The medieval Church’s ban on incest was decisive in the growth of individualism in the West, a new study has suggested.

Driving the news

In a study published Friday in the journal Science, a group of economics and evolutionary biology researchers from George Mason University and Harvard University in the US sought to discover why populations characterised as Western, Educated, Industrialized, Rich, and Democratic (WEIRD) “are particularly unusual” in the global context.

“Western Europeans and their cultural descendants in North America and Australia tend to be more individualistic, independent, analytically minded, and impersonally prosocial (e.g., trusting of strangers) while revealing less conformity, obedience, in-group loyalty, and nepotism”, the researchers wrote.

While psychological testing has confirmed the prevalence of these traits in Western societies, “efforts to explain this variation from a cultural-evolutionary and historical perspective have just begun”, the scholars said.

To fill that gap, the researchers considered “how religions have evolved in ways that shape people’s institutions, social practices, economic outcomes, and psychology”.


Father WALL-E? Say hello to robot priests

Go deeper

To explain the WEIRD variation, the George Mason and Harvard scholars proposed a theory based on three key insights.

First, that cousin marriage was an integral part of the pre-modern kin-based institutions that evolved to promote values such as “in-group loyalty, conformity, obedience to elders, and solidarity”.

Second, that those kin-based institutions incentivised “the cultivation of greater conformity, obedience, nepotism, deference to elders, holistic-relational awareness, and in-group loyalty”, but that much to the expense of “impartiality, universal (nonrelational) moral principles, and impersonal trust, fairness, and cooperation”.

The researchers’ third insight was that the Church, beginning in Late Antiquity, “systematically undermined Europe’s intensive kin-based institutions through a combination of religious prohibitions and prescriptions”.

“By the Early Middle Ages, the Church had become obsessed with incest and began to expand the circle of forbidden relatives, eventually including not only distant cousins but also step-relatives, in-laws, and spiritual kin”, the researchers wrote.

That was at the same time, the scholars added, that the Church promoted marriage “by choice” and encouraged newlyweds to set up independent households, as well as putting an end to adoption, remarriage, and all forms of polygamous marriage and concubinage.

The result was that, by the beginning of the sixteenth century, “much of Europe was characterized by a virtually unique configuration of weak (nonintensive) kinship marked by monogamous nuclear households, bilateral descent, late marriage, and neolocal residence [new households]”, the researchers wrote.

Don’t miss:

This is what religion will look like in the future

Why it matters

In short, the researchers’ theory was that “populations with a longer exposure to the medieval Western Church or less-intensive kin-based institutions will be less conforming but more individualistic and impersonally prosocial”.

To test the hypothesis, the scholars calculated the spread of influence of the Western Church in all the countries of the world – and in 440 regions of Europe in detail – as well as the spread of the Eastern Church, historically less concerned about degrees of kinship in marriage.

The researchers then crossed the data with Vatican records of cousin-cousin marriages, and with conclusions from previous tests on different psychological characteristics and behaviours across countries and regions.

Their results showed a clear correlation between historical exposure to the Catholic Western Church, the decline of kinship structures, and the growth of traits such as independence, individualism, analytical thinking and fairness and trust with strangers.

Next on Novena:

Europeans think religion a source more of conflict than of peace, survey says