February 24, 2009
Theistically Confident Make More Babies

Natural selection in the human race has not stopped. Blogger Audacious Epigone uncovers an interesting pattern in General Social Survey data. Those with firm belief in God and those with firm belief God doesn't exist make more babies. My take: the genes for doubt and skepticism are getting selected against.

The great back-and-forth between Jason Malloy and Bruce G. Charlton led me to wonder if the trend of increased fertility as theistic confidence increases conscious, or if it a subconscious and indirect consequence of values and behaviors not explicitly related to a person's stated ideal family size. BGC suggested that secular women do not just have fewer children than the religious do, but that this stems from a desire to have fewer children to begin with.

From GSS data, I looked at the reported ideal family size* and the actual number of children had, by theistic confidence, among those who had essentially completed their total fertility (age 40-100):

Theistic confidenceDesiredActual
Don't believe2.262.23
No way to find out2.251.95
Some higher power2.181.98
Believe sometimes2.372.34
Believe with doubts2.342.31
Know God exists2.582.64

The more theistic, the greater the number of ideal children for a completed family to contain. It tracks almost identically with the actual number of children given birth to. That's not too surprising, since people are probably biased towards defining their actual family size as the ideal family size.

Granted, those who believe in God surpass the atheists in fertility. But the biggest doubters have the lowest fertility levels. Either the feeling of certainty boosts fertility or some factor causes both certainty and higher fertility.

As long time readers know one of my interests in the future has to do with which way will human evolution go? The DNA sequencing evidence already points int the direction that human evolution has already accelerated by orders of magnitude in the last 10,000 years and we aren't the same humans as those who walked the Earth even a few thousand years ago. An excellent recent book, The 10,000 Year Explosion: How Civilization Accelerated Human Evolution, explores these findings in greater detail.

But what of the future? My fear is that the human race will splinter into subspecies that have cognitive dissimilarities that lead to wars of enormous lethality on a scale beyond any wars to date. Will genetic engineering for higher IQ give us the insights to doubt our own feelings of certainty and do a better job of seeing the viewpoints of others? Or will some faction of future transhumans use their greater intellectual abilities to ruthlessly pursue the triumph of their genetically engineered extremely strongly felt moral preferences?

Share |      Randall Parker, 2009 February 24 09:08 PM  Trends, Human Evolution

Thras said at February 24, 2009 9:23 PM:

Maybe it is doubt and skepticism being selected against. Maybe something else. The people in between are also the people who haven't thought deeply about the matter. (Fundamental religiosity.) They are the people who are more worried about expressing firm views. (Social conformism.)

Of course, as far as I can tell, actual skepticism seems to have no correlation with what part of the religious spectrum a person falls in. People choose religion, atheism, agnosticism, all for wonderfully stupid reasons.

Carl Pham said at February 24, 2009 9:37 PM:

Goodness, I hate to break it to you, but the jury is still out on whether intelligence is of any serious long-term survival value. Generally, the consensus from nature seems to be that it's not, that it's just too unreliable and slow. The better approach is to wire hard beliefs into the DNA, on which the individual acts with maximum energy and speed, and then make sure the species has a liberal distribution of such beliefs, such that at least some viable subpopulation possesses the most adaptive set of beliefs at any given moment in the ongoing fluctuations of the environment.

I realize you enjoy your conscious intelligence, and think it the most wonderful thing in the world. But...um...you're simply wired to feel that way, and are that part of the species set aside in case Captain Kirk ever descends and phasers to death everyone who can't pass the Federation citizenship test.

Finnsense said at February 25, 2009 12:57 AM:

That's an interesting study but I don't think there is much reason to worry. Evolution will cease to be a natural process in 70 years. Anyone with access will just have smarter babies (as well as bigger, healthier and more beautiful ones) and there is a very clear correlation between intelligence and belief in God. Theism is also going to be much harder to maintain as science and technology progress.

