Wednesday, November 15, 2006

Darwin, Reproduction and Religion

I do not often link to other blogs, but I just came across a fascinating post in Future Pundit, arguing that Darwnian evolution will reverse both falling birth rates and declining religious belief—indeed is already reversing the latter.

The theoretical argument is simple and persuasive. Humans vary in, among other things, their taste for having children. It seems likely that some of that variation is genetic. We are now in an environment where reproductive success is limited mainly by parental choice, not by resource constraints; most people in developed societies could afford to rear many more children than they do. So people with more of a taste for having children, those who are more phyloprogenitive, will out-reproduce those who are less, increasing the share of their descendants in the population and, eventually, bringing average birth rates back up. While the author does not carry the argument all the way, the logical implication is that the process will continue until reproductive success is again constrained by resources—a Darwinian version of Malthus' old argument for why a society rich enough so that the cost of children was low could not be in long term equilibrium.

The second half of the argument, and the one the post centers on, is the relation between religion and fertility. FuturePundit quotes various authorites to the effect that, on a world wide basis, more religious people are also more fertile, not only across societies but within societies. By his account, while the decline in fertility has not yet reversed itself, the decline in religious belief has, due largely to the greater fertility of believers.

It is a persuasive argument, but I have one problem with it. Human generations are long, so human evolution is slow. I can well believe that if we maintained the world more or less as it is for five or ten generations, FuturePundit's predictions would come true; fertility rates would begin to rise and religious belief continue to become more common.

We are not going to maintain the world more or less as it is for that long. We live in a time of very rapid change, driven by technological progress. That makes all long term predictions highly uncertain—the main reason I am opposed to expensive precautions intended to prevent long term consequences of global warming.

Here is a short list of possible technological changes that might—or might not—reverse one element or another of the equation:

1. Artificial wombs, to convert the cost of childbearing from time and pain to money, thus giving a reproductive advantage to higher income couples and richer (and, on average, less religious) societies.

2. Uploading—the ability to reproduce oneself by copying the brain's software to a computer.

3. Advanced virtual reality or very good recreational drugs, providing the illusion of a heaven on earth to compete with religion's (I think illusory) promise of a future heaven, leaving the more active parts of life, including reproduction, to people with a strong preference for reality over fantasy.

Readers are invited to contribute more items for the list.

53 Comments:

At 6:50 PM, November 15, 2006, Blogger Rick and Gary said...

Religion-oriented people being more attracted to religion-based wars in which they kill one another.

 
At 7:18 PM, November 15, 2006, Blogger John Markley said...

Significant extension of the lifespan might increase fertility. As it is, taking (just for an example) a decade away from work to raise children would deprive a woman of a big percentage of the number of years she can work, which would be a pretty big obstacle for a woman who wants a career and wants to rise high in that career. The longer people live and are able to work, the smaller a sacrifice of one's total working life that ten (or however many) years will be as a percentage of the whole. Being able to climb the corporate ladder for only thirty years instead of forty before retirement is a big disadvantage; only being able to rise in the ranks for, say ninety years instead of a hundred is less of one. Extra decades of life would make it easier to "have it all," and thus women who don't want to be full-time homemakers would be less likely to forgo children for the sake of their careers; there would be less need to.

 
At 8:00 PM, November 15, 2006, Blogger Michael Anissimov said...

Wow, it's amazing to see you being so frankly transhumanist like this. Indeed, we must all embrace transhumanism - it is required for navigating around the risks and grasping the benefits of the future.

 
At 8:36 PM, November 15, 2006, Blogger Walter said...

"So people with more of a taste for having children, those who are more phyloprogenitive, will out-reproduce those who are less, increasing the share of their descendants in the population and, eventually, bringing average birth rates back up. While the author does not carry the argument all the way, the logical implication is that the process will continue until reproductive success is again constrained by resources..."

That's a pessimistic view of the economy in that future. It's plausible that future wealth will far outstrip the ability to reproduce. Perhaps a median income level will be sufficient to support a family with fifteen kids.

 
At 9:55 PM, November 15, 2006, Anonymous Arthur B. said...

One thing about religion. They do not all advocate high fertility... but the one that do not don't last long :P

Also the argument about poorer populations having more children has been put forward as being the proof that our society is dysgenic.

