CHAPTER 2
Family
The family … must be regarded as the natural, primary cell of human society.
Our closest living relatives today, chimpanzees and bonobos, go about their lives in a manner that is probably very similar to our common ancestor. Living in a forest environment, they spend their time swinging from branches and moving across the ground largely on all fours. As our human lineage diverged, we became increasingly adept at walking upright on our legs – we developed bipedalism. As the forested biomes in our evolutionary cradle of East Africa dried out and were replaced by grasslands, this allowed our ancestors to successfully inhabit the savannah and ultimately disperse around the world.
Alongside the development of bipedalism, a second major change was playing out: our ancestors were getting smarter. Over time, hominin species developed larger and larger brains – as can be seen from the increasing volume of the cranial cavity in fossilised skulls – and therefore were capable of progressively greater levels of intelligence, leading up to the exquisite aptitude that our modern species, Homo sapiens, has for language, cooperation, problem-solving and tool-use.
There’s a problem, though. The two developments of becoming bipedal and brainy aren’t readily compatible with each other. Mammals give birth by pushing the foetus out of the womb through a hole in the middle of the pelvis. Yet the adaptations to our skeletons and pelvis that enabled us to walk upright are in conflict with the need for a wider birth canal to accommodate the passage of bigger skulls. The human species today effectively sits right on the cusp of these two mutually exclusive design principles.1
The mechanics of birth, therefore, threatened to limit how brainy our ancestors could become. The solution hit upon by natural selection was to extend our developmental process long after we emerged from the womb. Compared to other mammals, including the other great apes, human babies are born in a remarkably undeveloped and vulnerable state. While a zebra can effectively get up and walk alongside its mother mere minutes after birth, humans take many years to be able to walk, feed and fend for themselves. All newborn mammals are fed milk by their mothers – indeed, the name for this group of animals comes from the Latin word mamma, meaning ‘breast’ – but the dependence of human babies goes much further than this. It is only after we pass through the hoop of birth that our brains are free to grow, and it is during these tender, formative first years that we learn how to coordinate ourselves and walk, talk and use the intricacies of social interactions.
During this whole, protracted period of development, we are entirely reliant on being carried around, fed, kept warm and protected. This places an enormous burden on the mother’s time – her ability to gather food and care for the infant, all the while protecting herself and her other offspring – so much so that for our ancestors, raising a baby became hugely challenging for a mother on her own. Thus, as we evolved to be more intelligent, and so increasingly dependent as babies, there was a strong selection pressure for both parents to take an active role in child-rearing.fn1
PAIR-BONDING
If both parents cooperate and raise their baby together, it has the best possible chance of surviving the vulnerable early years. But each parent needs reassurance that the other is committed to the arrangement. The woman needs to be certain that, in a sexual relationship, the man is likely to stick around through the pregnancy and first years of the baby’s life, when she and the child are in most acute need of assistance. In turn, the man has to be confident that he’s not being cuckolded – the identity of a child’s mother is always clear, but paternity can be much less certain. How can both parties know that their partner is committed to the relationship and any children that may result from it?
The solution that evolution found to this quandary is pair-bonding. If each partner experiences an intense attachment to the other, they will be compelled to cooperate in child-rearing. This human pair-bond is regulated by a hormone called oxytocin.
Oxytocin serves many functions in mammalian reproduction. It stimulates the muscular contractions of the uterus during childbirth and the secretion of milk during lactation but also, crucially, the emotional attachment between a mother and her newborn. All mammalian mothers nurture their young: they suckle them, protect them from predators and teach them vital life skills. Yet experiments have shown that rats that have had the oxytocin messaging blocked after giving birth don’t provide any normal care or attention to their pups.2 On the other hand, virgin female sheep injected with oxytocin will start exhibiting maternal behaviour to a lamb that is not their own.3
While this mechanism of mother-offspring bonding is shared by all mammalian species, it has been modified and extended in humans to create a deep attachment between partners as well. Today, we experience this in the emotion of romantic love. Oxytocin is released in both men and women during sexual intercourse, and especially during orgasm, so that sex helps first to establish and then maintain the pair-bond.4 The different stages of romantic love – from attraction to attachment – involve the release of another key signalling molecule, called dopamine, in the brain’s reward pathway. As we’ll explore in Chapter 6, drugs such as caffeine, nicotine and heroin trigger the same pleasure centre in the brain. The neurochemistry of love is very similar to that of addiction – or you could say, love is a drug.5 Thus evolution has ensured that partners likely to have a baby together are also bound to each other by a mutual hormonal tie.fn2
If a man sees that the woman loves him, he can be confident that she’s not sleeping with anyone else and the children will be his. And in return, if the woman sees that the man loves her, she has a reliable assurance that he will stick around to help raise the baby.7 In crude evolutionary terms, within a pair-bond, partners are exchanging certainty of paternity for a guarantee of resources.
While long-term pair-bonding is an integral part of human reproduction, this does not mean that faithfulness is always absolute nor that such relationships endure indefinitely. In many pairings, the initial, intense, passionate bond of romantic love mellows before long into a calmer attachment, or eventually falters altogether. The period over which the strength of the attachment begins to fade, until the pair-bond effectively dissolves (at least for one of the two partners), has been found to be around four years. Interestingly, this is roughly the time it takes for a child to develop enough that it is no longer critically dependent on the support of both parents.8 Statistical studies show a peak in the divorce rate between the fourth and sixth year of marriage across many different societies9 – evidence for the popular conception of the seven-year itch. It seems evolution invented romantic love to ensure the commitment of biparental child-rearing, but only for as long as it’s needed for reproductive success.
