The Medieval Sources of the West's Peculiar Psychology and Particular Prosperity

Thomas Aquinas lives in the popular and scholarly imagination alike as the paradigmatic medieval man, awaiting the birth of modernity amid the ruins of classical antiquity. But Aquinas in fact described himself as “modern,” at least in comparison with Dionysius the Areopagite, whose reliance on Plato he regarded as passé: “The blessed Dionysius uses an obscure style in all his books. . . because he generally uses the Platonists’ style and manner of speaking, which is not customary with moderns (qui apud modernos est inconsuetus).”[1] Harvard anthropologist Joseph Henrich would agree: in his recent The WEIRDest People in the World (Farrar, Strauss, & Giroux, 2020),[2] he argues that many of the traits and habits of mind that are most distinctive of the modern world were already well-developed in high-medieval Europeans such as Aquinas.

WEIRD People

The WEIRDest People in the World chronicles the origins of societies which are “Western, Educated, Industrialized, Rich, and Democratic” (WEIRD), at least by comparison with other populations around the globe. As Henrich and his co-authors showed in an influential 2010 paper, however, “WEIRD” people are psychological as well as economic or political outliers: we are individualists rather than collectivists; we are unusually prone to analytic rather than holistic thinking, and to fixating on universal principles rather than particular relations; and we have a distinct bias toward feelings of guilt rather than shame.

Whence the WEIRDos? Humanists are apt to respond to this question with some kind of intellectual genealogy, arguing that it was Scotus (or Ockham, Luther, Descartes, Spinoza, or Kant, to sample just some of the most popular choices) whose innovations set the West on the path to modernity. (Not coincidentally, the academic telling this story can periodically be seen casting admiring glances in the mirror, marveling at the vast influence his discipline exercises over the lives of bankers and plumbers alike.) Henrich, by contrast, tells a deeper and more compelling story than mere intellectual history can offer, showing that each of the figures named above was almost certainly already WEIRD in important ways, and for reasons that at least originally had little to do with the univocity of being or metaphysical voluntarism.  

The protagonist in Henrich’s whodunnit is not an intellectual at all, but rather a loose set of novel policies regarding marriage implemented with increasing rigor by the medieval Western church, in a process that was well underway by Pope Gregory the Great (d. 604), and largely complete by the time of Pope Gregory VII (d. 1080). This “Marriage and Family Plan” (MFP) eventually destroyed the tribal societies that formerly dominated Western Europe, and—as we will see below—set the continent on its distinctive path toward WEIRDness.

Our Extended Brains

The MFP actually comes near the end of Henrich’s story, however, which begins in his earlier book, The Secret of Our Success (2015). This book seeks to explain what sets our species apart from other primates, which he specifies as our capacity for cumulative (inter-generational) cultural learning—in effect, our capacity for tradition. Human children, as he documents, do not actually out-perform chimpanzees on most measures of intelligence; we are true outliers only in our capacity for social learning. This ability is super-charged by language, which allows us to store a vast quantity of information in a “collective brain” extended not only in space but—still more importantly—in time.

Henrich exploits a grim set of natural experiments to demonstrate how little individual human intelligence counts for in the Darwinian struggle for survival: groups of European explorers who became stranded in unfamiliar environments—the Arctic, the Australian Outback, even the coast of Florida—consistently and catastrophically failed to adapt to them, despite the fact that humans have lived in all of these places for millennia. After the Burke and Willis expedition became lost in Australia’s interior in 1860, the local Yandruwandrha tribe showed them how to identify the nardoo plant whose seeds formed the staple of their diet. Unfortunately, since the explorers did not understand the complex processes by which the Yandruwandrha detoxified the plant, they still slowly poisoned themselves to death by eating it.