This is in my opinion wrong. Since human being collaborate and exchange, the mecanism for evolution has become quite different. It is enough of one person to discover something and make the whole world profit from it.

Thus, the fitness of a single individual affects the fitness of a whole population... in that system, from an evolutionnary algorithmic point of view, massive generation of random individuals maybe be more efficient than crossing.

The religions probably won't decline much because they are evolutionnary very stable. They generally command a moral code that is useful for staying out of trouble and are passed on to the next generation, with little alteration by refering to a strict standard.
Also the religious discourse has adapted to explain every new contradiction that comes in its way, retrieving to a final metaphysical corner.

 
At 10:01 PM, November 15, 2006, Blogger FuturePundit said...

Technological advances that make it easy for secular people to have more kids will also make it easier for religious people to have more kids.

Technological advances can be very disruptive. Robots might take over. Or we might live more of our mental lives in computer simulations with AI children.

But will simulated environments be equally attractive to atheists, agnostics, and people of various religions and sects? Instead might some groups decide that the simulated world is false and is the product of Satan trying to lead us all astray? Might others decide for other reasons that the simulated world is too unauthentic and choose to avoid it when possible?

If people react differently will any of the differences in reactions be due to genetic variations? If so, natural selection will have something to work on.

The development of Artificial Intelligence might instead have as its biggest effect the freeing up of people so that they have more time to reproduce.

People who consider reproduction more important could then have even more children. Those who do not have kids now might then become more likely to have kids. But the gap between them and those who now have many kids might not narrow.

Also, evolution is not slow if existing alleles make a big difference in response to a selective pressure.

 
At 6:43 AM, November 16, 2006, Anonymous albatross said...

The interesting question is what kind of humans will spread out from Earth to the solar system, and ultimately to the stars. That will be driven by ideas and beliefs about exploration and willingness to accept risk, I think. (Or maybe by the ability to survive an insanely selective process for choosing astronauts that is in practice only open to perfectly healthy test pilots, doctors, and scientists.)

 
At 7:30 AM, November 16, 2006, Blogger Pace said...

Brilliant. Of course David you are correct. Predictions about the future must account for dechnological developments rather than previous trends or natural processes like evolution. Essentially the human species has stopped the process of evolution by natural selection. From here artificial selection or engineering will determine the direction our species takes including branching into new species.

 
At 9:56 AM, November 16, 2006, Anonymous Christopher said...

Please accept my condolences on the death of your father, a great man to whom lovers of liberty owe a great debt.

 
At 10:07 AM, November 16, 2006, Blogger Rick said...

I'm very sorry to hear about your father, he will be missed.

 
At 10:24 AM, November 16, 2006, Blogger American Patriot said...

Your father's writings were a big influence on me. He will be sorely missed.

 
At 10:27 AM, November 16, 2006, Anonymous Anonymous said...

I'd also like to express my condolences to you and your family on the death of your father.

 
At 10:27 AM, November 16, 2006, Blogger Jonathan said...

Condolences and best wishes.

 
At 10:34 AM, November 16, 2006, Anonymous Daniel J. D'Amico said...

Condolences on the loss of your father.

 
At 10:48 AM, November 16, 2006, Anonymous David Emami said...

My condolences and sympathy on the passing of your father. I'll always have the greatest admiration for him.

 
At 11:04 AM, November 16, 2006, Anonymous Anonymous said...

My condolences to you and your family on your father's passing. We miss him already.

 
At 11:17 AM, November 16, 2006, Blogger montestruc said...

walter said:
----quote
"So people with more of a taste for having children, those who are more phyloprogenitive, will out-reproduce those who are less, increasing the share of their descendants in the population and, eventually, bringing average birth rates back up. While the author does not carry the argument all the way, the logical implication is that the process will continue until reproductive success is again constrained by resources..."

That's a pessimistic view of the economy in that future. It's plausible that future wealth will far outstrip the ability to reproduce. Perhaps a median income level will be sufficient to support a family with fifteen kids.
---------end quote

Suggest you spend some time in study of growth curves, especially exponetial ones.

Friedman is right, given the arguement that human desire to reproduce has a large genetic vector, (which it must) we are now obviously breeding in favor of those who prefer to have large numbers of offspring, as this trend continues and if nothging else inturrupts it, the logical consiquence is that we hit the resource limits, and possibly crash.