The emergence of this oxytocin-driven web of ties binding both parents and their offspring together created something very special in our history: the family. Many primate species live in social groups, but we humans are unique among the great apes in sticking together in stable family structures.10 What’s more, as we saw in the previous chapter, humans form strong attachments not only to offspring and sexual partners, but also to wider kin, as well as others to whom we are not related – close friends and the social network. Over our evolutionary history, the range of other individuals humans feel a deep connection to has broadened further and further. And this oxytocin system has even been extended to include other animals, as we domesticated wild wolves and cats to become our pets. We are a species of bonders.
The formation of a pair-bond between sexual partners is essentially a mutual exclusivity contract for reproduction, forged biologically by hormones. Thus the institution of marriage is no more than a social practice built on this evolutionary foundation, formalising the bonding already intrinsic to humans. An analysis of 166 societies around the world concluded that romantic love was a universal feature of the human experience. Formal marriage arrangements between a man and a woman also exist in all known cultures, and 90 per cent of people in the world will marry at least once in their lives.11 The cultural norms that have built up around marriage, and are codified in religion or law, specify the expectations associated with the union. These include whether the bride or groom lives with the other’s family, or whether the newlyweds establish a new household together. They set out rules over inheritance and the division of property following separation or the death of one partner. They may also stipulate a transfer of wealth in the form of a dowry or bride price, so that marriage becomes not only a contract between bride and groom, but a transaction between their families.
But in all of the world’s cultures – from the inelaborate betrothal of Hadza hunter-gatherers in north Tanzania to the chant- and ritual-filled Greek Orthodox ceremony to the three-day celebration of a Hindu wedding – at its core, marriage is a public declaration of a couple’s mutually confirmed commitment (or, in the case of a polygamous marriage, commitment between multiple spouses). Wedding customs are culturally specific and have changed over time, but the practice of partners publicly committing to each other in order to regulate reproductive behaviour must be as old as human language, if not older.
Living within family groups, and supporting our close kin, has been a central part of human existence from the beginning of our species. Family has taken a variety of forms, from an extended family of relatives, spanning several generations, living together in the same household, to the nuclear family of a single couple with their children that became common in the post-industrial west (and of which the single-parent family is a variation).12 For much of history, in the absence of state institutions, one’s family was the only resource available to support a person during sickness or old age.
The development of agriculture and the emergence of civilisation introduced another key aspect of family life. When our hunter-gatherer ancestors took to farming and abandoned their mobile lifestyle, the ability to accumulate possessions increased markedly – whether that was pottery, metal tools, a flock of goats or a hoard of precious metal currency. Agriculture also created the concept of land ownership – proprietary rights over a particular tract that is tended and tilled by the same family (or its serfs) to grow crops or pasture livestock.
These possessions could be passed from parents to children, keeping their benefits within the same family (in an extension of the kin selection we discussed in the previous chapter).fn3 We had always inherited physical traits from our parents, but now material wealth could also be transmitted from one generation to the next. And it wasn’t just the assets or land themselves, but also the influence and status that they afforded. For those at the top of society, control over a whole territory and the people and resources within it was also inherited. Steep social hierarchies and levels of inequality developed and perpetuated what would have been unknown to our hunter-gatherer ancestors – rich vs. poor, rulers vs. ruled.
The most prominent position was occupied by the king, the sovereign ruler over an entire state. Those kings able to muster the larger and more formidable armies conquered other chiefdoms which they incorporated into their realm. Over time, patchworks of independent territories fell under the hegemony of a single supreme ruler – a king-of-kings, an emperor.fn4
While children within the elite social strata inherited the wealth and status of their parents, family professions were also passed down within other sectors of society. By being exposed to, and learning, the skills from a young age, sons often stepped into their father’s trade and role within society, inheriting the necessary tools: baker, butcher, miller, mason, sawyer, wright, smith. Indeed, in medieval England, for example, many of these common family trades became adopted as surnames.16
Inheritance customs and laws have varied between societies but are often distinguished between realty (land and buildings) and personalty (such as household goods, personal effects, livestock and cash).17 The central quandary facing any testator was: what’s the best strategy of inheritance to ensure future success? The fairest way for wealth and land to be passed down within a family might be partible inheritance – the sharing of possessions equally among all children, or at least all sons.fn5 But for land inheritance the problem is that with each generation the original tract becomes parcelled down into ever-smaller subdivisions, until eventually each is no longer sufficiently productive. For the aristocracy, this dispersal of territory also represents a disintegration of wealth and influence.
An alternative system is to pass the majority of the family realty to a single heir. Primogeniture – inheritance by the eldest son – began to be adopted in medieval Europe among the feudal nobility (and later among landholding peasants too) and elsewhere around the world. Primogeniture prevents the splitting of estates and the titles and privileges that went with them.
The favouring of the firstborn son with the family’s estate meant that younger sons were forced to seek careers within military service or the Church. Primogeniture is also thought to have been a major factor behind the Viking Age. From the end of the eighth to the mid-eleventh century, fierce sailors erupted out of Denmark, Norway and Sweden and across Northern Europe aboard their longships. After an initial fifty years of smash-and-grab raids on vulnerable coastal monasteries in the British Isles, the Scandinavians increasingly took to settling in the regions they invaded – a shift believed to have been driven by an increase in the number of younger sons in Scandinavia with no chance of obtaining the family’s holdings and so being forced to venture abroad to secure farmland of their own. This expansion eventually produced Viking settlements in England, north Scotland and southern Ireland, as well as in the Baltic, Russia and Normandy (William the Conqueror was himself a descendant of the Viking leader Rollo).20
Many of the conquistadors leading expeditions into Central and South America in the sixteenth century were also younger sons of the nobility who stood to inherit little from their wealthy families.21 Similarly, many of the settlers sailing to North America – and particularly to the plantations of the southern colonies – in the eighteenth century were the younger sons of British gentry, who stood to inherit no land of their own at home but did receive some money to establish themselves elsewhere.