Still more interesting is the fact that the Aborigines themselves almost certainly did not understand why the culturally inherited practices they employed were effective at detoxifying nardoo. Unprocessed nardoo, Henrich observes, contains high levels of the enzyme thiaminase, which if consumed “depletes the body’s store of thiamine,” which in turn “causes the disease beriberi,” which killed Burke and Willis. The Yandruwandrha avoided beriberi by exposing their nardoo flour to ash while heating it, “which lowers the pH and may break down the thiaminase,” and by eating it “using only mussel shells, which may restrict the thiaminase’s access to an organic substrate that is needed to fully initiate the B1-destroying reaction.”[3]

The rich and vital knowledge carried in Yandruwandrha traditions about food preparation seems to be largely tacit, embedded in the practices themselves, and enacted unawares by the practitioners, who participate in an intergenerational process of refining them through tinkering and trial-and-error. “There’s no evidence,” Henrich writes in The WEIRDest People in the World, “that people designed these institutions, or even understand what they do” (78). As he emphasizes, this is no outlier, but the rule in human societies—most of the knowledge we need to survive, much less thrive, is culturally inherited and socially distributed, and this proportion only increases as a society becomes more complex. (Could you build your own refrigerator?)

Of Polygamy and Polytheism

The most deeply rooted cultural norms in any society concern marriage and family, for the simple reason that, as Robert Jenson observed, any society which takes no thought for its survival into the next generation need not bother taking thought for anything else.[4] Outside the modern West (including in the tribes—i.e., the Goths, the Franks, the Quadi, the Marcomanni—who dominated Europe prior to the MFP), these norms have typically focused on cementing and extending relations of kinship: “People lived enmeshed in kin-based organizations within tribal groups or networks,” Henrich writes, which were bolstered by practices such as corporate ownership of land, cousin-marriage, polygyny (one, typically elite, husband with several wives), easy divorce-and-remarriage (162-63). These practices reinforce kin networks and increase the odds that the leading figures in a particular lineage will produce an heir. (For the problems that ensue when the heir is not forthcoming, please consult any biography of Henry VIII.)

As societies scaled up in size, particularly with the advent of agriculture, they overlaid kinship with other forms of imagined community, notably religion. Harvard anthropologist that he is, Henrich is no great personal friend of organized religion: “Dualistic conceptions like souls or ghosts should make about as much sense to us as a person who only exists on Tuesdays and Thursdays,” he writes, later adding, “evolving gods have justified war, blessed genocide, and empowered tyrants (see the Bible)” (130, 149).

Nonetheless, he recognizes that, far from being Marx’s opiates for the masses or Freud’s collective neuroses, religions play a crucial role in human societies, both in forging a collective identity among unrelated individuals and in promoting pro-social behaviors within groups. Moreover, these effects become stronger as the gods at the center of religious life become more powerful and more universal in their moral demands, evolving from the ancestors or nature-spirits of many hunter-gatherer societies to, e.g., the omnipotent and omniscient God of the biblical religions.

Henrich notes that “God-primes”—such as being shown the sentence, “the dessert was divine” in an experimental setting, or hearing the Muslim call to prayer in a Moroccan marketplace—have been shown to increase honesty and even generosity—but only among religious believers (120-26). Belief in a “contingent afterlife” (i.e., a final judgment by God, or reincarnation based on one’s karma) is particularly potent, being associated globally “with greater economic productivity and less crime” (156). Belief only in heaven and not hell, by contrast, “is associated with more murder”! (157, his emphasis)

The Psychology of Extended Kinship

By the early centuries AD, then, Eurasia bristled with densely-settled agricultural societies, honed by cumulative cultural evolution and knit together by extended kinship and by religious commitment. This social structure, Henrich emphasizes, in turn fostered a particular psychology, one which favors “conformity to peers, deference to traditional authorities, sensitivity to shame, and an orientation toward the collective (e.g., the clan) over oneself” (204). If you principally live and work with relatively close relatives, on whose goodwill and good-fortune your own prosperity depends, you will likely be more disposed to social conformity and more sensitive to its violations than someone who lives among and works with un-related acquaintances.

Polygyny also has fateful consequences for the psychology of men in particular. This family structure encourages elite men to take multiple wives, which creates a surplus of low-status men who can’t marry, and so are often left frustrated and adrift. With little to lose, such men are far more likely, as Henrich documents, to commit crimes or take wild risks than are married men, whose social ties and (prospects for) children give them a stake in the future (285-86).

