WEIRD Origins

Image result for catholic church medieval
“Thou art weird.”
Anthropologist and cultural psychologist Joseph Henrich has defined our peculiar subset of the world population as WEIRD: Western, Educated, Industrialized, Rich, Democratic. How did this psychological variation arise? A new working paper offers a very interesting answer:

A growing body of research suggests that populations around the globe vary substantially along several important psychological dimensions, and that people from societies characterized as Western, Educated, Industrialized, Rich and Democratic (WEIRD) are particularly unusual (1–6). Often at the extremes of global distributions, people from WEIRD populations tend to be more individualistic, independent, analytically-minded and impersonally prosocial (e.g., trusting strangers) while revealing less conformity, obedience, in-group loyalty and nepotism (3, 5–13). While these patterns are now well documented, efforts to explain this variation from a cultural evolutionary and historical perspective have just begun (13–20). Here, we develop and test a cultural evolutionary theory that aims to explain a substantial portion of this psychological variation, both within and across nations. Not only does our approach contribute to explaining global variation and address why WEIRD societies so often occupy the tail ends of global distributions, but it also helps explain the psychological variation within Europe—among countries, across regions within countries and between individuals with different cultural backgrounds within the same country and region.

Our approach integrates three insights. The first, drawing on anthropology, reveals that the institutions built around kinship and marriage vary greatly across societies (21–23) and that much of this variation developed as societies scaled up in size and complexity, especially after the origins of food production 12,000 years ago (22, 24–29). In forging the tightly-knit communities needed to defend agricultural fields and pastures, cultural evolution gradually wove together social norms governing marriage, post-marital residence and in-group identity (descent), leading to a diversity of kin-based institutions, including the organizational forms known as clans, lineages and kindreds (21, 27, 30). The second insight, based on work in psychology, is that people’s motivations, emotions, perceptions, thinking styles and other aspects of cognition are heavily influenced by the social norms, social networks, technologies and linguistic worlds they encounter while growing up (31–38). In particular, with intensive kin-based institutions, people’s psychological processes adapt to the collectivistic demands and the dense social networks that they interweave (39–43). Intensive kinship norms reward greater conformity, obedience, holistic/relational awareness and in-group loyalty but discourage individualism, independence and analytical thinking (41, 44). Since the sociality of intensive kinship is based on people’s interpersonal embeddedness, adapting to these institutions tends to reduce people’s inclinations towards impartiality, universal (non-relational) moral principles and impersonal trust, fairness and cooperation. Finally, based on historical evidence, the third insight suggests that the branch of Western Christianity that eventually evolved into the Roman Catholic Church—hereafter, ‘the Western Church’ or simply ‘the Church’—systematically undermined the intensive kin-based institutions of Europe during the Middle Ages (45–52). The Church’s marriage policies and prohibitions, which we will call the Marriage and Family Program (MFP), meant that by 1500 CE, and likely centuries earlier in some regions, Europe lacked strong kin-based institutions, and was instead dominated by relatively weak, independent and isolated nuclear or stem families (49–51, 53–56). This made people exposed to Western Christendom rather unlike nearly all other populations.

Integrating these insights, we propose that the spread of the Church, specifically through its transformation of kinship and marriage, was a key factor behind a cultural shift towards a WEIRDer psychology in Europe. This shift eventually fostered the creation of new formal institutions, including representative governments, individual rights, commercial law and impersonal markets (17, 57). This theory predicts that (1) societies with less intensive kin-based institutions should have a WEIRDer psychology and (2) historical exposure to the Church’s MFP should predict both less intensive kin-based institutions and, as a consequence, a WEIRDer psychology.

To illuminate these relationships for diverse populations, we (1) developed measures of the intensity of kin-based institutions, (2) created historical databases to estimate the exposure of populations to the Church (along with the MFP) and (3) compiled 20 different psychological outcomes, including laboratory experiments, validated scales, survey questions and ecologically-valid observational data. We examine the predicted relationships from three complementary perspectives. Across countries, we can observe the broadest range of variation in the largest number of psychological outcomes. Across regions, we can track the historical Church as it lumbered across Europe and detect its footprints on the psychological patterns and marital arrangements of modern Europeans. Finally, by comparing second-generation immigrants in Europe based on their links to the kin-based institutions of their ancestral communities around the world, we eliminate many alternative hypotheses for the relationships we’ve illuminated.

Check it out.