Dave Gore said at February 25, 2009 8:39 AM:

In 70 years mankind may have the ability to engineer better children, but who will do the hard work of raising those children? Mormons not only have a lot of children; they have a culture that is supportive of large families. Those who choose to rear children will determine what the children's genetic and cultural heritage will be. The opinions of those who dislike children will be ignored. However you slice it, the future belongs to those who replace themselves.

Realist said at February 25, 2009 12:47 PM:

I believe you've misinterpreted the data. As Alex Birch on Corrupt.org explains:

"I think the real answer is much more simple: People who believe in God are more likely to be a part of a religious movement, like Christianity or Catholicism, and these people in turn tend to have more conservative family values. Atheists tend to have more liberal values and thus place more focus on career and self-fulfillment than bringing up lots of children in a family."

I agree thought that this is a problem.

Xenophon Hendrix said at February 25, 2009 12:52 PM:

Whenever I try to seriously think about the future, I soon find myself staring up at the looming presence of the Singularity. Note that there are multiple potential ways for intelligent beings smarter than humans to come about, not just computers getting smart. In any event, once they get here, their actions will presumably be beyond our abilities to predict.

Nevertheless, taking wild guesses about the future is a temptation that long-time science fiction readers can't resist.

I think we will see new intelligent species come about simply because some people will want them to. Think about sapient beings designed to better face the rigors of living in space or the ocean. Maybe we'll see hybrids of electronics and neurons designed to be born filters of the vast webs of data that we are sure to keep accumulating. No doubt, if not suppressed by strong governments, some new species will be created for ideological reasons, perhaps intelligent vegetarians or functional hermaphrodites.

Will new species necessarily go to war? Wars are usually fought over limited resources. It looks like nanotechnology and biotechnology should be able to continue the recent trend in accelerated resource creation. If that is the case, large-scale wars might be put off for quite some time, at least until the resource acceleration stops. I wouldn't be too hopeful about ending police-action-type wars, though. But perhaps in the future they will take the form of narrowly targeted assassinations.

Furthermore, I think it's possible that new species might be designed with symbiosis in mind. One wouldn't want to go to war with one's symbionts, and I'm guessing that future species designers will be smarter and have more foresight than anyone living today.

On the other hand, I'm a lot less optimistic than Robert A. Heinlein and other Golden Age science-fiction authors were about the chance of wild-type humans spreading out into the solar system and then the galaxy beyond. I don't think we are going to have the time. It looks to me that by the time space colonization becomes practical, we will already be taking our evolution in hand.

It might start with just choosing the best egg out of ten, but it will soon go on to replacing actual genes. We might even start creating offspring who are natural cyborgs. Imagine a person who is smarter and more creative than a Gauss but who has grown up with a networked computer interfaced directly with his brain. That's just a timid possibility caused by my lack of imagination.

When superior beings like that take their natural places of leadership, will they allow wild humans to keep running riot? I'm inclined to doubt it. If wild humans can't be retrofitted, their best chance is going to be as pets. Maybe our owners will be kind and give us each our own virtual fantasy world to live in.

At least that's how I think in my less optimistic moods. I hope I'm wrong about our fate.

On the gripping hand is the darkest thought of all. Fermi's question: "Where is everybody?" It could be that no species ever gets much beyond where we currently are.

Geoff said at February 25, 2009 5:56 PM:

Maybe one day they'll find the gene which causes people to believe all belief tendencies are caused by genes.

seerak said at February 25, 2009 5:58 PM:

It could be that no species ever gets much beyond where we currently are.

So long as ideas like "genes for doubt and skepticism" are still around, we may not survive.

For conceptual beings like mankind, the dominant force that determines survivability is no longer genetics, but *ideas*. Bad ideas kill; good ones result in gigantic population booms and varying degrees of emancipation from natural constraints such as predators, disease and natural disasters.

As evidence, note that the biggest killer of humans in the last century was bad ideas; collectivism in its in various forms (communism, socialism and fascism) murdered millions -- while the ideas that led to human prosperity came from the Enlightenment liberal tradition: freedom, capitalism.