China’s recent “one-child” policy offers Henrich another grim natural experiment to test this theory. The one-child policy produced a surplus of 30 million boys relative to girls across China by 2009, largely via the widespread use of sex-selective abortion. “In each province, about 18 years after the one-child policy was implemented,” Henrich writes, “the pool of excess males reached maturity and crime rates started going up…rising nationally at 13.6 percent per year” (286).

The Marriage-and-Family Plan

In late-ancient Eurasia, virtually everyone lived in extended kindreds buttressed by moralizing religions—until they suddenly did not. “Between about 400 and 1200 CE,” Henrich writes, “the intensive kin-based institutions of many European tribal populations were slowly degraded, dismantled, and eventually demolished by the branch of Christianity that evolved into the Roman Catholic Church…Then, from the ruins of their traditional social structures, people began to form new voluntary associations based on shared interests or beliefs rather than on kinship” (167-68).

As Henrich shows, the late-ancient Western Church began to enforce a package of social policies for its members which, e.g., insisted on lifelong monogamy with little scope for remarriage after divorce; banned marriages between even distant relatives, including in-laws and god-siblings; and eroded customary inheritance laws. Taken together, the MFP profoundly undermined Europe’s tribes “by (1) establishing a pan-tribal social identity (Christian), (2) compelling individuals to look far and wide to find unrelated Christian spouses, and (3) providing a new set of norms about marriage, inheritance, and residence that would have set a foundation on which diverse tribal communities could begin to interact, marry, and coordinate” (193).

The diffusion of the MFP had long-lasting effects on the economic and political organization of European societies as well. “Unshackled from corporate landholdings and ancestral rites, people began to voluntarily join a variety of associations,” Henrich writes. Europeans “began trickling into newly forming towns and cities,” and began enthusiastically forming voluntary associations, such as “guilds, monasteries, confraternities, neighborhood clubs, universities, and other organizations” (311-12). In short, the MFP made it impossible to sustain tight-knit communities based on extended kinship, and so gradually transformed the West into a society of nuclear families cooperating via impersonal markets and voluntary societies.

Henrich acknowledges his uncertainty about what motivated the Western Church to adopt the MFP, but he clearly favors the view that the Church simply stumbled sideways (in good Darwinian fashion) into a winning combination of marriage regulations. Nonetheless, this impulse perhaps causes him to understate the extent to which the MFP was a deliberate policy,[5] and even a natural culmination of the Church’s ambition to overthrow and overshadow the pagan social order it met in its mission fields.

This evangelizing mission was never simply “religious” as opposed to political, social, or economic. As David Bentley Hart observes, the Church always understood the first Commandment (“Thou shalt have no other gods before me”) as “a call to arms, an assault upon the antique order of the heavens—a declaration of war upon the gods. All the world was to be evangelized and baptized, all idols torn down, all worship given over to the one God who, in these latter days, had sent His Son into the world for our salvation.” In time, the Church won this “long and terrible conflict” with pagan antiquity: “the temples of Zeus and Isis alike were finally deserted, both the paean and the dithyramb ceased to be sung, altars were bereft of their sacrifices, the sibyls fell silent, and ultimately all the glory, nobility, and cruelty of the ancient world lay supine at the feet of Christ the conqueror.”[6]

The MFP might be understood as a dimension of this war upon the gods: it rent the seamless and sacralized fabric of family, politics, and religion, and embedded converts in a new social world shaped pervasively by the Church. As Henrich himself notes, “With the weakening of kinship and dissolution of tribes, Christians seeking security could more fully dedicate themselves to the Church and other voluntary associations” (193). In the process, the Church acquired not only ex-pagans’ allegiances, but increasingly also their property—by 1200, as Henrich notes, the Church owned approximately one-third of the land in Europe (193).

Making Europe WEIRD

Whatever the precise motivations for the MFP, Henrich makes a strong case that it had profound effects on both the social organization and the psychology of those subject to it. In contrast with the aggressive, womanizing men fostered by polygynous societies, monogamy presses men to focus their time and energy on supporting one woman and their few children. Monogamy also “shifts men’s psychology,” and even their physiology (e.g., reducing their testosterone levels), Henrich notes, “in ways that tend to reduce crime, violence, and zero-sum thinking while promoting broader trust, long-term investments, and steady economic accumulation” (287). In effect, monogamy domesticates men, restraining their propensities for promiscuity and aggression, a fact which perhaps explains why it has emerged from its historically marginal status to overrun the globe in recent centuries.

