August 10, 2013
Natural Selection To Boost Fertility In Developed Countries

Jason Collins and Oliver Richards expect a resurgence on fertility in developed countries.

We propose that the recent rise in the fertility rate in developed countries is the beginning of a broad-based increase in fertility towards above-replacement levels. Environmental shocks that reduced fertility over the past 200 years changed the composition of fertility-related traits in the population and temporarily raised fertility heritability. As those with higher fertility are selected for, the “high-fertility” genotypes are expected to come to dominate the population, causing the fertility rate to return to its pre-shock level.

This is not really new news. Delayed child-bearing and other attributes are being selected against. Natural selection sped up reproduction among French Canadians.

Africa is a continent whose demographic trends already do not fit the Panglossian projections of some commentators about how we've supposedly licked the overpopulation problem. In the next 90 years Africa's population will go up by more than a factor of 4. Quadrupling. Good bye many species of plants and wildlife.

The new statistics, based on in-depth survey data from sub-Saharan Africa, tell the story of a world poised to change drastically over the next several decades.

Take a look at Tanzania, which is today one of the poorest countries in the world. As of 2000, it had 34 million people; California’s population was the same that year. Today, Tanzania has about 45 million people. By 2100, its population is projected to be 276 million – almost the size of the entire United States today, and by then one of the largest countries in the world.

The whole world is on course for a huge resurgence in fertility. Natural selection assures this outcome. The only way I can see to prevent it: government-mandated genetic engineering of offspring to reduce the next generation's desire to have kids. But I doubt that will happen.

One of the reasons I am not optimistic about the future is natural selection. Selective pressures are more powerful than our conscious minds. The part of our minds that thinks it controls the speech center is deceived into thinking it is in charge. Our conscious minds do far more rationalizing and far less rational reasoning than we think we do. I give us poor odds of getting in control of our instincts and curbing their most damaging manifestations.

Share |      Randall Parker, 2013 August 10 01:10 PM 

Abelard Lindsey said at August 10, 2013 2:09 PM:

New meaning to the expression "Fear of a Black Planet".

Acksiom said at August 10, 2013 2:22 PM:

>The only way I can see to prevent it: government-mandated genetic engineering of offspring to reduce the next generation's desire to have kids.

What about the coming RISUG/Vasalgel revolution in male birth control? They're expecting FDA approval for market release in the usa by 2015. I'm confident that a 99+% reversible MBC injection with a 10-year lifespan will be more than popular enough to throw off all their predictions. Did they mention that at all?

James Bowery said at August 10, 2013 4:32 PM:

Twelve Monkeys

Abelard Lindsey said at August 10, 2013 8:37 PM:

Twelve Monkeys?

Seriously? Do you really wanna do it?! Do ya?

James Bowery said at August 10, 2013 9:35 PM:

No, actually. I don't. What I want to do is get eusocial humans out of the biosphere and enforce individual sovereignty on all humans who remain in the biosphere -- eliminating human eusociality from the biosphere is the only way humans and the biosphere can coexist.

However, if something like this can't be worked out the I suspect Twelve Monkeys will be inevitable.

Anthony said at August 11, 2013 7:16 AM:

Prosperity is the great prophylactic!
As people earn more, they have fewer children.
As nations develop a social safety net, their people don't have to conceive 12 children as insurance for old age.

James Bowery said at August 11, 2013 7:32 AM:

We need a name for Anthony's religion.

Engineer-Poet said at August 11, 2013 8:25 AM:

Sadly, "prosperity gospel" is already taken.

Acksiom said at August 11, 2013 10:58 AM:

I'm consistently amazed at how deliberately and willfully blind people will be to anything even remotely connected to men's liberation.

James Bowery said at August 11, 2013 11:04 AM:

Whatever it is, E. O. Wilson, for all his anti-religious posturing, is a devotee to the same religion.

Randall's diagnosis "Our conscious minds do far more rationalizing and far less rational reasoning than we think we do." is apt even for such supposed paragons of rationality as E. O. Wilson.