The survival of mankind, and very likely of all sentient species, isn't about evolution anymore; it's now about the ideas in our heads. There are no genes for that; only choices. If we blow ourselves up, it won't be genetic; it will just people acting on bad ideas.

Assistant Village Idiot said at February 25, 2009 6:20 PM:

Finnsense, I am not aware of your data for "a very clear correlation between intelligence and belief in God." From your subsequent comment, you seem to believe it is a negative correlation. Either way, I don't know what data you are referring to.

New Frontiersman said at February 25, 2009 7:07 PM:

Realist --

Look at the numbers again, in the Actual column. Real atheists have more kids (2.23) than the agnostic (1.95) and the ones who vaguely believe in the existence of a higher power (1.98). It's pretty obvious that atheists are not more likely to be a part of a religious movement than agnostics and vague believers in a higher power; indeed, quite the opposite.

Certainly, divided into two subgroups, the non-theists and theists, the theists outreproduce the non-theists. But within each subgroup, the stronger adherence to the opinion, the more kids. Just as the definite theists out-reproduce the unsure theists, the definite atheists out-reproduce other non-theists. Assuming the numbers used have statistical significance, strong resolution either way seems to have an positive correlation with fertility independent of the expected influence of pro-fertility religious teachings.

J said at February 25, 2009 8:21 PM:

"Will genetic engineering for higher IQ give us the insights to doubt our own feelings of certainty and do a better job of seeing the viewpoints of others? Or will some faction of future transhumans use their greater intellectual abilities to ruthlessly pursue the triumph of their genetically engineered extremely strongly felt moral preferences?"

Your optimism that these things would conflict with each other is encouraging, but I suspect the answer to the second question is almost certainly yes, regardless of the answer to the first. From Marginal Revolution a few weeks ago:

"In 7 different studies, the authors observed that a large number of thinking biases are uncorrelated with cognitive ability."


skydaddy said at February 25, 2009 9:33 PM:

It's wonderfully ironic how the ad-placement-relevance engine put an ad for dummies.com in this thread.

"The fool has said in his heart, 'There is no God,'" - Psalm 14:1

Telford Work said at February 25, 2009 10:14 PM:

Who says belief in God (or even predisposition to belief in God) is genetic? If it's cultural/traditional/ideological, then the 'meme' propagates by other means than biology. All you need is for the skeptics to control the educational system (or the believers or atheists, whichever) and they could gain an advantage over family -- which is only temporary if it's not genetically hard-wired.

Tom said at February 26, 2009 2:38 AM:

This is simple : "evolutionists" are not honest people. To them, evolution is a word, devoid of any meaning or content, an excuse not to go to church on sunday. An excuse to look at porn sites. An excuse to steal/act like jealous morons/"free" sex/... They will scream their lungs out once terms like "survival of the fittest", "law of the jungle", or "why would anyone who believes the primary function of a human is to spread his/her genes use a condom ?" start leaking in the conversation.

Pointing out the differences in rational behavior given evolution versus rational behavior given Jesus is a huge no-no. Even though this is a simple economic problem. An obvious differences between Christian ethics and evolutionist ethics would be that an evolutionist, who acts rationally to maximize the spread of his own genes, will attempt to kill any child of any woman he has slept with that does not carry his genes. Pointing out that this is a long known fact (and that many animals exhibit such behavior, e.g. lions, monkeys, ..., which confirms that this behavior has a positive effect on the spread of one's genes).

You see "evolution" supporters are no fans, at all, of natural selection. They claim that natural selection doesn't have to involve violence, a fact which is superficially correct. However whatever actions one takes to "optimize" natural selection to one's own advantage ends in the death of others (because that's the point of those actions to begin with). They are non-violent only when there are non-violent ways to kill. Obviously violence brings risk for both the attacker and victim, so peaceful solution is preferable. But someone acting on "spreading one's genes" impulses WILL use violence if he cannot kill others "peacefully".

If these people are equally honest to their partners in life, perhaps it's best they don't have children.