Likewise, where extended kindreds foster deference to tradition and attunement to honor and shame, “success in individual-centered worlds favors” the cultivation of WEIRD traits, such as “greater independence, less deference to authority, more guilt, and more concern with personal achievement” (204). And instead of the “inter-personal prosociality” of extended kindreds (as in the Arab proverb, “My brother and I against my cousin; my brother, my cousin, and I against the world”), medieval Europe’s trade-centered cities encouraged “impersonal prosociality,” with one moral code to govern every interaction, from family to strangers, since success in the marketplace requires a reputation for fairness and honesty. And a norm of impersonal pro-sociality in turn encourages, not other-directed shame, but instead a heightened sense of guilt over transgressions (304).

A society of nuclear families relating via impersonal legal and economic institutions naturally privileges “impersonal” or “analytical” modes of thought over organic and holistic ones.[7] Henrich follows the historian Brian Tierney in locating the growth of interest in “natural rights” to the disciplines of high-medieval civil and canon law. He suggests that the same universalizing, analytical impulse that produced “rights-talk” was also a major driver in the bid to model the universe in terms of uniform, mathematical laws (407). The rule of law, subjective rights, and mathematical and experimental science are all distinctly “WEIRD,” Henrich emphasizes, emerging from a socio-cultural setting which was particularly attuned to them, even as they migrate to other settings, in the process partially remaking those host cultures in their own image.

The gradual diffusion of the Western Church offers a natural experiment which Henrich brilliantly exploits for testing the hypothesis that the MFP caused WEIRD psychology, rather than merely preceding it. The spread of bishoprics in communion with the Pope acted “as a time-release dosage of the MFP, measured in centuries of exposure to the Church. . . The stronger the MFP dosage ingested by a population,” Henrich shows, “the weaker their kin-based institutions,” and the WEIRDer their psychology today (200).

“A millennium of MFP exposure,” Henrich notes, “is associated with nearly a 20-percentile-point drop in people’s willingness to go along with the group to give the same wrong answer in the Asch Conformity Task.” It also “increases voluntary blood donations fivefold, cuts people’s willingness to exaggerate their die rolls [in an experiment testing honesty] by half, and reduces the number of unpaid parking tickets from nearly seven per member in a diplomatic delegation to only one ticket for every 10 members” (234). Henrich shows, moreover, that the MFP had profound effects on the political structure of the societies which adopted it: “After the Church arrives, the chances that a city adopts some form of representative government jumps [from 0] to 15 percent and then increases continuously for the next six centuries, topping out at over 90%” (319).

The MFP can even explain fine-grained differences within individual European countries, as in the notorious divide between prosperous northern Italy and its Mafia-ridden South. As Henrich notes, “Southern Italy. . . wasn’t fully incorporated under the papal hierarchy until after the Norman conquests of the 11th and 12th centuries. Prior to this, Sicily had been under Muslim rule for roughly two and a half centuries.” Rates of cousin marriage are consequently 10x higher in southern Italy than in the north, and the result is a much higher level of social trust and impersonal pro-sociality in the North than in the South. “In southern Italy,” Henrich points out, “including almost all of Sicily, the rates of blood donations are near zero,” while “in some northern provinces, they reach 105 donations…per 1000 people per year” (245-46).

WEIRD Backsliding

So far, our journey with Henrich has been largely descriptive, following his argument that the medieval MFP is in fact largely responsible for the rise of WEIRD societies. But now, we need to ask some normative questions about where we find ourselves today. The five years since the Brexit vote and the election of Donald Trump have seen a sharp rise in concerns about the decline of liberal norms and institutions across the West, in favor of various forms of identity politics, rooted in nationalism and nativism on the Right, and in various victimized classes (defined by race, sexual orientation, gender, etc.) on the Left. Have we—a representative liberal,[8] say Mark Lilla or Francis Fukuyama might worry—somehow gone off our WEIRD meds, and so slipped back into the pre-modern pathologies they held at bay?[9]

Liberal polities promise a rationalized world, embodied in the thought experiment of the social contract, a pre-political moment in which reasonable individuals agree together on a political future which will maximize their liberty, their wealth, or their equality. The rule of law and the imperatives of the market are meant to ensure that each person can stand before every other as, first and foremost, an independent citizen rather than a bearer of narrower identities and allegiances. That so many across the West today are relying in greater and greater measure on more elemental forms of identity, such as loyalty to tribe or creed, is a symptom of widespread disillusionment with the liberal settlement. 