José said at August 11, 2013 12:04 PM:

There are so many unsubstantiated assumptions here it's nauseating. We know too much about evolution to go on crediting wild hypotheses that offer no biochemical mechanism. An evolutionary hypothesis in 2013 that has no biochemical reality behind it is worthless pabulum fit for the pages of popular science magazines. This hypothesis depends on a genetic basis for the desire to have children, when it has not even been shown that people have such a biological drive in the first place. People have a sexual drive, but with contraception that is clearly distinguishable from a drive to reproduce as such. Consider this contrary hypothesis: people have no such biological drive, because in the natural condition of our ancestors, sexual drive would have rendered any separate drive to produce offspring redundant. In fact, sexual drive is the manifestation of the selective pressure to reproduce on the individual's behaviour. Sexual drive has a sound and well-documented biochemical basis, and since it would clearly have sufficed for the purpose of promoting procreation, Occam's razor and parsimony in general favour this hypothesis. In such a case, what is the substrate on which selection will act to increase fertility?

This tendency to generate baseless Adaptationist hypotheses for everything has left the science of biology far behind while abusing its language for credibility. I invite anyone who may be hyperventilating over this or any other such hypothesis to come down to reality and return to the facts.

Brett Bellmore said at August 11, 2013 12:53 PM:

"In such a case, what is the substrate on which selection will act to increase fertility?"

I agree that there's no particular reason to suppose we have a specific drive to reproduce, as opposed to a drive to have sex, and then to take care of the resulting children. However, that doesn't preclude evolutionary modulation of the rate of reproduction: Since sex leads to reproduction unless birth control is used reliably, all you'd need to do is evolve more careless/stupid people, who'd more often screw up their efforts to use birth control.

Welfare programs have pretty much abolished the evolutionary pressure against stupidity, so it's not like the resulting offspring would starve.

Alank said at August 11, 2013 2:07 PM:

It is not unreasonable to imagine the development of increasingly effective forms of birth control for men and women. The question of course is how willingly would people use the methods.

Or increasing economic misery may limit population growth. Unfortunately the key word is "misery."

Anthony's point about the impact of prosperity is well known from the population trends among prosperous people in the U.S. and Europe, as I understand it. The problem is, there is no reason to expect an overwhelming surge of prosperity among the 5.9 billion now living in developing countries.

Jose is getting a little overly fixed on biochemical mechanisms. Much human and other animal behavior is reasonably deduced by observing the species, not by relying on chemistry. Humans and other animals obviously choose to nurture and raise their young, not merely have sex. It is the pattern of behavior of animals with a drive to reproduce.

To Randall and to James Bowery (and anyone else): what about a modified version of 12 Monkeys? What about a virus that moderates but does not eliminate human fertility? Sorry if that sounds presumptuous, but then, a global population of almost 11 billion by 2100 is kinda unreasonable, too.

Here is the UN revised forecast, by the way, if you go to this page and click on the "World Population Prospects" item under the "What's New" header:

Starsign Galaxy said at August 11, 2013 2:47 PM:

Alank wins best comment award to this point.

Alank is right that most of the 6 billion impoverished world denizens are still impoverished for a good reason. Citizens of dictatorships such as North Korea or Cuba, may be eligible for prosperity as soon as they slip their leashes.

Jose must not know many women if he thinks there is no human drive to reproduce. Men just want to spread their seed. Women are different. They are largely compelled to reproduce.

Alank's idea for a virus that severely slashes human fertility without eliminating it is not a new idea. In the scifi novel Tuf Voyaging, , Haviland Tuf used that very idea to prevent a ruinous interstellar war.

A global economic collapse may limit population growth as Alank posits. The depressing effect on birth rates would be greater in the developed world than in the undeveloped world. Changes in death rates may balance that effect.

James Bowery said at August 11, 2013 4:18 PM:

Alank, think about antibiotics and bacteria. Antibiotics reduce the population of bacteria. If we're lucky, antibiotics eliminate enough bacteria that the immune system cleans up the remainder. We don't need to go into antibiotics abuse as a red-herring issue here to see that it is plausible that even without antibiotics abuse, bacteria will probably evolve resistance to antibiotics given enough time.

The principle of economic development, or introduction of birth control technology, or anything else, operates under the same laws: The laws of mutation and selection.

Exponential growth is a "power"ful arithmetic driver so you don't need to have very many people evolve a resistance to the fertility-inhibiting effects of anything least of all prosperity (which includes all the key ingredients for biological reproduction).

Jehu said at August 11, 2013 5:59 PM:

Homeschooling seems to be a very effective 'evolved' resistance to fertility-inhibiting effects of modernity. Just ran into a young lad who got married a few years ago around 17 or 18 years of age. He and his wife are expecting their third I believe now, while in their low twenties. I've got three children myself, but I'm over 40 now. He and his wife will probably have at least 4, perhaps even 6 or more. The future belongs to those who show up for it.

