The end of humanity?

A speculative history of the future

For most of human existence, sex and procreation were inescapably connected. There were exceptions, of course. Not every sexual coupling involved a man and a woman, and not every heterosexual coupling produced a baby. But the connection was strong enough that the perpetuation of the species didn’t require sexual partners to make a separate decision to have children. Their lust drove them to have sex, and babies naturally followed.

The development of reliable methods of contraception broke the link. Now it was possible to have sex without having children. On the positive side, this meant that children, more often than before, were conceived deliberately rather than accidentally. Presumably this improved the post-natal experience of the young ones, as a group if not in every case.

On the negative side, the breaking of the link between sex and procreation raised the possibility that not enough decisions to have children would be made to keep the species afloat. Humans had evolved to like sex; they hadn’t evolved, at least not so dramatically, to like children. Sexual passion has started wars, inspired art, driven men - in particular - to feats bold and foolhardy. Fondness for notional children – those who don’t yet exist - is a more subtle emotion and less ubiquitous, especially among males. 

So the question was, would enough people choose to have babies often enough to sustain the human population?

History offered little direct guidance, since the issue only arose in the second half of the twentieth century, after a million years or so of being a non-issue. Humans had been trying to manipulate the birth rate for a long time, most often with the goal of increasing it. Norms and laws against masturbation and homosexuality aimed to channel sexual energies in a procreative direction. Laws against abortion had the same purpose. At the individual level, couples whose attempts at conception fell short turned to herbs, potions and prayers to improve fertility and virility.

Only after societies began to industrialize did couples in sizable numbers attempt to limit the numbers of births. On preindustrial farms, extra hands were almost always a blessing - that is, an asset rather than a liability. Children can do farm work from an early age, covering their own cost of maintenance and producing a bonus for the family. Moreover, before industrialization, high mortality rates among infants and children meant that lots of births were necessary to ensure a sufficient number survived to adulthood.

But numerous births were not such a blessing after industrialization. Especially in countries that outlawed child labor in factories and mines, kids were a net burden until they were almost adults, at which point their earnings didn’t automatically go to the family. And as improvements in public health reduced the mortality rate of the youngsters, fewer births were needed to guarantee the survival of enough of them to support their parents in the latter’s old age.

Contraceptive methods before the mid-twentieth century were rudimentary and uncertain. Abstinence was effective but hard to maintain. Condoms were clumsy or expensive.

The introduction of oral contraceptives changed the situation dramatically. The sexual revolution of the 1960s was an immediate result; a definitive decline in the birth rate followed. The American birth rate fell by forty percent between 1960 and 1980 and kept falling afterward.

Another factor discouraging births was the broader entry of women into the paid workforce, although this might have been a consequence as a much as a cause of the decline in fertility. In most traditional cultures, women were supported economically as parts of families, which were typically headed by men. Women in families gained much of their importance from the bearing and rearing of children. The idea that a woman could flourish outside a family was novel and often threatening. This changed when women began drawing paychecks of their own. They no longer needed husbands for economic security, and though some women did have children without husbands, the net result was an additional decline in births.

Countries like the United States that attracted immigrants kept growing in population, despite the fall in their birth rates. But many other countries - including Japan and several in Europe - experienced and projected steady declines in overall numbers. 

This raised unprecedented challenges. Particular countries and regions had lost population at times in the past as a result of catastrophe - the Black Death of the fourteenth century, the world wars of the twentieth. China in the 1970s and 1980s adopted a one-child per couple policy to contain growth the government considered alarming, but that policy had to be imposed from above and was much resented, to the point of repeal in the 2010s. On the whole, the experience and prospect of persistent, deliberate population decline was a new experience for the human race.

What would be the consequences?

A negative one was strain on social-economic models based on lots of workers and few retirees. The solvency of America’s Social Security system depended on many workers making modest contributions to a general fund from which a smaller number of pensioners received larger checks. The shortfall in babies would eventually become a shortfall in workers relative to pensioners, compelling larger contributions from the former, small checks to the latter, or both.

A positive effect might be reduction in human damage to the earth’s environment. Fewer people meant fewer exhaust-spewing cars, fewer ozone-depleting airplane flights, fewer methane-belching cows, fewer buildings and highways constructed with carbon-profligate concrete, and so on. Some fans of negative population growth fondly imagined a return to a pre-human Eden.

Yet if population decline persisted, countries might take action to halt it. In the past, nations had sometimes gone to war to revive declining populations. American Indian tribes suffered population crashes after exposure to European and African diseases; more than a few responded by raiding other tribes and white settlements for women and children, who were forcibly inducted into the tribes.

Other responses might be less drastic. Governments could offer financial incentives to couples to have children; indeed some in the early 2020s were already doing so. Rich countries could entice immigrants from poor countries with offers of jobs and citizenship. This approach was the engine of much migration in the past; America’s industrialization was built on the labor of poor immigrants from Europe and Asia.

Yet immigration required emigration, and if declining population became a global phenomenon, merely crossing borders would do nothing to change the overall condition.

It was hard to see how the downturn in fertility might be reversed. Americans of the Baby Boom generation often remembered their large families fondly, but the Boomers’ children seemed quite content with one or two kids on whom to lavish attention and expense. And these children, having normalized their experience, couldn’t imagine doing less for their own kids. Evolving standards had made large families too expensive.

If populations continued to decline, once-inhabited places might revert to nature. Large portions of the American Great Plains today hold many fewer people than they did a century; homesteads and hamlets lie abandoned by the many thousands. A move is afoot to return part of the prairie to the buffalo. In Japan, villages disappear as old residents die and no one comes to take their place. It’s not out of the question that whole countries might eventually vanish from the map, perhaps absorbed by neighbors. Great cities and empires of the past have vanished; it could happen again.

The end of it all? Perhaps there would be no end, only a recycling of earlier growth, triggered by social or political shocks or scientific developments. Perhaps babies could be cloned –manufactured, as it were. But someone would still have to tend the children – unless robots assumed the task. History offers little insight into such a future.

Another outcome could be that the humans of some distant, numerically diminished generation might decide that Homo sapiens had had a good run and call it quits. Extinction comes to most species sooner or later; perhaps it would be more noble to embrace that end with dignity.

Every so often we read about the last speaker of some once thriving language, of the last keeper of a tribe’s cultural traditions. Imagine being the last human on earth, looking back over thousands of years of the history of the species, and looking forward to – nothing. “To sleep, perchance to dream,” says Hamlet. Or perchance not.

So, what do you think? Would humans ever say enough is enough? Or would they keep struggling? What would you do? Comment here: