I'm a sucker for broad historical books that attempt to explain why cultures differ, especially with regard to the Great Divergence, where Western Europe separated from the rest of the world around 1500 AD and came to dominate/colonize the rest of the world. Joe Henrich's book "The WEIRDest People in the World: How the West Became Psychologically Peculiar and Particularly Prosperous" offers up the best argument I have encountered so far and is one the most fascinating books I have ever read.
Put simply, Henrich's thesis is that the set of beliefs regarding marriage and the family within the medieval Catholic Church led to the demolition of Europe's kin-based network of clans that had previously ruled Europe. This shift began to alter European psychology in ways that promoted the growth of new institutions and voluntary associations like guilds, universities, monasteries, and cities with impersonal markets. These new institutions in turn created a feedback loop, further altering European psychology to make it increasing WEIRD (Western/Educated/Industrialized/Rich/Democratic) and paving the way for novel developments in government, religion, law, and economics that would propel Europe towards unrivaled prosperity.
The key principle Henrich builds his argument on is that human beings vary psychologically based on their environment. The human brain has wide plasticity that allows us to learn norms that are based on our environmental context and surrounding culture. These norms then compete against one another via intergroup competition where the most advantageous norms for group cohesion win out as less cohesive groups are wiped out or absorbed into the more successful one. These cultural norms in turn co-evolve along with our genes that can alter our psychology and even biology in profound ways. Henrich's previous book "The Secret of Success" explains this in depth by citing examples such as how cultures harnessing fire to cook led to the human jaw and digestive track gradually evolving to be smaller since cooked meals were easier to digest. Culture drove biological evolution.
Henrich's work is full of studies and data, much of which he has collected himself, which documents how WEIRD psychology differs from much of the world. WEIRD psychology is characterized by individualism, self-focus, analytical thinking, guilt rather than shame based motivations, less conformity, impersonal morality, patience, and less zero sum thinking. In contract, people from kin based societies are far less individualistic, put conformity to their clan above general rules, fear outsiders, and are more motivated by shame imposed by their community rather than individualized feelings of guilt. These differing psychological profiles show up all over today and can even be linked to different rates of parking violations by UN representatives who come from kin based societies. Henrich marshals a massive amount of data to show that extent of kin based institutions within a society shapes psychology drastically. The rates of cousin marriage (the best proxy for measuring kinship in a society) in a country allows Henrich to predict how accepting of representative democracy or economically productive a society is today.
Henrich goes through extensive historical examples to show how the medieval Church’s marriage and family policy led to the rise of WEIRD psychology. This new psychology fueled the rise of voluntary associations, impersonal markets, urbanization, representative democracy, individual legal rights, and economic growth. The more exposure a society had to the Marriage and Family Policy (MFP) of the Church the less kinship based institutions survived and the WEIRDer it became psychologically. Perhaps surprisingly for a secular thinker like Henrich, he concludes that far from being a “Dark Age”, the medieval era set the stage for the rise of the modern world. On the Enlightenment, Henrich downplays the Pinkerian notion of the triumph of reason over religious superstition. Instead, Enlightenment thinkers built on work done by “their intellectual forebearers in the Church.” Henrich writes, “The bottom line is that Enlightenment thinkers didn’t suddenly crack the combination of Pandora’s box and take out the snuff box of reason and the rum bottle of rationality from which the modern world was then conceived. Instead, they were part of a long, cumulative cultural evolutionary process that had been shaping how European populations perceived, thought, reasoned, and related to each other stretching back into Late Antiquity. They were just the intellectuals and writers on the scene when WEIRDer ways of thinking finally trickled up to some of the last holdouts in Europe, the nobility” (429). Henrich refers to this WEIRDer way of thinking (individualism/analytic thinking/impersonal prosociality) as “psychological dark matter” that had long slowly manifested across Europe in the institutions that would shape the modern world.
Overall, Henrich’s argument is very convincing and has impressive explanatory power. Books like “Why Nations Fail” point to the role of inclusive institutions in the success of the West, but they struggle to explain why these distinct institutions arose in the first place. Henrich has no such problem. He has chapters devoted to developments in law, science, markets, and innovation that trace how Europeans new ways of thinking and their unique institutions drove political and economic development. These chapters contain speculation and anything as complex as historical causation is never going to be a slam-dunk. However, the sheer weight of his argument gradually accumulates and becomes quite persuasive.
However, I did find Henrich’s repeated emphasis that the Church “stumbled upon”(471) it’s marriage and family policy as some kind of “accidental genius of Western Christianity” to be somewhat odd. Henrich concedes that the church came up with the MFP “for a complex set of historical reasons” (179) and affirms that he is more interested with the downstream impacts of the MFP on European psychology and history. At times, he seems to suggest that the Church’s motives were merely a cynical scam to monopolize inheritances and Henrich mostly ignores Christian theology throughout the book. In the footnotes, Henrich mentions, “The motivations of Church leaders aren’t paramount. Church leaders, just like the leaders of the Isis cult or Nestorian Christianity, may have developed their beliefs, prohibitions, and prescriptions based on deep religious convictions; or, some may have been playing political games for their own enrichment. It doesn’t matter” (539). As a believer in human depravity, I’d say it’s always some combination of the two, but I’m surprised that Henrich does not have more interest in the actual ideological motivations behind Church policies. After all, he spent 600 pages explaining how these policies led to the rise of the modern! For some, like Tufts Professor, Daniel Dennett, who reviewed the book in the New York Times the motivations certainly matter. As an arch atheist and anti-Christian polemicist, Dennett affirms, “The genius was accidental, according to Henrich, because the church authorities who laid down the laws had little or no insight into what they were setting in motion, aside from noticing that by weakening the traditional bonds of kinship, the church got rich fast.” I am not sure if Henrich would agree with Dennett’s synopsis. Henrich’s work is more nuanced and does not argue that every Church leader was a mercenary.
Still, Henrich is very uncomfortable when it comes to religious motivations. Henrich has an entire chapter on WEIRD monogamy that clearly shows the Church’s deep religious convictions fueled major components of the Church’s marriage and family policy. Henrich describes how the Church worked to end sexual slavery, polygamy, and instill an equal expectation of fidelity for both men and women. This combination subsequently led to lower testosterone levels in Christian Europe, as “the Church, through the institution of monogamous marriage, reached down and grabbed men by the testicles” (273). As a result, this “peculiar version of monogamous marriage, unintentionally created an environment that gradually domesticated men, making many of us less competitive, impulsive, and risk-prone while at the same favoring positive-sum perceptions of the world and greater willingness to team up with strangers. Ceteris paribus, this should result in more harmonious organizations, less crime, and fewer social disruptions” (281). The word “unintentionally” is doing a whole lot of work here. Monogamous commitment and social equality among men and women in marriage were fundamental components of the early Church’s message and come directly out of Christian scripture. The classical historian Tom Holland writes in his book “Dominion” regarding Christian marriage that “the insistence of scripture that a man and a woman, whenever they took to the marital bed, were joined as Christ and his Church were joined, becoming one flesh, gave to both a rare dignity…Here, by the standards of the age into which Christianity had been born, was an obligation that demanded an almost heroic degree of self-denial” (282). Henrich agrees that this new conception of monogamous marriage was “neither ‘natural’ nor ‘normal’ for human societies – and runs directly counter to the strong inclinations of high-status or elite men-it nevertheless can give religious groups and societies and advantage in intergroup competition” (281). Henrich expounds on the impact of this change, “Church monogamy also meant that men and women of similar ages usually married adults, by mutual consent, and potentially without the blessing of their parents. Of course, the greater parity of modern gender roles was a long way off in the Early Middle Ages but monogamous marriage had started to close the gap” (282). Tom Holland also points to this seismic shift. “The Church, in its determination to place married couples, and not ambitious patriarchs, at the heart of a properly Christian society had tamed the instinct of grasping dynasts to pair off cousins with cousins. Only relationships sanction by canons were classified as legitimate. No families were permitted to be joined in marriage except for those licensed by the Church: ‘in-laws’. The hold of clans, as a result, had begun to slip. Ties between kin had progressively weakened. Households had shrunk. The fabric of Christendom had come to possess a thoroughly distinctive weave” (285). While Holland recognizes the religious convictions that drove this revolutionary process, Henrich either sees random chance or punts on the question of motivation altogether.
Henrich filters everything through his approach to cultural evolution and intergroup competition. Countless religions all compete against one another and revolve around myths. The Christian myth happened to work best in competition with other groups in the religious cauldron that was the Mediterranean world of antiquity. After winning out, Christian Church policies slowly transformed European psychology, fueling its unrivaled prosperity. Henrich describes how Christian influences are so profound that “even nonreligious Americans (like me) seem a bit ‘Protestant’” (421). In the cosmic sense for a materialist like Henrich, everything is accidental and organizations “stumble upon” their beliefs since cultural evolution runs everything in the background, favoring scenarios where “people’s explicit theories about their own institutions are generally post hoc and often wrong” (86). While I think Henrich has a point about how banning cousin marriage to an extreme degree in the medieval church had profound consequences, some of which were surely unanticipated (i.e., medieval popes weren’t actively plotting how to fuel the Industrial Age), I think he fails to recognize how much the Church’s policy on things like divorce, equality between the sexes, and monogamy are at the heart of Christian religious conviction. Implementing them in Europe was not accidental. Taming men’s exploitive sexual appetites was not an unintended consequence, but the goal from the start. Great harmony, self-regulation and a unifying Christian identity line up with the gifts of the Spirit. Maybe the Church was on to something.
For Henrich, I think the failure to consider these ideas is a blind spot in his secular perspective. Perhaps establishing the motivations behind the Church’s marriage and family policy does not matter for his argument, but I suspect that he does care. How can you not be curious about the motivations of men and women who remade the world and ultimately paved the path to modern civilization? The motivations certainly matter to someone like Daniel Dennett, with his cynical takeaway and convenient dismissal of the West’s Christian heritage as nothing more than an accidental result of policies masterminded by greedy priests. If anything, by properly rooting the Church’s hugely influential Marriage and Family Policy in history, readers will better understand history. I suspect that Henrich is probably uncomfortable with the idea that Christian theology is the basis of modern WEIRD culture. His research has pointed him to the unique and decisive role of the Church, and his analysis fits nicely with many other historians who have pointed to the role of Christianity in the rise of the West. However, as a secular thinker, Henrich is far more comfortable in the world of intergroup competition than in the minds of medieval churchmen, and I think his analysis about the motivations behind the Church’s Marriage and Family Policy suffers as a result.