Primogeniture was first rejected in favour of partible inheritance by the New England colonies in the mid-seventeenth century and then abolished by law across the United States shortly after the declaration of independence.22 Within twenty years, the French Revolution had also abolished primogeniture with its sweeping away of the Ancien Régime. Elsewhere, primogeniture declined as societies progressed through the demographic transition (which we’ll discuss in Chapter 5); families began to have fewer children and ownership of land became less central to economic success.23
Today, most nation states are run by representational democratic governments – although with varying degrees of corruption and political repression24 – which accede to power through election. Our leaders are expected to display capability and merit, while nepotism in public life is frowned upon. But this is a relatively recent state of affairs: for millennia, since the earliest emergence of civilisation, absolute rulers have reigned supreme. And while power lay in the hands of a single individual, it was usually inherited within the same family: kingship as intimately tied to kinship.25 The result of this fusion of family lineage and inheritable status is dynasty – an extended family that passes wealth, territory and power from one generation to the next. A dynasty behaves like a superorganism, preoccupied with its own survival and advancement, striving to cling on to and expand its territory, prestige and influence while competing with other families or intermarrying to further their own interests.
Dynasties became such a prevalent feature of human civilisation that their names often serve as a convenient means for delineating historical periods of a particular state, empire or region: we talk about the Tudor age, the Ming dynasty, Tokugawa-period Japan and so on. These names are shorthand and encompass not just the ruling family but the major cultural, socioeconomic, military or technological trends or events dominant at that time.
So although marriage is a universal social construct built upon the human predisposition to form pair-bonds, within dynasties marriage took on a whole new importance. Far more than just the union of two individuals, it represented the tying together of two powerful families; and strategic marriages were meant to cement political alliances. The children born into these marriages intertwined the bloodlines of both dynasties, literally embodying the accord between the two powerful families. The human imperatives of pair-bonding and reproduction became tools of statecraft.
For a royal family, births, deaths and marriages are all political events, and they have profound repercussions for all those living within the kingdom or empire. At the same time, such family dynamics dominate international relations as well. In European history, the kings of one particular dynasty were masters of this grand design.
THE HABSBURGS
Asked to name a great royal family in history, we might think of Charlemagne’s medieval Carolingian dynasty, the House of Bourbon in France or England’s Tudors. But none have had as great an impact across the breadth of Europe, and globally, as the Habsburgs. As the predominant royal family for around half a millennium, they acquired a vast empire across the continent and around the world. The gradual but persistent growth of Habsburg territories happened, on the whole, not through sweeping military conquest but by accumulating crowns in a carefully orchestrated programme of strategic royal marriages.26
Rising from humble origins in Swabia, in today’s northern Switzerland, the Habsburg family’s fortunes experienced a significant boost in the mid-fifteenth century when they were able to manoeuvre themselves into a favourable position within the college of princes who elect the Holy Roman Emperor. The Holy Roman Empire had been founded in 800 when Charlemagne, King of the Franks, was crowned by the Pope as emperor of the Romans, supposedly in continuation of the ancient Roman Empire. From the tenth century it became a largely Germanic empire but included many other kingdoms through Central Europe and down to the Mediterranean and Baltic coastlines.27 Although emperor was formally an elected post, the incumbent was often able to wield sufficient influence to ensure his own son was chosen as successor, in what became a de facto hereditary imperial crown. For three centuries between 1438 and 1740, all the Holy Roman Emperors were Habsburgs,28 and the dynasty was able to merge this conglomerate of Central European kingdoms with its own territories.
The architect of the Habsburg’s phenomenal ascendancy in the fifteenth century was Maximilian I, who actively pursued a policy of dynastic marriages between his family and other prominent royal houses in Europe.29 In 1477, he married the heiress of the Duchy of Burgundy, acquiring not only this territory on the eastern boundary of France, but also the Low Countries (Luxembourg, Belgium and the Netherlands), enabling him to tap the wealth moving through their ports. Maximilian then arranged for his son Philip to marry Juana, the daughter of Isabella of Castile and Ferdinand of Aragon, in 1496. Following the deaths of her elder siblings and nephew, Juana inherited both crowns, and her and Philip’s son, Charles, became the king of a unified Spain.fn6 With this Spanish inheritance the Habsburgs also came into possession of southern Italy, Sardinia and Sicily, as well as settlements along the north African coastline.31 It turned out to be fortuitous timing. Just four years before Philip and Juana’s wedding, Columbus had crossed the Atlantic and discovered the ‘New World’. The Spanish branch of the Habsburg dynasty thus came to rule over a dominion extending far beyond the European peninsula, as conquistadors and colonisers laid claim to vast tracts of territory across the Americas. Then, in 1521, the naval explorer Magellan claimed the Philippine islands for Spain (named after Charles’ son, Philip II).32
Yet Maximilian’s ambitions did not stop there. He arranged for his grandson Charles to marry Isabella of Portugal in 1526. This completed the absorption of the whole Iberian Peninsula into the Habsburg realm, as well as the Portuguese conquests in Brazil, India and the Spice Islands. Maximilian also arranged for his other grandson, Charles’ younger brother Ferdinand, to marry into the Hungarian royalty. When the Hungarian king was killed in battle against the Ottomans in 1526, leaving no heirs of his own, the crowns of Hungary, Bohemia and Croatia also passed into the Habsburg family, delivering the territory that would form the core part of their Central European empire for the next four centuries.33fn7