James Bowery said at August 11, 2013 6:54 PM:

Jehu, be careful of discounting evolution with scare quotes. For example, a girl who was raised in a deep-background Mormon family I know is now at the end of her fertile years, having performed with Cirque Du Soleil from her college graduation until about 30 years of age. She has ended up struggling as a "performance artist" in Brooklyn preaching the gospel of New York City's diversity with all the fervor of Church Lady as she asks "Well well well, isn't that special? Could it be.... HITLER???" She she has passed from one religion to another due to her high IQ not being inadequately addressed by her parents' religion in an era when Jews have made up a new religion, Holocaustianity, to displace JudeoChristianity. She will have no children. What is going on with many people is a heritable indocrinability -- a susceptibility to memes handed to them from outside their immediate families by those who manage to occupy the current zeitgeist's equivalent of a pulpit. At one time those occupying that pulpit enhanced fertility via the doctrines of the LDS and frontier America applied to high intelligence, talent, physical health and attractiveness. Now, however, that same indoctrinability, high intelligence, talent, physical health and attractiveness is the route for Holocaustianity to sterilize them.

People who home school may have almost all the same characteristics of such Mormons except the tendency to recklessly respect the "pulpit" whether it be at the front of a church or at the front of a movie theater.

Jehu said at August 11, 2013 9:30 PM:

I say 'evolved' because its a social evolution not something that is the result of normal animal husbandry/selection/whatever you prefer to call it. Homeschooling is a strategy to reduce the amount of Cathedral indoctrination your children suffer and to increase their effective fertility. As an incidental, it also provides a genuine education. I do agree that ease of indoctrination is something that is pretty heavily genetically influenced (I think it's a U shaped curve with the peak around 110-125 or so IQ and increases strongly with Agreeableness). So to some extent we're also selecting from low agreeableness.

Randall Parker said at August 11, 2013 11:21 PM:

The Amish have developed a culture immune to the fertility-suppressing effects of modernity. They are not the only group to have done so.


There are genetic variants that alter fertility. The selective pressures for higher fertility are strong. Since there is a genetic component to religiosity and religious people have more kids that's another way to demonstrate a genetic component to fertility.

José said at August 12, 2013 1:28 AM:

Randall Parker,

Genetic variants that alter fertility do not in any way counter the point I was making unless they alter fertility through some behavioural mechanism that is independent of sexual drive. You offer no evidence for this. Notably, the French Canadian data-set ends in 1940, prior to the widespread use of contraception. As for a genetic component to religiosity, the twin study is inadequate to demonstrate such a finding. Among other alternate interpretations, it could be that intelligence is the variable being sampled. There is considerable evidence that less intelligent people are more religious. There are other possible, and poorly studied, confounding variables including physical attractiveness. You could of course say that selection is acting to increase fertility by reducing intelligence. Other respondents proffered that as an answer to my post, but then you're just making the "dysgenic fertility" observation that has existed for centuries.

Vektor said at August 12, 2013 5:39 AM:

A global economic collapse would have the effect of disrupting the welfare state. There would be chaos, but the population would go down as people would have to fend for themselves. Natural selection is context sensitive - change the context. I think we are at a point now that, only an economic collapse can disrupt the welfare state.

bbartlog said at August 12, 2013 1:52 PM:

Someone thinks it hasn't been shown that humans have any biological desire to have children. I guess baby rabies is just a figment of our collective imagination...

James Bowery said at August 13, 2013 7:09 AM:

The argument over Randall's choice of words in the phrase "desire to have kids" is a pedantic red-herring -- especially when civilization is, arguably, selecting for people who are ever less-conscious of the consequences of their behavior. "Desire" may become obsolete as a descriptive when we are increasingly dealing with something more like peristalsis driving behavior.

David Friedman said at August 13, 2013 2:20 PM:

The evolutionary argument seems plausible, although it depends on the existence of phyloprogenitive genes. The ideal version, from the gene's standpoint, would be one that made people want to have children and thus undercut the various strategies by which humans substitute their objectives for the objectives of their genes. But one can imagine less extreme versions, such as a gene that made popular forms of contraception work less well.

