If we could survive without a wife, citizens of Rome, all of us would do without that nuisance.” So proclaimed the Roman general, statesman, and censor Quintus Caecilius Metellus Macedonicus, in 131 B.C. Still, he went on to plead, falling birthrates required that Roman men fulfill their duty to reproduce, no matter how irritating Roman women might have become. "Since nature has so decreed that we cannot manage comfortably with them, nor live in any way without them, we must plan for our lasting preservation rather than for our temporary pleasure."
With the number of human beings having increased more than six-fold in the past 200 years, the modern mind simply assumes that men and women, no matter how estranged, will always breed enough children to grow the population -- at least until plague or starvation sets in. It is an assumption that not only conforms to our long experience of a world growing ever more crowded, but which also enjoys the endorsement of such influential thinkers as Thomas Malthus and his many modern acolytes.
Yet, for more than a generation now, well-fed, healthy, peaceful populations around the world have been producing too few children to avoid population decline. That is true even though dramatic improvements in infant and child mortality mean that far fewer children are needed today (only about 2.1 per woman in modern societies) to avoid population loss. Birthrates are falling far below replacement levels in one country after the next -- from China, Japan, Singapore, and South Korea, to Canada, the Caribbean, all of Europe, Russia, and even parts of the Middle East.
Fearful of a future in which the elderly outnumber the young, many governments are doing whatever they can to encourage people to have children. Singapore has sponsored "speed dating" events, in hopes of bringing busy professionals together to marry and procreate. France offers generous tax incentives for those willing to start a family. In Sweden, the state finances day care to ease the tension between work and family life. Yet, though such explicitly pronatal policies may encourage people to have children at a younger age, there is little evidence they cause people to have more children than they otherwise would. As governments going as far back as imperial Rome have discovered, when cultural and economic conditions discourage parenthood, not even a dictator can force people to go forth and multiply.
Throughout the broad sweep of human history, there are many examples of people, or classes of people, who chose to avoid the costs of parenthood. Indeed, falling fertility is a recurring tendency of human civilization. Why then did humans not become extinct long ago? The short answer is patriarchy.
Patriarchy does not simply mean that men rule. Indeed, it is a particular value system that not only requires men to marry but to marry a woman of proper station. It competes with many other male visions of the good life, and for that reason alone is prone to come in cycles. Yet before it degenerates, it is a cultural regime that serves to keep birthrates high among the affluent, while also maximizing parents' investments in their children. No advanced civilization has yet learned how to endure without it.
Through a process of cultural evolution, societies that adopted this particular social system -- which involves far more than simple male domination -- maximized their population and therefore their power, whereas those that didn’t were either overrun or absorbed. This cycle in human history may be obnoxious to the enlightened, but it is set to make a comeback.
THE CONSERVATIVE BABY BOOM
The historical relation between patriarchy, population, and power has deep implications for our own time. As the United States is discovering today in Iraq, population is still power. Smart bombs, laser-guided missiles, and unmanned drones may vastly extend the violent reach of a hegemonic power. But ultimately, it is often the number of boots on the ground that changes history. Even with a fertility rate near replacement level, the United States lacks the amount of people necessary to sustain an imperial role in the world, just as Britain lost its ability to do so after its birthrates collapsed in the early 20th century. For countries such as China, Germany, Italy, Japan, and Spain, in which one-child families are now the norm, the quality of human capital may be high, but it has literally become too rare to put at risk.
Falling fertility is also responsible for many financial and economic problems that dominate today's headlines. The long-term financing of social security schemes, private pension plans, and healthcare systems has little to do with people living longer. Gains in life expectancy at older ages have actually been quite modest, and the rate of improvement in the United States has diminished for each of the last three decades. Instead, the falling ratio of workers to retirees is overwhelmingly caused by workers who were never born. As governments raise taxes on a dwindling working-age population to cover the growing burdens of supporting the elderly, young couples may conclude they are even less able to afford children than their parents were, thereby setting off a new cycle of population aging and decline.
Declining birthrates also change national temperament. In the United States, for example, the percentage of women born in the late 1930s who remained childless was near 10 percent. By comparison, nearly 20 percent of women born in the late 1950s are reaching the end of their reproductive lives without having had children. The greatly expanded childless segment of contemporary society, whose members are drawn disproportionately from the feminist and countercultural movements of the 1960s and 70s, will leave no genetic legacy. Nor will their emotional or psychological influence on the next generation compare with that of their parents.
Meanwhile, single-child families are prone to extinction. A single child replaces one of his or her parents, but not both. Nor do single-child families contribute much to future population. The 17.4 percent of baby boomer women who had only one child account for a mere 7.8 percent of children born in the next generation. By contrast, nearly a quarter of the children of baby boomers descend from the mere 11 percent of baby boomer women who had four or more children. These circumstances are leading to the emergence of a new society whose members will disproportionately be descended from parents who rejected the social tendencies that once made childlessness and small families the norm. These values include an adherence to traditional, patriarchal religion, and a strong identification with one’s own folk or nation.