The Habsburgs had transformed themselves from middle-ranking counts in Swabia to the principal dynasty in Europe. And within just 50 years of prudently plotted marriages, they had acquired over half of the continent;35 what’s more, they had achieved this more or less bloodlessly. As the seventeenth-century saying went: ‘While others wage war, you happy Austria marry!’36 While they had had to defend some of their claims through force of arms (and although Spanish and Portuguese invasions in the New World and South East Asia were brutal), the majority of this astonishing growth in influence had come about through strategic royal unions and the gradual accumulation of crowns and territories through inheritance.37 The Habsburgs were true grandmasters of the game of thrones.fn8
They also benefitted from a good degree of biological luck. In the system of inheritance and succession, royal families that fail to produce any surviving children, or at least any male heirs, risk having their titles and territories claimed by more distant relatives or in-laws. For centuries, the Habsburgs reliably produced male heirs, or at least surviving nephews and male cousins, through whom they could lay a claim to the kingdoms they had married into which had faltered in the male line. By way of this genealogical endurance, by simply out-surviving rival families, the Habsburgs were able to absorb their territories and wealth – we might call it the ‘last man standing’ approach to territorial expansion.39 The historian Martyn Rady calls it ‘the Fortinbras effect’, after the Prince of Norway in Shakespeare’s Hamlet, who arrives at the end of the play to find all his rivals dead and so claims the vacant throne.40
By the mid-sixteenth century, the Habsburgs had manoeuvred themselves to become a dominant power not just within Europe but across the Atlantic and Pacific Oceans – the arms of this single family encircling the world.41 And this vast dominion was all ruled by one man, Charles V, Holy Roman Emperor, the first ruler in history to reign over an empire on which the sun never set. But he knew that he couldn’t pass this all on to either his brother or his son, as neither would quietly concede their claim to the other, and so at the point of its greatest extent, the Habsburg empire was cleaved in two. Maximilian’s grandsons initiated two branches of the Habsburg dynasty: Charles passed the lands of the Spanish Habsburgs (including the Low Countries and the worldwide Spanish possessions) to his son, Philip II; while Charles’ brother Ferdinand I received the ancestral lands in Austria, and his Central European descendants continued as rulers of the Holy Roman Empire.42
At the beginning of the eighteenth century, Habsburg global power suffered a sharp knock with the loss of the Spanish branch, but the Central European dynasty remained a considerable European power, morphing into the Austro-Hungarian Empire in 1867. The family was still an instrumental player in the affairs of the twentieth century when, on 28 June 1914, the heir presumptive, Archduke Franz Ferdinand, was assassinated in Sarejevo. Within little more than a month, the world was being consumed by the most devastating war it had yet seen. Defeat in the First World War delivered the final blow to Habsburg power with the collapse of the Austro-Hungarian Empire and the dynasty losing all its remaining territories. (The family itself still survives: Karl von Habsburg, grandson of the last Austro-Hungarian emperor, Charles I, serves today as an Austrian politician.) But for over four hundred years, this single extended family had been a principal player in European and global affairs.
MONOGAMY VS POLYGAMY
The Habsburg dynasty, and indeed all of Europe and its colonies around the world, lived with a cultural norm of monogamy. But polygamy has been extremely prevalent through world history. An ethnographic survey of 849 human cultures – including both hunter-gatherer groups and agricultural societies – found that 83 per cent of them are polygamous, with virtually all of these containing polygyny rather than polyandry.43 These similar terms can get a little confusing. Polygamy is the general term for having multiple spouses. Polygyny is the form of polygamy where a man has multiple wives, and polyandry is a woman having more than one husband. Polygyny is far more common than polyandry, but while it is permitted in many cultures, it is important to note that even in these societies it is usually only the highest-status men who are able to support multiple wives, and so the majority of men and women in those societies still live in monogamous pairings.44
Polyandry is found in less than 1 per cent of societies in anthropological records.45 While there have been examples of powerful queens taking many husbands – such as Nzinga, a mid-seventeenth-century warrior-queen of Ndongo and Matamba (in today’s Angola)46 – polyandry typically involves brothers marrying the same woman, often in response to environmental circumstances.47 For example, in the Tibetan highlands and foothills of northern India, the harsh landscape makes it difficult to cultivate enough food to support a family, so when a plot of land is partitioned too often between family members it becomes insufficient. With fraternal polyandry, a group of brothers marries the same woman, and they work together to farm their land so it doesn’t become subdivided in each generation among separate families.48 It is therefore a different solution to the same problem that primogeniture addresses. Several men married to one woman also produces slow, sustainable population growth, so polyandry offers a demographic solution to ecological constraints.
Monogamy is believed to have been the predominant condition for our hunter-gatherer ancestors. Today’s Hazda people, living in the savannah woodlands of northern Tanzania, represent a fairly typical example of the hunter-gatherer lifestyle and so offer insights into how humanity probably lived tens of thousands of years ago. The Hazda form small foraging bands of around 30 individuals, who move camp about every two months as they exhaust the available food in one area. These groups are very fluid, with individuals drifting between nearby camps or whole groups splitting or merging. All food brought back is shared among everyone in the camp. With no means of preserving food, the Hazda aren’t able to save reserves for later or build up a surplus; their mobile lifestyle also means they keep few material possessions and carry only what they need to survive. Theirs is a remarkably egalitarian society, without stark resource disparity or significant hierarchy between adults, and with equality between men and women. Monogamy is the social norm among the Hazda, with very few men having two wives at the same time; usually, one of the women becomes unhappy in a polygynous relationship and leaves. As the women are generally able to gather enough food for themselves, or share with everyone else what is brought back to the camp, their self-sufficiency frees them to divorce their husband.49 Anthropologists assume that our hunter-gatherer ancestors would have led similar lives.
