Here’s an ethical dilemma for you to mull over:

If you found yourself boxed into this awkward situation, what right would you say your friend has in expecting you to protect him?

If you would refuse to testify and protect your friend, you are probably pretty WEIRD. That is, you most likely grew up in a country which is Western, Educated, Industrialised, Rich and Democratic (lucky you).

If you’re WEIRD like me, you may be surprised to learn that of the corporate managers across the world who were presented with this ethical dilemma, a sizable proportion outside of Western countries said that they would lie under oath to protect their friend.

Whether you’re aware of it or not, being WEIRD makes you an outlier psychologically among the world’s diverse inhabitants of humans.

Compared to the rest of humanity, we Westerners are highly individualistic, self-centred, control oriented, and analytical. We tend to focus on ourselves— our unique characteristics, our achievements and our ambitions— rather than on our relationships with our family and friends.

Despite our rugged individualism and benign levels of narcissism, we WEIRDos tend to treat people fairly, and are unusually trusting of strangers. Similarly, we think nepotism and cronyism is wrong, and we forgo numerous opportunities to further our friend’s and family’s interests.

This raises the million-dollar question: how did we Westerners become so peculiar?

The Weirdest People in the World

In his new book The Weirdest People in the World, American anthropologist Joseph Henrich not only explores the psychology of ‘WEIRD’ people, but also excavates the origins of the modern world (a tall order, I know).

Joseph Henrich is Professor and Chair of Harvard University’s department of Evolutionary Biology, and is a champion of interdisciplinary science (Henrich initially trained as an aerospace engineer, and has held professorships in psychology, economics, and evolutionary biology). Henrich’s first popular science book, The Secret of Our Success, was an instant classic in the social sciences, where he convincingly made the case that culture is now the dominant force driving human evolution.

Ten years ago, Joe and his colleagues Steven Heine and Ara Norenzayan penned a scientific paper with the same title of his new book. Their paper served as reality check for psychologists (ironic indeed), where Henrich and his colleagues lamented the lack of diversity among psychological studies. To elaborate, they criticised psychologists for making sweeping generalisations about human psychology, when their research actually narrowly focused on a thin slice of humanity— WEIRD people (more specifically, WEIRD university students). Having trawled through the literature, they discovered that over 96% of participants in psychological experiments were WEIRD.

Although this publication made waves across the world of behavioural science, Henrich admits that he wasn’t entirely satisfied with their paper. “I’ve always found it unsatisfying, because it doesn’t explain anything. How can we account for all this psychological variation?”. In the aftermath of their publication, explaining the existence of these broad psychological differences monopolised Henrich’s thinking.

So, what does explain Westerners’ unique psychological profile? The surprising conclusion that Henrich and his collaborators have reached is that these psychological differences can be traced back to the Catholic Church.

The Holy Scriptures

In The Weirdest People in the World, Henrich argues that around 1,500 years ago, the medieval Catholic Church (the branch of Christianity that would become the Western Church) began promoting a particular set of prohibitions and prescriptions about marriage and the family, which inadvertently altered people’s psychology.

It’s well known that outlawing polygyny— a form of polygamy where a man has multiple wives— helps keep the worst aspects of our nature at bay (monogamy insures against armies of incels inciting violent uprisings). However, counterintuitively, Henrich argues one of the most impactful of the Church’s prohibitions was the banning of cousin marriage. Why was this practice so impactful? Because the banning of cousin marriage (along with the Church’s overzealous imposition of incest-taboos more generally) effectively dissolved the densely interconnected clans and kindreds that roamed Western Europe. Consequently, these clans were shredded into small and independent nuclear families.

Why would the nuclear family structure fundamentally alter our psychology? Henrich’s central claim is that the Catholic Church’s ‘Marriage and Family Plan’ effectively dismantled tribes and clans in Western Europe, which relied heavily on arranged marriages to cement political ties (think of the prolonged political wrangling that takes place in the make-believe world of Game of Thrones— let alone all the incest). These social arrangements forced people to venture outside of their closed-knit communities to find their lovers to be, rather than fulfilling their obligations and duties to their extended families (which were largely assigned at birth). This incentivised people to build their own social circles and to cultivate traits that other people would find valuable and attractive, as they had to compete in the market of affection.