Cumulative Cultural Evolution as Burkean Tradition

But at this point a conservative will be apt to observe, with more than a touch of Schadenfreude, that this unraveling was inevitable, because liberalism destroys the social and moral capital needed to sustain it. In Henrich’s terms, the conversative worries that WEIRDness necessarily undermines the basic processes of cumulative cultural evolution on which all human societies depend.

Indeed, Henrich’s theory of cultural evolution was nicely summarized avant la lettre by the conservative philosopher and statesman, Edmund Burke: “We are afraid to put men to live and trade each on his own private stock of reason, because we suspect that this stock in each man is small, and that the individuals would do better to avail themselves of the general bank and capital of nations and of ages.”[10] The individual’s “private stock of reason,” is not only paltry compared to “the general bank and capital of nations and of ages,” but is overwhelmingly built up only by successive drafts on that accumulated capital. The rational and autonomous individual is at least in part a social artifact, because the possible forms of a flourishing human life can only be discovered through cooperative processes which extend in time as well as space.

Thomas Aquinas puts this point with particular clarity:[11]

So, it is natural to man that he should live in a society of many. More fully: in other animals, there is imprinted a natural inclination toward all the things which are useful or harmful to them, as the sheep naturally esteems the wolf to be its enemy. . . But man has a natural knowledge of those things which are necessary for his life only in common, as he, so to speak, strives through reason to move from universal principles to those things which are necessary for human life. But it is not possible for one man to attain, through his own reason, to everything of this sort. And so it is necessary to man that he live in a multitude, that one might be helped by another.[12]

Where snakes are born ready to hunt, and horses born (almost) ready to run, human beings are born with the potential to become the language-using, tool-making, culture-forming apex predators that other animals learn to fear—but only with the potential. Our children are effectively helpless for a period which in other species would be a life-span. Even in maturity, and particularly in urban, technological societies, their acquired knowledge is but a drop in the bucket of the pooled wisdom on which they will daily, mostly unthinkingly, depend in the course of their lives.

Indeed, something like Aquinas’s thought seems implicit in Burke’s revision of social contract theory: though “society is indeed a contract,” he proposes, it is one whose “ends. . . cannot be realized in many generations,” and so “becomes a partnership not only between those who are living, but between those who are living, those who are dead, and those who are to be born.”[13] The newly-born inherit land and capital, yes, but above all culture, that indispensable store of speculative, technical, and social knowledge which fits them with proven solutions to perennial problems, and good starting points in the hunt for solutions to new ones. 

A WEIRD Revolution Gone Awry

Burke wrote his Reflections on the Revolution in criticism of revolutionary France, which represented a kind hypertrophy of WEIRD skepticism, individualism, and universalism. During the Revolution, the inherited and organic fabric of France’s “throne-and-altar” society was deliberately rent asunder, and rationally-planned alternatives were substituted in their place: the messy provincial map was wiped clean and replaced with a grid; ancient systems for measuring time, volume, and distance were thrown out and replaced with decimal systems; and France was outfitted, virtually overnight, with social mores and political and religious institutions which were planned on an ostensibly rational basis (“the Rights of Man” and the Cult of Reason).

I do not mean to say that the French Revolution was all bad, nor the ancien régime worth our tears today. Burke himself would have been glad to see France abandon its royal absolutism for a constitutional monarchy on the model of Britain’s.[14] But Burke was strikingly prescient in foreseeing that the Revolution’s indifference to time-tested institutions and to the proclivities of human nature had set it on a path to chaos, which would end—as he predicted in 1790—with the rise of “some popular general. . . who possesses the true spirit of command,” to become “the master of your Assembly, the master of your whole republic” (q.v. Napoleon’s coup on the 18th of Brumaire, 1798).[15]

“In old establishments,” Burke observes, “various correctives have been found for their aberrations from theory. Indeed, they are the results of various necessities and expediencies. They are not constructed after any theory; theories are rather drawn from them,”[16] as principles of the common law are deduced from the mass of individual cases which form its basis. Old establishments—the British Constitution is Burke’s paradigm—are the products of cumulative cultural evolution’s slow and uneven sifting of norms and institutions over time.