 
At 11:19 AM, November 16, 2006, Blogger montestruc said...

My condolences as well, he was a great man.

 
At 11:34 AM, November 16, 2006, Blogger John Markley said...

Please accept my condolences also. I admired your father greatly.

 
At 11:39 AM, November 16, 2006, Anonymous Anonymous said...

My condolences. May his memory be a blessing.

 
At 11:43 AM, November 16, 2006, Blogger Malcolm Kirkpatrick said...

David,

I took exactly this position in the sci.econ newsgroup, post #38 (panther = Malcolm Kirkpatrick, 13-Oct-1999. Don't I get any credit, too?

Your father was a great man. I am sorry for your loss, and ours.

 
At 11:46 AM, November 16, 2006, Blogger Richard said...

My sympathies for you and your family at the loss of your father. Capitalism and Freedom was one of the first libertarian books that I read, when I first found that is where my politics lie, and it was one I have recently picked up again. Your father was a great man.

 
At 12:14 PM, November 16, 2006, Blogger Malcolm Kirkpatrick said...

Sci.econ. 1999-Oct. "Cato Institute News Memo: Global population increase a positive trend".

Earlier in thread:
(Malcolm Kirkpatrick): "Voluntary programs for population selectively breed non-compliant individuals"...

(David Friedman): "If we are really programmed in that way, why is it that the U.S., and most
developed countries, have birth rates near, in some cases below,
replacement?

(Malcolm Kirkpatrick): "Pausing for breath. It won't last. All life on Earth is related.
Birds are your cousins. Try talking pigeons out of reproducing."

 
At 12:15 PM, November 16, 2006, Blogger Malcolm Kirkpatrick said...

Should be "population control".

 
At 12:18 PM, November 16, 2006, Blogger Vache Folle said...

While it is plausible that people vary in the degree or intensity with which they desire offspring, I am inclined to believe that it is the cost factor which accounts for lower total fertility rates in developed countries and within more educated and affluent segments of populations. If we assume that everyone weighs the entertainment value of children (their economic value is negligible in America), i.e. the "benefits" more or less the same, differences in "cost" adequately explain variable fertility. I regard women's opportunity costs as one of the most significant factors and highly explanatory. Educated women, who tend not to be religious fundamentalists, bear enormous opportunity costs compared to their lower earning counterparts.

This goes a good way toward explaining lower fertility's correlation with greater education and less religiosity.

 
At 12:41 PM, November 16, 2006, Blogger michael said...

My condolences to you and your family. Your father was, and forever shall be, a great man.

 
At 12:41 PM, November 16, 2006, Anonymous albatross said...

I was also sorry to hear of your father's passing away. He had a huge impact on the world, overwhelmingly for the better. Among other things, I believe he had a big impact on the fact that we got rid of the draftee army. If that's not freeing the slaves exactly, it's not all that far from it.

 
At 12:42 PM, November 16, 2006, Blogger Malcolm Kirkpatrick said...

Vache folle,

I'm surprised that a Dawkins fan would assume that "everyone weighs the entertainment value of children", at least any more than pigeons weigh the entertainment value of children.

Parents roll a giant bucket of dice when they put their kids together. Conception is a crapshoot and some kids come up snake-eyes. The human and canine IQ curves overlap.

In a society which simultaneously subsidizes childbearing (welfare, "free" "public education") and imposes large costs on child-raising (legal liability, private school tuition or a mortgage in a neighborhood with decent schools), the income:fertility (x,y) plot will be U-shaped. Over evolutionary time, voluntary programs for population control must selectively breed non-compliant individuals.

Guess I needed an academic credential when I said this the first time.

 
At 12:54 PM, November 16, 2006, Anonymous Arthur B. said...

All my condolences, death is always a tragedy.

 
At 12:59 PM, November 16, 2006, Anonymous Patrick said...

David -

I'm very sorry to hear of the loss of your father. Our sympathies are with you and your family.

 
At 1:01 PM, November 16, 2006, Blogger M.C. said...

My deepest condolences to you.

 
At 1:31 PM, November 16, 2006, Anonymous Anonymous said...

David,

Very sorry to hear about your loss. He was a great man, who will never be forgotten. You have all of our condolences.

 
At 1:37 PM, November 16, 2006, Anonymous William Crain said...

My condolences as well. A great loss for us all.

 
At 1:45 PM, November 16, 2006, Anonymous adam said...

My condolences on the death of your father.

 
At 1:51 PM, November 16, 2006, Blogger R.S. Porter said...

Condolences to you and your family on this day of great loss. Your father will be remembered as a great man who did much for the cause of freedom.

 
At 1:53 PM, November 16, 2006, Anonymous Jakob said...

My deepest condolences.

From Denmark

 
At 1:56 PM, November 16, 2006, Anonymous Peter said...

My condolences from Aalborg.
Truly, he was a great man.
May he rest in peace.

 
At 2:17 PM, November 16, 2006, Anonymous Ben Litchman said...

My condolences to you and your family. Your father is one of my heroes, and one of the reasons why I'm pursuing a degree in economics right now.

 
At 2:38 PM, November 16, 2006, Anonymous Stevo Darkly said...

My condolences also, on the passing of your father.

He was a great man, and a producer of great ideas.

Come to think of it, he was also the producer of a man who produces great ideas. (_Machinery of Freedom_ had a lot to do with making me a libertarian and, ultimately, an anarcho-capitalist.)

 
At 3:02 PM, November 16, 2006, Blogger Peripatético said...

Accept my condelences on your loss. The friends of libery and freedom are in mourning worldwide. A great man adn master indeed!

Sincerelly from Brazil

 
At 4:16 PM, November 16, 2006, Anonymous RKN said...

Friedman is right, given the arguement that human desire to reproduce has a large genetic vector, (which it must) we are now obviously breeding in favor of those who prefer to have large numbers of offspring

Must? It's not obvious to me that the preference for many children must have a large “genetic vector.” I would need to see a credible scientific cite for this claim.

Environmental circumstances and influences have a great deal to do with shaping indivudual preferences. The preference for children – none, one, two, or many – is no different.

In any case it shouldn’t be a difficult hypothesis to test. Survey a generation of parents and count their children and siblings. Continually step back one generation at a time and do the same. Cross plot the data. Make a separate plot for identical twins. Perform the appropriate statistical controls. Calculate the correlation coefficient(s).

Does a strong correlation exist? If it does not, then we can’t reject the hypothesis that environment more strongly predicts fecundity. If a strong correlation does exist (particularly with the twin data), then maybe your must has some merit, else it’s scientifically baseless.

One other comment:

FuturePundit said: “Surely instinctive desires for children exist in our DNA and they'll be discovered within the next couple of decades as DNA testing technologies become cheap and easy.”

The statement is nonsense. Improved DNA testing technologies have nothing to do with improving our ability to “discover instincts in our genes.” Mapping of a phenotype to genotype, specifically psychological phenotypes like preferences, is nothing more than hand-waving at this point. What we know for sure is that environmental cues have a GREAT deal to do with determining psychological phenotype. Genes in this case merely represent potential; they are by no means strictly deterministic.

There’s far too much of this kind of nonsense coming from people who don’t understand what they’re talking about.

-----------
Friedmans: Peace to you all, and your familes.

 
At 5:12 PM, November 16, 2006, Blogger Malcolm Kirkpatrick said...

David changed of sides on this issue, from the time we argued the relation between clutch size in this generation and clutch size in the next, on usenet in 1999, and now. Glad to have him on board.

Some animals adjust litter size or clutch size (number of eggs) in response to changes in available resources. Plants also adjust to rainfall and nutrient availability, within the lifespan of individuals. Ordinary evolutionary considerations suggest that genetic programming will adjust over generations.

 
At 6:58 PM, November 16, 2006, Blogger David Friedman said...

Vache argues that cost of children explains much of the variation with income, education, etc.

It's a little tricky. Vache seems to use "everyone weighs the entertainment value of children ... more or less the same" to mean "everyone has the same dollar value for ... ." But surely a more plausible first approximation is that everyone has the same utility value for the entertainment value of children. If so, dollar value will be higher for higher income parents, to balance the higher cost, so it isn't clear what the net effect will be.

 
At 4:54 PM, November 17, 2006, Blogger deaner said...

Don't you have to first establish that religious belief is passed from generation to generation? If overall "religiousity" is declining, it suggests that the transmission is less than 100% - and casual observation leads me to think that it is significantly less; but I am not familiar with highly religious subgroups, much less with a statistically significant sample.

 
At 12:44 PM, November 19, 2006, Anonymous Mark said...

I would guess that the reason that religious people have more children than secular people is that their communities encourage it, with the underlying assumption being that the group benefits when its members have more children. I doubt it has much to do with their scriptures. If secularists were to form tight-knit groups similar to churches (possibly with the goal of defending their lifestyles and rights from religious people) maybe they would create their own support systems that encouraged having more children.

 
At 10:07 AM, November 24, 2006, Blogger Rick and Gary said...

Walter says, "It's plausible that future wealth will far outstrip the ability to reproduce. Perhaps a median income level will be sufficient to support a family with fifteen kids."

That's not the trend that we have seen so far. Wealth has doubled and the cost of raising kids is more onerous than ever.

My guess is that the cost of kids increases faster than wealth since kids are used to absorb discretionary income.

 
At 11:25 AM, November 26, 2006, Blogger FuturePundit said...

How much money you spend on kids depends in large part on how much money you have to spend on them.

Poorer people may be more inclined to have kids in part because they can't afford other forms of entertainment. Though I hesitate to use the term "entertainment" to describe the sorts of desires they are trying to fulfill.

Going back to David Friedman's original comments: Just because someone might some day be able to upload a copy of their consciousness into a computer will not necessarily make the original version of that person less likely to have kids.

If the original version connects to the web with all nerves and ceases to experience the physical world where the body sits in some vat then the desire for physical reproduction might get replaced with the desire for AI children. Then again, maybe not.

 
At 11:29 AM, November 26, 2006, Blogger FuturePundit said...

rkn,

Committed believers in the environmetalist Blank Slate faith put a higher bar for proof of genetic causes of human behavior than on environmental causes. This faith is headed for a fall. Cheap DNA testing really will make it far easer to map from genetic variations to phenotypes. Massive population comparisons of genetic variations and assorted attributes will turn up lots of genetic variations that contribute to behavior.

Genotypes really do map to phenotypes. Also, humans really do have instincts. Calling that nonsense will not change that our minds are products of evolution and still under heavy selective pressure.

 
At 11:16 AM, November 27, 2006, Anonymous RKN said...

futurepundit,

Genotypes really do map to phenotypes.

Some do. But can you name a single psychological phenotype that maps to a gene loci? Or are you just hand waving?

Also, humans really do have instincts. Calling that nonsense [...]

I didn't say instincts or genotype-phenotype mapping were nonsense. I said it was nonsense to claim, as you did, that "cheap 'n easy" DNA tests would enable the discovery of instincts. DNA testing is already easy. Building sequence databases is a breeze. The challenge is one of bioinformatics, not testing technologies.

Your understanding of the relevant science is out of date if you mock, as you seem to, the important role environmental circumstances and cues play in shaping an organism's behavior. The field of epigenetics, to name only one example, is a very active area of research right now. There are any number of non-genetic factors that regulate gene EXPRESSION.

Btw, I think it's arguable that "minds", as you say, are presently under selective pressure. Look around; at least in this country there appears to be an inverse relationship between wisdom and fecundity.

 
At 9:45 PM, December 15, 2006, Anonymous Anonymous said...

Darwin, religion and reproduction. I have often considered the notion that religion itself could be an evolutionary belief that that has become so routine over countless generations, it has literally embedded itself in out genes, much the way a bird is able to build a nest without ever witnessing the process.

 
At 5:57 PM, December 23, 2006, Anonymous Anonymous said...

The two funniest lines in this otherwise dismal thread are:

"Indeed, we must all embrace transhumanism - it is required for navigating around the risks and grasping the benefits of the future."

"Technological advances can be very disruptive. Robots might take over."

 
At 1:36 PM, December 31, 2006, Blogger Matt said...

Hey guys, religious belief is not under natural selection- either positive or negative.. There is not a heritable component, which is necessary for selection to operate.
http://matt-at-berkeley.blogspot.com

 
At 10:29 AM, May 26, 2013, Anonymous Anonymous said...

Darwin theorizes that certain traits will give species an advantage in survival. One trait for humans is that towards spirituality, which I believe we all posses but for many it goes untapped. It is said that religious people are typically happier and more optimistic than the rest of the population so I can see where this argument leads to say that those who have the evolutionary advantage of religious belief will populate the earth much more steadily.

 

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