Lower cousin marriage rates predict higher civicness and more inclusive institutions today

An interesting paper on a long running dispute - the sources of economic and political development. Some argue for an overwhelming role of factors such as geography, institutional strength, the nature of the institutions, culture, population IQ, religion, path dependency, technology, folkways, marital pairing and mating traditions, market economy, degree of freedom, etc. Some (and I number myself among these) argue that is a mix of all those things, attaching different weights to each.

From The Catholic Church, Kin Networks, And Institutional Development by Jonathan F. Schulz. From the Abstract:

Political institutions vary widely around the world, yet the origin of this variation is not well understood. This study tests the hypothesis that the Catholic Church’s medieval marriage policies dissolved extended kin networks and thereby fostered inclusive institutions. In a difference-in-difference setting, I demonstrate that exposure to the Church predicts the formation of inclusive, self-governed commune cities before the year 1500CE. Moreover, within medieval Christian Europe, stricter regional and temporal cousin marriage prohibitions are likewise positively associated with communes. Strengthening this finding, I show that longer Church exposure predicts lower cousin marriage rates; in turn, lower cousin marriage rates predict higher civicness and more inclusive institutions today. These associations hold at the regional, ethnicity and country level. Twentieth-century cousin marriage rates explain more than 50 percent of variation in democracy across countries today.

I think one of the West's great accomplishments, through the Age of Enlightenment, has been to model a transition towards viewing people as individuals with God given rights rather viewing the world as a set of zero-sum competing identity factions. Once people see themselves as having many identities, the mechanisms for affirmingly interacting with others across traditional barriers such as clan, tribe, gender, religion, class, etc. dramatically improves information flow, productivity, and capacity to accept others.

I fear the profound ignorance of the social justice, intersectional, critical theory Jacobins is facilitating the return of the primitive with their unrelenting focus on building barriers between individuals - barriers based on race, religion, class, gender, etc.

This research provides some evidence about the importance of removing barriers based on identity rather than building them up.

UPDATE: Related, The origins of WEIRD psychology by Tyler Cowen.

Recent research not only confirms the existence of substantial psychological variation around the globe but also highlights the peculiarity of populations that are Western, Educated, Industrialized, Rich and Democratic (WEIRD). We propose that much of this variation arose as people psychologically adapted to differing kin-based institutions—the set of social norms governing descent, marriage, residence and related domains. We further propose that part of the variation in these institutions arose historically from the Catholic Church’s marriage and family policies, which contributed to the dissolution of Europe’s traditional kin-based institutions, leading eventually to the predominance of nuclear families and impersonal institutions. By combining data on 20 psychological outcomes with historical measures of both kinship and Church exposure, we find support for these ideas in a comprehensive array of analyses across countries, among European regions and between individuals with different cultural backgrounds.

ALSO: Cousin Marriage Conundrum by Steve Sailer.