But you seem to be taking for granted the claim that overpopulation is a serious problem. That was very widely accepted fifty years or so back, but the predictions made then have been pretty uniformly contradicted by experience. You might be interested in a very old piece of mine, "Laisssez-Faire in Population: The Least Bad Solution," webbed on my site, in which I tried to estimate the net externality from an additional child. My conclusion was that I could not sign it--there were positive and negative externalities, their size was uncertain, and the sum might well turn out to be positive. I have seen no reason since to alter that opinion.

Sometime in the sixties or early seventies I calculated population densities for countries and found that of the five most densely populated, none fit the then common stereotype of a country desperately poor from overpopulation. Two were rich European countries (Belgium and the Netherlands), three successful developing countries (South Korea, Taiwan, Singapore). Singapore had by a sizable margin the highest density. Hong Kong, which wasn't included because it wasn't a country, had about ten times the population density of Singapore--and since then, as you probably know, its per capita income has passed that of the U.K. The breakup of Pakistan created the first real world example of what popular opinion assumed to be the norm--a very poor country with a very dense population (Bangladesh).

David Friedman said at August 13, 2013 2:27 PM:

"The problem is, there is no reason to expect an overwhelming surge of prosperity among the 5.9 billion now living in developing countries. "

Except that it is happening. Chinese are getting rapidly more prosperous, Indians I think a little less rapidly. That adds up to about half of your 5.9 billion.

James Bowery said at August 13, 2013 2:59 PM:

From an anthropocentric point of view, the problem isn't population, it's selection. From this point of view it is not at all a settled matter whether civilization is a net win.

There are other points of view, the most prominent one being biocentrism. It is not controversial that from a biocentric point of view, civilization is a net loss -- but this presumes that civilization isn't expanding the ecological range of life, rather than remaining in the biosphere.

From a civilcentric point of view, civilization is good -- by definition.

Acksiom said at August 13, 2013 6:21 PM:

>It is not unreasonable to imagine the development of increasingly effective forms of birth control for men and women.


What did I post originally?

>>They're expecting FDA approval for market release in the usa by 2015.

>The question of course is how willingly would people use the methods.


What did I post originally?

>>a 99+% reversible MBC injection with a 10-year lifespan

It's non-hormonal, a purely material spermatocide, injected into the vas. It costs pennies. RISUG been in actual human evaluation for over a decade to test the longevity.

It's just about the jackpot in male birth control.

The Pill, for men, only better.

On schedule for market release in 2015.

And the only address it gets from people as obviously intelligent as you are, in a comment thread about population trends, is. . .

. .. to characterize it as imaginary, and question whether men and boys will use it.

Words fail me.

Randall Parker said at August 13, 2013 9:33 PM:

David Friedman,

Of course phyloprogenitive genes exist. We evolved. Natural selection has created many features in us that impact our likelihood of reproduction. Look at all the genetically controlled factors that influence desire to have kids or desire to engage in risky sexual behavior. Have you read A Farewell to Alms: A Brief Economic History of the World? We've lost those selective pressures and so now selective pressures have shifted heavily toward early puberty and other attributes that increase fertility.

Overpopulation worries in the 1970s: I'm reminded of the boy who cried wolf.

As far as bad things coming to pass: It depends on what you define as bad. I see lots of bad ecological trends. Depleting fisheries, dwindling rain forests, and the like.

Externalities of a child: it very much depends on the child. The predatory sorts of psychopaths have large externalities. People with MAOA knock-out mutation have lots of large externalities. Various others have differing levels of externalities. Genes for criminal behavior create some of the biggest externalities. Genes for lower IQ create externalities.

In the United States way more than half the population use more in tax-paid services than they pay for in taxes. That percentage is growing.

Vektor said at August 14, 2013 5:31 AM:

I agree with Acksiom in that RISUG (or whatever form the male pill takes) has the potential to be an enormous factor in natural selection, birth rates, and men's rights. Men will absolutely use it. How many 'planned' unplanned pregnancies will this prevent?

James Bowery said at August 14, 2013 9:23 AM:

RP writes: "Overpopulation worries in the 1970s: I'm reminded of the boy who cried wolf."

No, its pretty clear Ehrlich's genetic (perhaps entirely unconscious) agenda in Zero Population Growth was to encourage the demographic collapse of the Nation of Settlers. His movement had the most effect on that demography. Renaming "Zero Population Growth" to "The Population Connection" at the point in time when boomer female fertility was coming to an end and immigration was race-replacing the Nation of Settlers fits that model better than "the boy who cried wolf". I remember circa 1970 being in a Presbyterian Church in Des Moines at a meeting of ZPG where their priests were standing up in front of boomers entering fertility, occupying the exact niche of moral authority that used to support the fertility of those congregations. It was all so "moral" that I, myself, joined barely out of pubescence!