As we have seen, with the emergence of agriculture, individuals started to accumulate wealth and status, and highly hierarchical societies developed. Men at the top of the social pyramid were able to support several wives, and polygyny became the widespread norm, rather than the exception.50 The Kaguru, for example, agrarian people that live south-east of the Hazda in today’s Tanzania, practise polygyny.51 Polygyny was also the norm for the ruling elites in Asia and the pre-Columbian Americas.52 Poor men, on the other hand, have been monogamists all round the world.53
While polygyny is obviously advantageous for the reproductive potential of powerful men, wives can also benefit from the arrangement. In an egalitarian society with roughly uniform distribution of resources among individuals, such as a hunter-gatherer community, females benefit most from the undivided attention of one man for co-parenting their investment-intensive offspring, rather than sharing that man with other females. But if there is greater disparity in males in terms of their status, wealth or other ability to provide, it may be in the woman’s interest to have a smaller share of the ample resources of a wealthy, high-status male, rather than be the sole mate of a resource-poor male.54
The anomalous pattern of monogamy in the West today originated in the ancient civilisations of the Mediterranean. In efforts to foster a more egalitarian and democratic society – by offering all male citizens the chance to find a wife – from around 1000 to 600 BC, the Greek city states enacted laws regarding monogamy.55 These cultural norms were later adopted by the Romans and expanded with the introduction of new laws to restrict polygamy and strengthen the institution of monogamous marriage. Between 18 BC and AD 9, for example, Emperor Augustus, concerned with moral decay and political decline, restricted the inheritance unmarried men would be eligible to receive and legally formalised the process of divorce so as to discourage serial monogamy. Furthermore, married men were prohibited from taking concubines – although, they were permitted to have extramarital sex with prostitutes and to exploit slaves, who often bore illegitimate children.56 While polygyny was officially viewed by the ancient Greeks and then Romans as a degenerate custom of uncivilised barbarians and monogamy as the social and legal norm, in reality many men practised a form of de facto sexual polygyny.57
The militaristic expansion of the Roman Empire forced monogamy upon much of Europe, and after the collapse of the Western Roman Empire, the Christian Church continued to promote this cultural norm.58 There is nothing inherently monogamous in the Judaeo-Christian tradition. The patriarchs and kings of the Old Testament had several wives – most notably King Solomon who is said to have had 700 wives and 300 concubines.59 Nor did the rich and powerful men of Christian Europe remain strictly monogamous; they often had one wife, who bore them legitimate heirs, but also a number of mistresses or concubines. With the colonial expansion of Christian European states from the early sixteenth century, their cultural norms and legal systems around monogamy were exported around the world and imposed upon indigenous societies. Today, monogamous marriage prevails around the world – but polygamy is legal in 28 per cent of sovereign states, mostly Muslim-majority countries across North Africa, the Arabian Peninsula and Southern Asia.60
It is clear, therefore, that humanity has a predilection for polygamy but in our ancestral condition, this was kept in check by the resources available in a hunter-gatherer community, and monogamy prevailed. The social inequality brought about by agriculture, however, allowed polygynous impulses to be manifested by powerful men. In Europe, legal systems developed to reinstate monogamy as the cultural norm, which was then also enforced across the world by colonialism. Indeed, if people didn’t already have a proclivity towards entering into polygamous marriages, there would have been no necessity to outlaw it. Kings and emperors through history permitted themselves to support many wives or maintain large harems – as we have seen, polygamy is a consequence of social hierarchy. Wealth disparity is as large today as it has ever been, with a vast gulf between the ultra-rich industrialists and internet entrepreneurs and those living in destitution. Were it not for the prevailing cultural norms, reinforced by top-down laws, and the US had followed the pattern seen in many polygynous societies, it could be the most extreme polygynous state in history. At the time of writing, Elon Musk has a personal net worth of nearly a quarter of a trillion dollars. With this fortune he could materially support hundreds of thousands of wives, utterly overshadowing the harems of the greatest despots of history.
DYNASTIC REPRODUCTION
Human reproductive behaviour is a rich, mixed repertoire, and in our history, we have combined the promiscuity of chimpanzees, the monogamy of gibbons and the polygyny of gorillas. We undeniably display a predilection for polygamy, but monogamy became our predominant ancestral condition – and has been culturally and legally enforced in Europe for centuries – even if wealthy, high-status individuals in many societies and civilisations have practised polygyny. The consequences of these two reproductive systems have had a profound influence on world history, particularly when it comes to how political power was passed on from one generation to the next.
In late-medieval Europe, most royal families (as well as those of the aristocracy) adopted primogeniture – sole inheritance of the kingdom by the eldest son. The successor states of the Carolingian Empire, which extended across France, the Low Countries, northern Italy, Austria and Germany, went one step further and expressly forbade not only a woman to ascend to the throne but even inheritance to be transferred through the female line of descent – known as the Salic law.61 What’s more, European monarchies often excluded illegitimate sons from the succession – those fathered by the king but not born of his queen. In this way, the right to rule was defined not by the royal bloodline transferred from the king, but by the marital status of the king and mother of the child.62
The advantage of such clearly established rules of succession was that they minimised uncertainty over the rightful heir and the number of rival claimants to the throne on the king’s death, and so offered a dynasty a smooth transfer of power and a stable state.63 As the French political philosopher Montesquieu wrote in ‘The Spirit of the Laws’ in 1748, ‘The order of succession is not fixed for the sake of the reigning family; but because it is the interest of the state that it should have a reigning family.’64 The heir apparent could also be prepared for his future role as absolute ruler. But while a strict order of succession offers clarity, a system of pedigree over merit risks producing weak or incompetent kings: the person most suitable for leadership is unlikely to just happen to be the eldest son of the previous ruler (especially if the heir apparent is still a young child, or infirm).65
Another problem of primogeniture within the monogamous tradition is that it puts pressure on the king to ensure he has at least one surviving legitimate male heir before he dies. The urge to reproduce is an instinctual drive within humanity, as it is in any species, but in a family transferring sovereign power, continuation of the bloodline takes on an even greater significance. It is the king’s duty to produce ‘an heir and a spare’ (in case of the premature death of the eldest) to continue the legacy and maintain the prestige of his dynasty. Failure in this act has major repercussions – a succession crisis can lead to civil war affecting the entire population, and power might pass to another family, or even a rival kingdom.