However, it’s essential to note that Britain’s parliamentary monarchy is itself a WEIRD institution, embodying commitments to the rule of law and individual liberty that are distinctive products of the MFP. So long as the fundamentally conservative deference to the tacit wisdom of cumulative cultural evolution constrains WEIRD reformism, the two can profitably be fused, as in Burke’s defense of American independence or his leadership in the impeachment of Warren Hastings for his abusive misrule of India during his tenure as Governor-General.

The problem, however, is that analytical, individualist, universalizing WEIRDos are generally impatient both with slow improvements to good-enough institutions and with our enduring entanglement with unchosen ties. They are particularly uncomfortable with the mediating institutions—the family, the church, the tribe—which hem in individuals and limit the reach of universal norms and institutions. This impatience is often understandable and indeed commendable: women and black Americans, to take the two most obvious instances, waited far too long to be admitted to equal standing under the law with white men, and their enjoyment of that equality still remains lamentably uncertain in many cases.

Are We Too WEIRD?

Nonetheless, the WEIRD ambition to remake the world as a mere assemblage of individuals united by ever-more-universal norms and institutions has arguably become self-consuming. Economic globalization is a profoundly WEIRD undertaking, aimed at joining the whole world in an impersonal market in goods and services. It has produced enormous wealth, particularly for white-collar workers in the West and low-skilled laborers in the developing world, but at the cost of destroying the livelihoods, and ultimately the communities, of formerly prosperous blue-collar workers across the West. Neo-liberal economists promised “creative destruction”: destruction has arrived in spades, but the new industries have so far failed to materialize, for sound empirical reasons which liberalizers from David Ricardo on have ignored.[17] Instead of a new economy, the Rustbelt and other depressed regions have developed a raging epidemic of “deaths of despair” (from drug overdose, alcoholism, and suicide).

National or regional markets pose obstacles to a fully WEIRD world of individuals united only by universal norms, but even they are only minor irritants compared with the human body itself, a bearer of millions of years of biological baggage, and stubbornly stamping every cell of our bodies as male or female. Perhaps unsurprisingly, the latest enemy of modern individualism and universalism is now the sexed body itself, a fact evident in the last decade’s explosive increase (4415% in the UK) in diagnoses of “rapid-onset gender dysphoria” in adolescent girls in particular. Many of these teens have been hurried into puberty-blocking hormones, testosterone (or estrogen, as the case may be), and even double mastectomies by psychologists and physicians who apparently agree that the highest human good is the flesh’s total docility to the untrammeled will—a WEIRD development, if ever there was one.

In The Communist Manifesto, Karl Marx observed that, under capitalism, “All that is solid melts into air, all that is sacred is profaned.” In its first inception, WEIRDness proved a powerful solvent of the ancient world’s rigid social hierarchies, creating a dynamic and wealthy world of nuclear families, voluntary societies, and government by an increasingly broad franchise. Henrich does a masterful job of showing the important role the Church played in bringing to birth so many modern institutions and norms for which we are right to be grateful, including “WEIRD monogamy,” representative government, and the Scientific and Industrial Revolutions.

But we all know that dosage matters. “Too much and too little wine,” as Pascal put it in the Pensées: “Give him none, he cannot find truth; give him too much, the same.” The evidence seems to be mounting that we have long passed the golden mean of WEIRDness. Our collective biases toward individualism and universalism seem to be blinding us to the important goods offered by our unchosen attachments to place, to family, and even to our aging, awkward, and sexed bodies. And through a kind of collective return of the repressed, many of those left alone and adrift by this dissolution are seeking security in the most enduring and atavistic forms of identity. To consolidate and build on the real achievements of WEIRDness, perhaps we need to prune it back, to relearn the limits placed by biology and history on our self-fashioning.