these practices were adopted.

inbreeding and outbreeding probably select differently for genes related to altruism, so all of the outbreeding behind the hajnal line likely selected for different sorts of altruistic behaviors than those seen in other populations — strong societial collectivistic feelings, for instance. (perhaps it looks something like this.) the changes in family structures likely also selected for different traits — for one thing, different family types have different family dynamics and some personality types likely do better in some types of families than in others.

but what’s manorialism got to do with it? like i said here

“you have this manor system in which the lord (or monks) of the manor let out land to farmers to run (they then owed the manor service or rent). the lord of the manor specifically let out land to married couples, ’cause it took two to run a small farm properly, i.e. to carry out all the necessary duties…. so who is a young and upcoming, hard-working, driven farmer going to seek out to marry? well, maybe he just marries the prettiest girl he can find — but maybe, if he’s smart, he marries someone like himself who is also hard-working and driven and wants to run a successful manor holding. they might even be attracted to one another. maybe it was exactly those sorts of couples — the smart, hard-working, industrious couples — who were the most successful and left the most descendants behind.

…so maybe manorialism contributed to higher average iqs and traits like “strong drive to succeed.”

where did manorialism occur? it started with the franks as early as the seventh century in their territory between the seine and the rhine. it was a characteristic feature of the carolingian empire and was pretty much present throughout carolingian territories.

it was introduced to northern, but not southern, italy by the carolingians. southern italy was part of the byzantine empire so manorialism wasn’t introduced there in the early medieval period, nor was it adpoted there later in the middle ages. manorialsm never took hold in greece or the balkans.

manorialism was present in england by the eighth century, but not scotland or ireland or wales. the normans brought it to ireland in the eleventh century, but its adoption was patchy at best. southern spain did not experience manorialism due to moorish rule, but parts of northern spain did.

manorialism spread eastwards during the ostsiedlung and was really the fundamental economic structure of the german settlements to the east. the system was also introduced, as late as the sixteenth century, to eastern regions of europe like poland and belarus. the eastern edge of the hajnal line — where the western and eastern churches meet — represents the limits of the manor system in europe.

the populations behind the hajnal line have a unique history (well, all populations do!) and, i think, were very much shaped in a human biodiversity sort-of way during the medieval period. there were strong selection pressures precisely in areas related to mating and reproduction that really profoundly changed northwestern/central europeans and laid the foundations for all sorts of interesting things that happened in europe. it may have also laid the foundations for our demise, but hey — you can’t have everything.

none of the populations in the periphery in europe experienced this collection of changes. they may have experienced some of the changes — like the ban on cousin marriage out to second cousins in greece and eastern europe — but because they didn’t have the manor system, they did not develop nuclear families or highly mobile individuals like the core of europe. and some populations, like the southern italians and the irish, in addition to not adopting the manor system, also just kept right on inbreeding up until very recently.

here are some excerpts from michael mitterauer’s “Why Europe?: The Medieval Origins of Its Special Path” from which i learned everything i know about manorialism [pgs. 53-57]:

“These cross-cultural examples of analogous, and markedly contrasting, agricultural systems illustrate the uniqueness of the manorial and the hide systems as they developed as components of the early medieval agrarian revolution in the Frankish heartland. The diffusion of innovations from the agrarian economy and the agrarian system very often took place in concert — as, for instance, during the great process of the colonization of the East. This was not true in every case, of course. The manorial system expanded southward, following the Frankish Empire’s specific forms of lordship and penetrating into regions where typical features of the Frankish agrarian revolution did not exist. A large, relatively homogenous area was created by these expansionist movements, which were characterized on the whole by identical or similar structures of the agrarian system and the social order it generated. Over against this ‘core Europe’ was a ‘peripheral Europe’ that did not acquire these structures until a relatively later date — or not at all. Here we can list Ireland, Wales, and Scotland in the West; the area of eastern Europe beyond the Trieste-St. Petersburg line that was unaffected by the colonization of the East; the entire Balkan region; southern Italy, which was formerly Byzantine, along with the southern part of the Iberian Peninsula that was under Moorish rule for so long a time. The political, economic, and social evolution of many regions in ‘peripheral Europe’ took a different turn because of their clinging to other, traditional agrarian systems.

“As Frankish models of the manorial system advanced through various parts of Europe, they met with quite diverse forms of social organization. In the North and East it was mainly tribal societies that were transformed by the new structures of the agrarian reovlution. They could be organized in very different ways, as was evident in medieval Europe. When Germanic tribes settled on Roman imperial land — the Franks, Burgundii, Alemanni, and Bavarii among them — categories of descent as a basis for social order played a role, a role very different from the one it played in the thinking of Celtic tribes in Ireland or of Finnish and Baltic tribes around the Baltic Sea. Consequently, the resistance of the various tribes to manorial structures was highly differentiated from region to region. In many places these structures rapidly superseded more ancient types of tribal organization; in many others, not at all. We can say that the manorial system and the tribal system were basically incompatible at the social level of the peasantry. The economic rationale for an agriculture based on manorialism cannot be harmonized with dominant organizing principles based on kinship. That proved to be the case throughout Europe wherever the social organization of the manorial and hide system supplanted tribal structures. In many non-European empires, the lack of such organizations might well have contributed to the local preservation of social forms based on descent in spite of strong influence of a central state — for instance, in China and the Islamic world….

“The manorial system of the Carolingian Empire was premised on the personal relationship of the lord with his familia [all of the people who lived and worked on the manor, most of whom were not related to one another]. This principle continued to have a more or less potent effect on every form of the manorial system that grew out of it. Any and all lordship in this tradition was lordship over a group of people organized ‘as a family….’

“Manorialism and the hide system were just as significant for European social history on the macro level of organized lordship as they were on the micro level of household organization. Claude Levi-Strauss has coined the term societe a maison, which fits these developments in European society like a glove. Households seem to have been a central ordering principle in this case. In a peasant society, at any rate, the primary social orientation was to one’s house, not to one’s relatives. This was an essential distinguishing feature vis-a-vis societies oriented toward descent; these kinship patterns were located around the periphery of Europe, but in the main they lay beyond Europe’s borders. Belonging to a household was clearly a basic building block of the bipartite estate in the Frankish Empire. On the one hand, there was the villa, the lord’s manor, or the steward’s manor, with its resident labor force, the members of which were not tied to one another by kinship; on the other hand, there were the farms of the servi casati, that is, of the unfree laborers and their dwellings, as well as the coloni who were boind to the soil and therefore to a house. Together they formed the familia, an overarching household embracing several households…. Affiliation with a farmstead of this kind was socially determinative, not the affiliation to a group through kinship.

update: see also jayman’s IQ Ceilings?

previously: medieval manoralism and genetic relatedness and family types and the evolution of behavioral traits and assortative mating and the selection for high iq in (some) medieval european populations?

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