Yet within a monogamous system in particular, the creation of heirs is limited by human reproductive biology. A queen can carry only one child at a time – discounting twins, which account for only a few per cent of pregnancies – and with high child mortality before the modern era, there was a significant chance that a king may die leaving only daughters or no surviving children at all. Then the future of the entire royal dynasty is at stake. Desperation over producing an heir was a main reason Henry VIII felt compelled to divorce or behead one wife after another. You could say, therefore, that his separation of the Church of England from the authority of the Pope was an effort to permit serial monogamy – functionally equivalent to polygyny but spread over time.66fn9
Within societies that permit polygyny, however, there is no such anxiety over a single queen bearing an heir. Henry VIII’s contemporary, Suleiman the Magnificent, sultan of the Ottoman Empire, had more than a dozen ‘legitimate’ children by his harem.67 And imperial harems often produced many more children than this. While a woman cannot typically produce more than about a dozen surviving offspring in her reproductive lifetime,fn1068 a king with access to a harem of women can achieve an extraordinary fecundity.fn11 The early-twelfth-century emperor Huizong holds the record for China: 65 children (including 31 sons who were mothered by twelve consorts) are named in the Song Shi, the official history of the Song Dynasty, although there were probably more – he was brought a new virgin at least once a week.71 The Ottoman sultan Murad III was survived by 49 children, and another seven of his concubines were pregnant when he died at the end of the sixteenth century.72 The late-eighteenth-century shogun Tokugawa Ienari holds the Japanese record with 52 children from his 41 concubines and sixteen consorts.73fn12
Royal families that reproduced polygynously rarely feared for their dynastic continuity, but without clear succession rules (such as primogeniture) in place, competition between potential heirs could quickly turn murderous.76 Within the early Ottoman Empire, for example, the death of the incumbent ruler served as the starting gun for a violent contest between the princes – a true Battle Royale – with the victor either killing all his rivals in battle or committing fratricide after securing the throne.77 When Mehmed III claimed the crown in 1595, for instance, he had all nineteen of his brothers murdered, along with every pregnant woman in his father’s harem. Pruning the royal family tree of contenders removed the risk of challenges to the throne. Such unsettled patterns of succession and the ensuing contests between potential heirs often created unstable interregnum periods after the death of each ruler; but a competitive scramble for the throne does at least constitute an exacting selective process. The prince who is able to rally the greatest support behind his own claim, or who demonstrates the most cunning and courage on the battlefield, has demonstrated the sort of qualities also needed in a supreme ruler.78
By the early seventeenth century, the Ottomans settled on a much less bloody solution to the biological problem of reproduction within the dynasty. The reigning sultan confined all his male relatives within the walls of the palace (a practice also adopted by the Mughal and Safavid dynasties in India and Iran respectively),79 where they lived comfortably but were forbidden from having children of their own80 – a true gilded cage. Agnatic seniority was also adopted, whereby the sultanship passed to the sultan’s eldest younger brother, and upon his death the next eldest, and only after all the brothers have died, to the eldest son of the first. Only the sultan was able to produce heirs – exerting reproductive control to preserve the stability of succession.81 As a result of the harem system, the Ottomans achieved a remarkable dynastic longevity – an unbroken chain of each sultan being succeeded by either his own son or the son of one of his predecessor-brothers, stretching over 600 years.82
Harems enabled rulers to maximise their own reproductive potential – and indeed, possession of a large harem was itself a status symbol – and so the Ottoman sultan in Topkapı Palace and the Chinese emperor in the Forbidden Palace, amid all their opulence and wealth, were no different in their fundamental biological motivation from a silverback gorilla sitting among his female mates and beating his chest to ward off rivals.
The operation of a harem for royal reproduction posed a potential problem, however. In polygynous animal species such as gorillas or lions, the dominant male keeps a careful eye over his harem of mates, fending off any potential rivals. In an imperial court, an emperor could not personally watch his harem, so he posted guards in the inner court. But how could he be sure that none of the guards would be tempted to have sex with the women himself? How could he be absolutely certain of the paternity of his children, and crucially his potential heirs, born of the harem? He could post several guards to watch each other, but that doesn’t stop them potentially colluding. The solution was to select only infertile men, or indeed men that had been made sterile: eunuchs. The creation of a sterile caste by castration – the removal of both testicles, and sometimes the penis as well – extends back to the first civilisations,83 but the word we use in English today, ‘eunuch’, derives from the Greek εὐνοῦχος, meaning ‘bedkeeper’, relating to their role as personal servants. The practice probably began with slaves who had little choice over the matter (as little as many of the women within the harem), but in China, eunuchs came to hold a revered position, and men volunteered for the honour.84
Such men-without-manhood came to serve many roles in imperial courts, not just as wardens of the harem but also as personal assistants, royal bodyguards and palace administrators, and beyond the palace as provincial governors, soldiers and military commanders.85 The fact that they were sterile, and often also forbidden from marrying, meant they had no investment in their own legacy or family loyalty.86 Eunuchs were therefore less likely to have ulterior motives, and so were believed to be more devoted and trustworthy servants of the royal court. Those in the inner sanctum of the harem occupied positions with unique access to the emperor, serving as confidant and counsel. And in palaces with a strict divide between inner and outer courts, the emperor didn’t communicate directly with his chief advisors; eunuchs would also serve as intermediaries.
