Be fruitful and multiply
Suggestion or command?
A recent study of monogamy in various species found that we humans are among the most monogamous of our fellow mammals. “There is a premier league of monogamy, in which humans sit comfortably, while the vast majority of other mammals take a far more promiscuous approach to mating,” said Mark Dyble, an evolutionary anthropologist (and soccer fan, apparently) at the University of Cambridge, who conducted the study.
Morality aside, there is a reason for this. Because we have big brains, we have to be born prematurely, compared with most other mammal species. This means we are peculiarly vulnerable for a long time and in need of watchful parenting. Moreover, after we developed culture, our offspring required additional time to absorb the ways of our tribes and clans. Two parents could carry this burden better than one. As a result, monogamy made selective sense.
But so did cheating if done discreetly. A man who could get another man unknowingly to raise his child won a bonus in the competition to transmit genes to the next generation. So did a woman who got her man to raise a child fathered by someone else with better genes.
Thus monogamy with exceptions became the norm among humans. We are more monogamous than meerkats and less monogamous than beavers.
Yet we are singular in one behavioral aspect that made Dyble’s study more complicated. To determine rates of monogamy, he tested the DNA of siblings to determine if they had the same parents. By this means he could distinguish full siblings from half-siblings. If two-thirds of siblings were full, that species was assigned a monogamy rate of 66 percent.
This rule was only approximate for humans, who are the sole species known to practice deliberate contraception. Cheating humans want extra sex but not usually extra children. For most of our evolutionary history, extra children were a statistically predictable consequence of extra sex. Less so in modern times.
Dyble conceded the difficulty. “This study measures reproductive monogamy rather than sexual behaviour,” he said. “In most mammals, mating and reproduction are tightly linked. In humans, birth control methods and cultural practices break that link.”
So we humans should be careful about bragging to meerkats on our monogamy.
There’s a larger issue, of greater historical importance. We humans are the first species to voluntarily reduce our birth rate to the point where an overall population decline is in prospect. Population declines have happened in many species over time, but in response to disease, overpredation, habitat destruction or other external stress. A voluntary decline is unheard of.
Why are we doing it?
Some individuals and couples who choose not to have children say they can’t bear to bring children into a world as discombobulated as ours has become. Some point to the environmental damage humans have done and argue that a smaller human population will diminish the damage. For such as these, not having children is a moral choice.
What’s the flip side of this argument? Is there a moral obligation to have children? The author of the book of Genesis, or the God for whom he spoke, said there is, or at least was back then. “Be fruitful and multiply” is the King James transcription. But was that an order or merely a recommendation?
Historically it has been read as both. Many believers in the Bible interpreted it as giving them domain over the earth and its other species. The world was there for human taking.
This doesn’t get nonbelievers very far. For them, is there a moral imperative to carry forward a species that goes back 10,000 generations? If everyone today decided not to have children, the human race would go extinct within a century. Would that be a betrayal of all those generations that got us to where we are today? Would it be a denial of the possibility of future human progress? Do humans today have moral obligations to humans past and humans future?
Most cultures have taught that we have obligations to our forebears. We must honor and care for them while they are alive, as they gave us life and cared for us when we could not care for ourselves. Many cultures tend the shrines of ancestors after they die. In Western culture we visit their graves, adorning them with flowers. We erect statues to those of particular accomplishment. We name cities and states after some of them.
Obligation to humans not yet born is a trickier question. Given that reliable contraception is relatively new, measured against the history of our species, we haven’t had a chance to develop cultural reflexes on the subject. We’ve only begun to weigh the alternatives to having as many children as resources allow.
Fortunately, we’ll have time to think about it. The human population might shrink in the next century, but it’s not going to disappear. The last human, if there is one, won’t be born for a while yet.
There is a whole different theory, please read “Sex at Dawn” by Christopher Ryan and Cacilda Jetha. Humans were polyamorous, we lived in small groups (or large families). Paternity Certainty was not important, each child belonged to “the family”. Your statement “Two parents could carry this burden better than one” is replaced by “the tribal group shares the burden”. It takes a village.
According to this theory, monogamy came about recently, when private property came about, as a result of the Agricultural Revolution. The men in charge wanted to leave their goats and wheat fields to THEIR offspring. Thus women were subjugated and the patriarchy was established. Check out the Bible, there is nothing in there about monogamy. The high-value men had their many wives (not to mention their slave concubines).
Another thought-provoking post, Bill. My wife & I have been dealing with infertility struggles over the last year (doctors believe it’s linked to my father-in-law’s exposure to Agent Orange in Vietnam), so this topic has been fresh on our minds.
It’s especially interesting that even though childbearing has historically been such a large part of the culture in Utah, the younger generations (Millennials & Gen Z) are starting to buck that trend. Dallin H. Oaks—the new president of The Church of Jesus Christ of Latter-day Saints—actually addressed the topic of demographic decline in his most recent address:
“The family proclamation, announced 30 years ago, declares that ‘the family is ordained of God’ and ‘is central to the Creator’s plan for the eternal destiny of His children.’ It also declares ‘that God’s commandment for His children to multiply and replenish the earth remains in force.’ And ‘we further declare that God has commanded that the sacred powers of procreation are to be employed only between man and woman, lawfully wedded as husband and wife.’ …
“In the United States we are suffering from a deterioration in marriage and childbearing. For nearly a hundred years the proportion of households headed by married couples has declined, and so has the birthrate. The marriages and birthrates of our Church members are much more positive, but they have also declined significantly. It is vital that Latter-day Saints do not lose their understanding of the purpose of marriage and the value of children. That is the future for which we strive.
“The national declines in marriage and childbearing are understandable for historic reasons, but Latter-day Saint values and practices should improve—not follow—those trends.”
Many of my peers from high school have decidedly turned against procreating in their marriages. I’m struggling to grasp exactly why. However, there does seem to be a link between grad school, political affiliation, and their lack of church attendance now that they’re adults. Basically, the conservatives have/are trying to have kids, and the liberals aren’t. I’m interested to see the results of the 2030 Census, because UT & SD were the only 2 states with fertility above replacement rate in 2020 (Utah’s population grew 20% from 2010-2020), but I’d like to see a breakdown showing how much of that is from natural increase, and how much is from people moving to Utah.