The impact of these practices on Westerners’ lives cannot be overstated. Henrich spells out what this meant for day-to-day living:

In most WEIRD societies, you can’t marry your stepson, take multiple spouses, or arrange the marriage of your teenage daughter to your business partner. Similarly, you could tell your son that he must move into your house after he gets married, but he and his wife may have other ideas when you have little leverage. You are compelled by custom in law to build relationships by other means and to depend on impersonal markets, governments, and other formal institutions (e.g. to provide safety nets for injuries, disasters, and unemployment).

Henrich argues that these curbs enforced by the Catholic Church got the ball of individualism rolling, which subsequently sparked a chain of large-scale societal changes— sprouting the seeds of impartial institutions such as guilds, universities and businesses. By the high Middle Ages, catalysed by the Catholic Church’s social cauldron, Henrich argues that these newly formed WEIRD ways of thinking and feeling propelled novel forms of government, whilst also accelerating innovation and the emergence of science. These self-reinforcing forces thus fuelled the rise of capitalism and liberal democracy.

If Henrich’s thesis is correct, then the Catholic Church ironically created the fertile conditions necessary for the scientific Enlightenment. However, Henrich stresses that the rise of Western societies over the last 500 years was not inevitable, nor that anyone would necessarily have predicted it beforehand. To put it bluntly, the idea that a bunch of barbarians in Europe would later amass great wealth and expand across all corners of the globe would have been inconceivable.  

As stated by Henrich:

If a team of alien anthropologists had surveyed humanity from orbit in 1000 CE, or even 1200 CE, they would never have guessed that European populations would dominate the globe during the second half of the Millennium. Instead, they would probably have bet on China or the Islamic world.

Henrich continues:

What these aliens would have missed from their orbital perch was the quiet fermentation of a new psychology during the Middle Ages in some European communities. This evolving proto-WEIRD psychology gradually laid the groundwork for the rise of impersonal markets, urbanisation, constitutional governments, democratic politics, individualistic religions, scientific societies, and relentless innovation. In short, these psychological shifts fertilise the soil for the seeds of the modern world.

The Weirdest People in the World is peppered with evidence of the lingering effects of Catholicism and Protestantism on Western minds. For example, Henrich shows that when a country received their first ‘dose’ of the Catholic Church’s family plan predicts how much their inhabitants currently respect tradition, trust strangers, and how ‘tight’ they are culturally. Remarkably, when countries were first exposed to the Western Church also predicts their rates of voluntary blood donations, and also the amount of unpaid parking tickets that UN Diplomats clock up during their time in New York City.

One knee jerk criticism of Henrich’s theory is that the prevalence of Catholicism varies across the Western world, and also within Western countries. However, this is actually one of the most convincing pieces of evidence in favour of his thesis. For example, Henrich points out that provinces in Italy which have the lowest rates of cousin marriage (which serves as a proxy for Catholicism) donate much more blood on a voluntary basis.

Henrich stacks several layers of evidence to make his arguments watertight, ruling out alternative explanations for the impact of the Western Church on people’s sense of trust, fairness and ‘impersonal prosociality’ (Henrich controls for factors including wealth, ecology, climate, and geography). Evidently, Henrich knows he’s going to be dragged into a fight— and he has covered all bases accordingly.

Rewriting history

With the passing of time, it’s inevitable that scholars will poke holes in Henrich’s writings (appreciating the inter-disciplinary nature of Henrich’s research). For example, evolutionary anthropologist William Buckner has questioned Henrich’s portrayal of polygyny in traditional societies, raising doubts regarding how much ‘choice’ women really have in such arrangements.

One scathing review of The Weirdest People in the World implied that Henrich has trivialised the scale of suffering inflicted by colonialism. However, this criticism doesn’t seem fair. Henrich clearly acknowledges the “very real and pervasive horrors of slavery, racism, plunder and genocide”. Rather, henrich explores the trajectories cultural evolution has taken and its enduring impact on our psychology, long after such horrors took place.

Personally, I’m still trying to wrap my head around how Stoicism fits into Henrich’s grand narrative. What do I mean? Stoicism is a philosophy of personal ethics which flourished in Ancient Greece and Rome, and the Stoics’ meditations on impartial justice and rational thinking strikes me as pretty WEIRD (from a modern interpretation of the philosophy at least). Yet, Stoicism actually predates Christianity by at least 300 years.

These points aside, I’m confident the critiques that’ll continue to come Henrich’s way will resemble minor quibbles, rather than challenges that threaten to tear down the walls of the theoretical edifice.