By the tenth century in the Byzantine Empire, half of the administrative ranks in Constantinople were reserved solely for eunuchs, who often outranked the ‘bearded’ civil servants.87 In China, the sterile caste numbered around 10,000 in and around the Forbidden City in the 1520s, and this expanded over time so that by the end of the Ming dynasty in the early seventeenth century, the administration in Beijing contained a staggering 70,000 eunuchs, with another 30,000 distributed across the empire as government administrators and provincial governors.88
These imperial courts of history can be seen to resemble the hives of eusocial insects such as bees or ants. The emperor in the inner sanctum of the palace predominated over reproduction with a harem of mates and was surrounded by members of a sterile caste performing key roles both within the household itself and across the imperial dominion, as attendants, guards, administrators and military commanders. The gender roles are reversed, however: eusocial insects have a single queen at the centre of the colony, reproducing with a group of male drones and attended to by sterile female workers.
Let’s return now to the European monarchies operating within the cultural norm of monogamy. For those dynasties that tried to keep power within a close family, there was a biological sting in the tail.
CURSE OF THE SPANISH HABSBURGS
We saw earlier how the Habsburg dynasty had once been the master of strategic marriage, deftly constructing a web of family connections with the other great houses of Europe. The Habsburgs had also been biologically fortuitous, not only consistently producing male heirs (or at least numerous nephews and male cousins with strong succession claims) to secure the continuation of their own line but also often outliving rival families they’d married and inheriting their territories. But then the Habsburgs began to falter. You would expect a dynastic hiccup sooner or later simply from the balance of probabilities – a king dying young before he had been able to father an heir, a king or his wife being infertile – but the Habsburgs were unwittingly stacking the genetic deck against themselves.
While marriages into other ruling dynasties initially spread their influence, in order to prevent their prodigious political authority diffusing away and keep their empire intact they repeatedly married their own close relatives – cousin and cousin, or uncle and niece – especially for the line of kings (and far more so than did other royal houses). Yet while these consanguineous marriages reinforced their political power, such inbreeding consolidated defective genes within the family. Over the generations, the Habsburgs inflicted upon themselves a greater and greater hereditary burden. The means for their ascendency, therefore, also held the seeds of the catastrophic downfall of the Spanish Habsburgs, the branch of the family descending though Philip II.
The problem is genetic variation. When a child is conceived, it receives two copies of each gene, one from its mother’s egg and one from its father’s sperm. Sometimes, these gene copies, known as alleles, are defective – they have mutated and now produce a protein in the body that doesn’t function properly. But since mutations are rare, when a child does inherit a defective allele, the second allele is usually normal and thus able to compensate for the other. These hidden genetic abnormalities are called recessive deleterious mutations. Parents that are closely related to each other, however, will likely already share many of the same gene variants, and so the chances of the child being dealt two defective copies of the same gene are much higher. The effects of the mutation are no longer masked and become manifest as genetic disorders or congenital defects.
Consanguineous pairings create overlaps in the family tree, with certain individuals playing what would be two roles in a typical family structure. For example, in a marriage of first cousins, the children have only three different sets of great-grandparents rather than four. This common ancestry means fewer alleles being contributed to the child’s genetic mix, increasing the chances of two defective alleles of the same gene being paired up and causing problems. The probability that the child inherits two of the same alleles of any gene because of this common ancestry is one-sixteenth (0.0625), and so the inbreeding coefficient is 0.0625.fn13 This decrease in genetic variation is less significant with pairings of less closely related individuals, such as between second cousins, but if such consanguineous unions are repeated generation after generation, the inbreeding coefficient still mounts greatly.fn14
An ideal family tree for a child, with good outbreeding (the opposite of inbreeding), looks like a neat branching diagram with eight great-grandparents at the top. But the Habsburg genealogy came to resemble a tangled bush with branches crossing over and even fusing together (in cases where an uncle married his own niece). Out of the 73 marriages entered into by both the Spanish and the Central European branches of the Habsburg dynasty until 1750, there were four uncle-niece pairings, eleven between first cousins, four between first cousins once removed, eight between second cousins and many others among family members more distantly related. Marriages between close kin were especially common among the Spanish Habsburgs: out of a total of eleven marriages in the line of kings, nine were consanguineous unions (third cousins or closer), including two uncle-niece and one first cousin marriage.91 This increased the degree of inbreeding tenfold over the two centuries separating the founding of this branch of the family, with Philip II, to Charles II, the last Habsburg king of Spain, who had an inbreeding coefficient of 0.254 – even greater than the progeny of a directly incestuous parent-child or brother-sister pairing.fn15
The most conspicuous trait of the dynasty was evident in the distinctive Habsburg countenance. Already prominent with Holy Roman Emperor Charles V, in the early 1500s, but becoming more and more extreme over the following generations, was a long, humped nose with an overhanging tip, and a drooping, bulbous lower lip.92 Leopold I, reigning as the Holy Roman Emperor in the second half of the seventeenth century, was referred to by the Viennese as ‘Fotzenpoidl’ on account of his grotesquely swollen lips.93 (Fotze is a particularly crude German word for vagina, and so ‘Fotzenpoidl’ could be translated as ‘twat-face’.) But, in particular, members of the dynasty became characterised by their sharply jutting lower jaw, which was so pronounced that the upper and lower rows of teeth didn’t meet; it became known as the Habsburg jaw.94
Facial surgeons have analysed portraits of the Habsburg dynasty, focussing on 66 paintings where it can be ascertained that the artist had personally seen the subject, meaning the depiction can be considered reliable, and rated the degree of deformity of the mandible bone of the lower jaw. Comparing these ratings against the calculated degrees of inbreeding for the members of the dynasty confirmed that the protruding Habsburg jaw is indeed correlated with increasing inbreeding, and that it is caused by the effects of recessive genes.95
But a deformed jaw was not the only affliction of the Habsburgs. The dynasty came increasingly to suffer epilepsy and other mental issues, generally sickly children, and strings of miscarriages and still-births.96 Of the 34 children born into the Spanish branch of the Habsburgs between Charles V and Charles II, ten of them died within their first year and a further seventeen before their tenth birthday – an overall infant mortality of 80 per cent.97 Here was one of the most privileged and pampered families on earth, with access to the best nutrition, lifestyle and medical attention available at the time, yet they were suffering child death rates four times higher than Spanish peasant families living in rural villages.98 Of those who survived, many were inflicted with not just the infamous drooping lip and jutting Habsburg jaw, but a range of other physical deformities.