Ronald Brak said at August 15, 2013 5:42 PM:

Do human beings have a desire to have children that is influenced by genes which is separate from the desire to have sex? Probably not. While such genes would presumably be successful in an environment where people have autonomy and contraception is available, there is probably no combination of alleles that makes one specifically want to have children and which can be passed on genetically. While there might be strong selection pressure for such genes if they existed at the moment it doesn't mean that those genes exist. If I was to spend my days walking through the desert and shooting dead any tortoise I saw that didn't have a steel shell I might think I am providing selection pressure for steel shells in tortoises, but as there is no combination of alleles that can give a tortoise a steel shell I am really just providing selection pressure for tortoises that are hard to spot by gun toting loonies. Regardless of how sensible it might seem to have genes for some things, they simply may not be there. For example, do humans have genes for preserving food? Probably not. This sort of behavior appears to be determined by culture without a gentic component, despite its importance to survival in many areas. When it comes to genes and food storage dogs and bees seem to have us beat. This does not mean that genes can not influence food storage behavior, for example an person genetically disposed to be anxious might be more likely to store food or store more food, but we don't seem to have specific food storage genes. Another example is the treatment of injuries and illness. Genes for sensible medical care would be helpful for survival but actual medical treatment in different times and places has varies greatly in effectiveness and we've had to wait for the modern age for things such as basic hygiene to become widespread.

Just because we probably don't have a desire to have children that is directly influenced by genes doesn't mean that genes have no effect on our reproduction rates. For example, a woman in the developed world whose first child is pleasent and easy to care for is more likely to have a second child than a woman whose first child is a terror. Child temperament is affected by genetics and so we probably now have selection pressure for more pleasant children. However, it would be a mistake to think that our environment is not rapidly changing and that this selection pressure will remain constant. In fifty years time real children might be raised by robots while people who want to raise children themselves will go shopping for robot children since they come with off switches.

Acksiom said at August 17, 2013 11:52 AM:

>The only way I can see to prevent it: government-mandated genetic engineering of offspring to reduce the next generation's desire to have kids.

What about the coming RISUG/Vasalgel revolution in male birth control? They're expecting FDA approval for market release in the usa by 2015. I'm confident that a 99+% reversible MBC injection with a 10-year lifespan will be more than popular enough to throw off all their predictions. Did they mention that at all?

Red said at August 21, 2013 1:40 AM:

He's wrong. The drop in birth rates is mostly due to high female status. Every society that elevates the status of women ends up with a below reproduction levels of birth. The examples for this is: Sparta, Rome(after the republic), Babylon, Baghdad before the mongols.

Red said at August 21, 2013 1:45 AM:

Sparta in particular is a very good example of this. They were reduced to 12,000 fighting men despite huge cash intensives for spartan women to have children. After Sparta lost a war against Thebes and the helots revolted which deprived spartan women of managing the estates and slaves positions they had been occupying. The spartan state then returned to the Greek norm of highly low status wives and their population recovered quickly.

Red said at August 21, 2013 12:42 PM:

I was raised in a home schooling group of about 30 families. The only one I know of who had kids was girl who dropped out and become a meth head. 3 kids and counting. The rest of the girls are mostly married and not having children. I wouldn't count on home schooled families.

coolball said at August 24, 2013 11:44 AM:

"Genetic variants that alter fertility do not in any way counter the point I was making unless they alter fertility through some behavioural mechanism that is independent of sexual drive."

There are clearly biases in mate choice towards fertile mates and signs of fertility to the exclusion of infertile mates. This applies both to males and females, so there is clearly a selection for reproductive capacity irregardless of sexual capacity.

Tim Hogan said at August 26, 2013 7:13 AM:

Acksiom points out an easy to use male birth control will be ready in 2015. That's another reason the U.S. is destined to be mainly a Muslim nation by 2100. All is good with this "liberating" birth control for men except if your religion is Imam and doctrine focused on world domination through demographic inevitability. I can see the general utility if only for ensuring that Dearborn MI might be nearly as liberated as San Francisco by 2200. From my cultural focus and nearsighted perspective, male sexual liberation is not necessarily a good thing.

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