In summary, The Weirdest People in the World is dazzling in its breadth, along with its broad sweeping implications. When I reviewed Henrich’s The Secret of Our Success, I described it as a “a tour-de-force and a significant advancement of social science”. I’d confidently state that Henrich has once again raised the bar; this book is a landmark in social thought.

By chasing the ghosts of the medieval Catholic Church, Henrich has essentially rewritten the story of modern history. Indeed, Henrich illuminates the value of approaching history from a cultural-evolutionary perspective, and builds on recent efforts to make history a more quantitative and scientific discipline. To quote Henrich; “The cultural evolution of psychology is the dark matter that flows behind the scenes throughout history.”

Similarly, The Weirdest People in the World may well transform the field of psychology. Henrich and his colleagues began their intellectual journey by raising concerns about the overreliance on Western university students in psychology studies, and their efforts continue to influence the field. However, another lasting impact of Henrich’s contributions may be for psychology to be transformed into a historical science.  

Henrich’s research reveals the counterintuitive impacts of cultural practices enacted hundreds of years ago on our psychology (and even on our physiology). These are timeframes which psychologists rarely consider, and the field will probably be forced to dig a little deeper into history in light of these findings.

Globalisation and its discontents

Henrich’s theorising has clear implications for organisations whose ambitions span continents, including the inherent challenges of managing cultural differences. However, Henrich’s historical insights seem most relevant to aiding international development and efforts to curb corruption.

Henrich’s cultural-evolutionary perspective on modern history helps us understand how countries like Japan and China have managed to adapt rather quickly to a globalised world, whilst others including Iran and Iraq have struggled greatly (as large parts of the Islamic world still have intensive forms of kinship).

Evolutionary psychologists are fond of describing modern ailments as evolutionary mismatches (that is, heritable traits that were selected for in our ancestral past, which are now misaligned with the demands of the modern world). However, Henrich has identified a new strain of evolutionary mismatches: mismatched in our cultural-evolutionary psychology. In other words, a mismatch between societies’ culturally acquired customs and know-how, and the here-and-now.

What does this mean? To be frank, we can’t assume institutions that work in the Western world can just be lifted and dropped elsewhere— especially in regions where kinship ties remain strong. As stated by Henrich; “Modern formal institutions are now to a degree available “off the shelf”, though their performance depends on the cultural psychology of the populace.”

The following passage hammers the point home:

Many policy analysts can’t recognise these misfits because they implicitly assume psychological unity, or they figure that people’s psychology will shift to accommodate the new formal institutions. But, unless people’s kin-based institutions and religions are rewired from the grassroots, populations get stuck between “lower level” institutions like clans or segmentary lineages, pushing them in one set of psychological directions, and “higher level” institutions like democratic governments or impersonal organizations, pulling them in others: Am I loyal to my kinfolk over everything, or do I follow impersonal rules about impartial justice? Do I hire my brother-in-law or the best person for the job?

Henrich continues:

This approach helps us understand why ‘development’ (i.e. the adoption of WEIRD institutions) has been slower and more agonising in some parts of the world than in others… Rising participation in these impersonal institutions often means that the webs of social relationships, which had once ensconced, bound, and protected people, gradually dissolve under the acid of urbanisation, global markets, secular safety nets, and individualistic notions of success and security. Besides economic dislocation, people face the loss of meaning they derive from being a nexus in a broad network of relational connections that stretch back in time to their ancestors and ahead to their descendants.

Instead of pretending these cultural differences don’t exist, Henrich implores policy wonks to cater their strategies depending on community’s norms and practices. If social engineers are serious about improving the human condition, they must work with, or work around, such cultural-evolutionary mismatches. Just as importantly, Henrich invites social planners to consider how their interventions might alter people’s psychology centuries down the road.

The fathers who banned cousin marriage could not have fathomed the reverberations their actions would have across space and time. With a dizzying array of social changes, technological breakthroughs and environmental problems engulfing humanity in the 21^st century, there will inevitably be profound and enduring changes seared into our collective psyches over the coming decades and centuries.

On the one hand, trying to predict the psychological impacts of these awesome forces would be wise, however fallible our forecasting is. On the other hand, Henrich illustrates the inherently unpredictable nature of cultural evolution– and the weird places it can take us to.

Written by Max Beilby for Darwinian Business.

The Weirdest People in the World: How the West Became Psychologically Peculiar and Particularly Prosperous is published by Allen Lane (£30). Click here to buy a copy.