Matters came to a head with the ascent of Charles II in 1665. So severe were his many afflictions that he came to be known as El Hechizado, ‘The Hexed’.99 Contemporary reports describe the baby Charles as weak and big-headed. He was unable to speak until aged four or walk until he was eight; the frail child was constantly carried around by a nurse. Charles suffered swelling of his feet, legs, abdomen and face, and his mouth was filled with an overlarge tongue. He showed very little interest in his surroundings – a medical condition known as abulia – and suffered fits of epilepsy. He regularly urinated blood, had intestinal problems and was afflicted with diarrhoea and vomiting.100 The British envoy Alexander Stanhope wrote, Charles II ‘has a ravenous stomach, and swallows all he eats whole, for his nether [lower] jaw stands so much out, that his two rows of teeth cannot meet. To compensate which, he has a prodigious wide throat, so that a gizzard or liver of a hen passes down whole, and his weak stomach not being able to digest it, he voids it in the same manner.’101 In his final years, the king could barely stand, and suffered from hallucinations and convulsions.102
Charles II suffered such a litany of afflictions that they were almost certainly due to not just one genetic disease, but a whole suite of inherited disorders, rooted in generations of consanguineous marriages. Each individual can have up to a total of 24 great-grandparents and great-great-grandparents combined – but Charles II had only sixteen.103 Similar figures recurred throughout his ancestry. Charles’s mother was the niece of his father, and his grandmother was also his aunt. The Habsburg gene pool had become very shallow and stagnant indeed.
Charles was only three years old when his father died, and so his widowed mother was appointed as the Queen Regent to rule on his behalf, aided by personal ministers. This arrangement was restored when it became abundantly clear that even as a legal adult Charles was incapable of ruling the empire, and on his mother’s death in 1696, his second wife took over the mantle.104 The only critical task needed of the pitiful king was that most natural and innate of human functions – to reproduce. Yet although Charles was married twice, no children resulted from either union. His first wife spoke of his premature ejaculation; the second complained about his impotence.105 It seems that Charles was congenitally unable to father any children. The generations of inbreeding and mounting recessive disorders had finally collapsed. The Spanish Habsburg dynasty was doomed before its last king had even been born.
As Charles II neared death without an heir at the end of the seventeenth century, his branch of the Habsburg dynasty faced extinction, ending its two centuries-long rule over Spain and its extensive overseas possessions. Attempts by the French and English to negotiate a partitioning of the Spanish Empire to maintain stability and a balance of power were rejected by the Habsburgs, who wanted to see their empire preserved intact. Charles II stubbornly insisted that the empire be inherited ‘without allowing the least dismemberment nor diminishing of the Monarchy founded with such glory by my ancestors’.106 Consequently, within months of the death of Charles II in 1700, the War of the Spanish Succession engulfed the continent and raged as ferociously in the colonies in the West Indies and French Canada.107 By its conclusion in 1714, the conflict had fundamentally shifted the political landscape of Europe and the world. The French prince Philip of Anjou was crowned Philip V of Spain, retaining much of the empire; the Dutch Republic had effectively been bankrupted by the war; and Britain, having established its naval superiority, began its ascent as the dominant commercial power.fn16
Over the last 200 years, nation states have increasingly shifted from rule by monarchy to republics and representative democracies, with the transition of power proceeding either gradually or by violent revolution. Today, of almost 200 independent states around the world, only around twenty monarchies remain, and on the whole their role is ceremonial.108
Rule by kingship was once intimately tied to kinship. Now, transmission of ruling power through inheritance has virtually disappeared, but the influence of family and dynasty still persists even within modern democracies. While political office is no longer hereditary, the members of political dynasties benefit from significant advantages over newcomers. Their surnames are already familiar to the electorate, they are able to draw on established networks of supporters and financial backers, and they often already have substantial familial wealth.109
Within India, the largest democracy in the world, political families have dominated the government since independence. In 2009, nearly a third of the elected members of parliament had relatives serving in public office at the same time or immediately preceding them.110 Kinship is also particularly strong in the politics of Japan, South Korea, Thailand and Indonesia.111 In the United States, two presidents have had sons become president: John Adams (1797–1801) and then John Quincy Adams (1825–1829); and then more recently George Bush (1989–1993) and George W. Bush (2001–2009). The Taft, Roosevelt and Kennedy families all also occupied the White House, as well as numerous other prominent elected government offices over a century or more. Nor are modern democracies immune to nepotism – within President Trump’s administration (2017–2021), for example, both his daughter and son-in-law were appointed to prominent government posts.112
Family businesses have also been common through history, and dynastically inherited companies remain a significant part of today’s economy. Large corporations today owned or led by multiple generations of the same family include major banks (Barings, Rothschild, Morgan), car manufacturers (Ford, Toyota, Michelin) and many other familiar firms including Heineken, Ikea, Levi Strauss and L’Oréal. The process of generational handover, with an elderly CEO refusing to step down or rivalry between siblings to take over the leadership, can be as turbulent as anything seen historically with royal succession.113
The origins of the human family are ancient, but their influences on our life today are as strong as they have ever been.
Another constant of human life is our vulnerability to infectious diseases, and we’ll turn now to their history-defining effects.