Medieval Catholic Church's Marriage and Family Policies Shaped the Psychology of Westerners Living Today, Study Suggests

In the European Middle Ages (5th to the 15th centuries) the Western Christian Church had a significant influence on marriage and family structures. So influential, in fact, that some of the beliefs and behaviors of those living in Western cultures around the world today can be traced back to the church's marriage and family policies during this period, according to an international team of researchers.

Recent studies have shown that there is substantial variation in the psychological beliefs and behaviors of people living in different cultures around the world. In particular, Western Europeans and their cultural descendants in North America and Oceania display psychological traits that are "particularly unusual" compared to the rest of the world, the authors of a study published in the journal Science said.

"Our paper really begins with the recognition that substantial global variation exists in many important dimensions of psychology," Joseph Henrich, one of the authors of the study from George Mason University, told reporters in a teleconference. "This first became clear to me when I was working on a paper called The Weirdest People in the World, which my coauthors and I published in 2010."

"In our review of the available data from psychology, economics and related fields we showed that not only is there large variation in many important aspects of psychology, but the most commonly studied populations, were particularly psychologically unusual. We dubbed these populations as 'WEIRD,' an acronym that stands for Western, Educated, Industrialized, Rich and Democratic."

People from societies characterized as "WEIRD" tend to be more individualistic, independent, analytically-minded and trustful of strangers (a trait known as "impersonal prosociality,") while also displaying less conformity, obedience, solidarity and in-group loyalty.

These trends have been well-documented by psychologists, however, the cultural and historical evolution of these variations is not so well understood.

"As we brought that [2010 paper] to fruition, I turned to focus on ways to understand and explain the patterns of variation we had uncovered," Henrich said. "At the time, I was influenced by my ongoing anthropological fieldwork in one of the outer islands in Fiji, where social life is still governed by strong norms of kinship, which endow everyone with a set of responsibilities, obligations and privileges. The centrality of kinship in people's daily lives was striking."

"While pondering this, I read a book written by the anthropologist Jack Goody," he said. "Goody, who had done extensive fieldwork in Africa, argued that the Western Christian Church, the branch of Christianity that eventually evolved into the Roman Catholic Church, had transformed European society from the grassroots by dismantling its intensive kin-based institutions—it's clans, kindreds and extended families—eventually leaving much of Europe with monogamous nuclear families. Monogamous nuclear families are vanishingly rare outside of Western Europe."

In this context, the team wondered whether it was plausible that kinship systems, or kin-based institutions, might have a big effect on people's psychology.

"People's minds might adapt to the demands and incentives created by different kin-based institutions," Henrich said. "Specifically, it seemed clear from anthropological ethnography, that some kin-based institutions, such as patrilineal clans, demand and incentivize strong in-group loyalty, high levels of conformity, a sharp distinction between in-groups and outgroups, and a sense of self that merges with one's kinfolk rather than atomistically distinguishing the individual. In this view, religion could potentially shape people's psychology through its impact on marriage and the family."

In the latest study, a team led by Jonathan Schultz from George Mason University decided to test these ideas. They examined how the Western Catholic Church had an impact on psychological variation around the world—via its influence on marriage and family structures during the Middle Ages—by analyzing a wealth of anthropological, psychological and historical research.

By examining this research, the authors concluded that psychological traits like greater individualism, lower conformity and increased trust in strangers can in part be traced back to the Western Church's marriage and family policies in the Middle Ages.

Essentially, the authors argue that the Western Church's marriage and family policies helped to break apart strong, cohesive kin-based family networks—and that this process subsequently had an impact on psychology in Western cultures.

"Specifically, we propose that the Western Church's transformation of European kinship, by promoting small, nuclear households, weak family ties, and residential mobility, fostered greater individualism, less conformity, and more impersonal prosociality," the authors wrote in the study.

crucifix, bible
Stock photo: A Christian crucifix resting on an open bible. iStock

"By combining data on 24 psychological outcomes with historical measures of both Church exposure and kinship, we find support for these ideas in a comprehensive array of analyses across countries, among European regions, and among individuals from different cultural backgrounds," they said.

According to the authors, the latest study casts light on how cultural trends that took place hundreds of years ago can have an impact on the psychology of people living today.

"Our findings have big implications for both psychology and economics," Henrich told Newsweek. "We show that textbook findings within these disciplines, such as peer conformity in psychology or peer punishment in economics, have been substantially shaped by historical and cultural evolutionary processes. To understand global psychological variation, we need to develop the field of cultural evolutionary psychology and to integrate these historical insights and data."

Michele Gelfand, a psychologist from the University of Maryland who was not involved in the study, said that understanding human diversity is not only critical for the advancement of science, but also for bridging cultural divides.

"Illuminating the ways in which cultures vary—and why they have evolved in different ways given certain socio-environmental forces—can help us to empathize with those who are different," she wrote in an article about the latest research, which was also published in Science. "By documenting how a very specific religious agenda in late antiquity may have had far-reaching effects on the development of cultural differences between the West and the rest of the world, Schulz et al. help us to decipher part of the puzzle of human diversity."