Europe, particularly northwest Europe, was pushed forward by an expanding market economy, Peter Frost explains, in the fourteenth century, when England and Holland embarked on sustained economic growth:
That expansion was driven, in turn, by a population that tended toward individualism and “impersonal sociality.” For at least the past millennium, Europeans were behaviorally distinct north and west of a line running approximately from Trieste to St. Petersburg:
Almost everyone was single for at least part of adulthood, and many stayed single their entire lives.
Children usually left the nuclear family to form new households, and many individuals circulated among unrelated households, typically young people sent out as servants.
People were more individualistic, less loyal to kin, and more willing to trust strangers (Frost 2017; Frost 2020; Hajnal, 1965; Hartman, 2004; Hbd*chick 2014; ICA, 2020; MacDonald 2019; Seccombe, 1992, p. 94-95, 150-153, 184-190).
According to Schulz et al. (2019), the above behavioral pattern was created by the Western branch of Christianity, particularly through its decision in the ninth century to broaden the ban on cousin marriages to any couple who shared a common ancestor seven generations previously. That ban, they argued, had the effect of creating the Western European pattern of late marriage, frequent celibacy, and nuclear households. That pattern, in turn, encouraged individualism and impersonal sociality.
Schulz et al., however, ignore two points. First, the broadening of the cousin marriage ban resulted from a decision to abandon the Roman method of calculating degrees of kinship, whereby first cousins were considered to be fourth degree. The new method, of Germanic origin, made them second degree, thereby doubling the number of forbidden marriage partners (McCann, 2010, pp. 57-58). In sum, the ban was Church-enforced but of pagan origin.
Second, when the cousin marriage ban was broadened in the ninth century, Western Europe already had high rates of late marriage, celibacy, and nuclear households. This has been shown at two locations in ninth-century France: the estates of the Abbey of St Germain-des-Prés near Paris, where about 16.3% of all adults were unmarried, and Villeneuve-Saint-Georges, where the figure was 11.5%. At both locations, households were small and nuclear (Hallam 1985, p. 56). A ninth-century survey of the Church of St Victor of Marseille shows both men and women marrying in their mid to late twenties (Seccombe 1992, p. 94). Further back, in the first century, the Roman historian Tacitus wrote about the Germanic tribes, “Late comes love to the young men, and their first manhood is not enfeebled; nor for the girls is there any hot-house forcing; they pass their youth in the same way as the boys” (Tacitus, Germania 20, 1970).
It seems more correct to say that Western Christianity promoted individualism and impersonal sociality because it had assimilated a pre-existing pattern of weak kinship, late marriage, and openness to non-kin. A fusion took place between the Christian faith and the pre-Christian values of northwest Europe (Russell 1994). With the loss of North Africa and Spain to the Muslims, and the rise of the Frankish-dominated Carolingian Empire, Western Christianity saw its ideological center of gravity move northward and westward.
From the eleventh century onward, the Western Church also strove to pacify social relations. Both Church and State came around to the view that the wicked should be punished so that the good may live in peace. Courts imposed the death penalty more and more often and, by the late Middle Ages, were condemning to death between 0.5 and 1.0% of all men of each generation, with perhaps just as many offenders dying at the scene of the crime or in prison while awaiting trial. The homicide rate plummeted from the fourteenth century to the twentieth, with the result that the pool of violent men dried up. Most murders would now occur under conditions of jealousy, intoxication, or extreme stress. (Frost and Harpending 2015).
Those three causes — individualism, impersonal sociality, and a pacified environment — allowed the market economy to grow beyond its former limits (Frost 2020; Macfarlane 1978; Weber 1930). The first two causes had long been around in northwest Europe, being what we may call “pre-adaptations” to the market economy. It was the third one, the pacification of social relations, that sparked the economic takeoff of the fourteenth century. The “market” was no longer a marketplace—an isolated point in space and time. It was now a means to carry out transactions wherever and whenever. It could thus spread farther and farther beyond the marketplace, replacing older forms of exchange and ultimately replacing kinship as the main organizing principle of society.