The sad thing is, the more discussions I watch creationists versus evolutionists, the more I'm picking sides for the creationists. At least they're consistent, and don't lie about scientific results. Yes you heard me right. They plainly state they don't accept those results as true, whereas most creationists sometimes make up scientific results out of thin air to support their point, and deny other scientific results (like the killing stephchildren issue for example, or they try to wiggle their way out of the condom issue, or the gay issue (attacking gays is another behavior that's beyond widespread in the animal kingdom, and the species that don't do so are the exceptions to the rule, not the rule).

Brandyjane said at February 26, 2009 4:06 AM:

When I consider all of the brilliant theists throughout human history, I cannot understand how anyone could seriously imply that people who believe in God are inherently less intelligent than atheists and doubters. Would anyone honestly propose that Sir Isaac Newton or most other members of the Royal Society were unintelligent? What about the majority of America's Founding Fathers? (Note - I am not saying all of these people were orthodox Christians. Newton had some pretty heretical views on the nature of Christ's divinity, and many of the Founding Fathers were deists. My point is that they believed in God.) Some would argue that, yes, they were brilliant, but they were wrong about the existence of God, and today we just "know better." That's garbage. Since the time of the earliest Greek philosophers, there have been those who sought to prove through philosophy or science that there is no God, yet throughout history, the majority of humans - even the majority of extremely bright humans - have believed in some sort of god. I am not arguing that atheists are unintelligent. I know many very smart atheists and agnostics. So why do so many atheists find it necessary to jump to the argument that people who believe in God are just stupid? It's not logical, it's not consistent with historical observation, and it practically screams insecurity about one's own (lack of) belief. Can't believers and non-believer's ever have an honest debate without one side resorting to childish "you're stupid" name-calling?

Woody said at February 26, 2009 4:50 AM:

In order for this concept to work religious beliefs would have to be passed from the parents to the children, and I can tell you from personal experience that is often not the case. If just half the children of a religious couple can grow up to become atheists because their exposure to science, archaeology and history leads them to doubt, then that at least evens out the theists advantage. If mankind's knowledge conitnues to grow at this pace this would likely accelerate don't you think? I'm guessing the theists will have a hard time keeping up with this.

Mitch H. said at February 26, 2009 6:05 AM:

The nonintuitive result from that survey is that atheists have a higher-than-average family size, which is completely against every previous bit of data I've noticed and contradictory to my own anecdotal experience. There's some suggestion that the atheist sample is abnormally small, and biased by a couple of accidental outliers (two atheists with six-kid families in a sample of forty-some atheists all told). If it's *true*, then I've been basing a lot of my understanding of the future on incorrect demographic assumptions.

I don't think it's a valid result, I'm just saying that if it is, then the apparent evidence of the Warsaw Pact & secular Western European populations' demographic collapse has been contaminated by accidental correlations with orthogonal factors - cultural morale failures, most likely.

Rosey said at February 26, 2009 6:47 AM:

While reproductive rates of these cohorts, examined in isolation, project the author's conclusion, they are easily outweighed by other factors. For instance, Jarod Diamonds' "Guns, Germs, and Steel" analysis suggests that survivability is better predicted by the relative lethality of one neighbor tribe over the other. The source of that lethality comes from warfare, immunology, or commercial technology. He does not spend a lot of time on the glue that holds tribes together, such as religious affiliations, but I suspect it is a factor in survivability. Consider the resilience of the Taliban, barbaric as they are.

If we hypothesize that long term, multi-generational tribal survivability -- tribal resilience, is evidence of superior genes, the candidate tribes are a very short list indeed. If we include only the technological accomplished, we are left with only one tribe -- the Orthodox Jews. Their tribal narrative dates back, by their reckoning, almost 6,000 years. They have reproductive rates of, typically, 8 to 12 children per couple. The glue that holds them together is profoundly monotheistic. They value learning, fight only defensive wars, and consider procreation a foundational purpose for existence.

In real numbers, to project Diamond's thesis, the earth will be Muslim in about a half-dozen generations unless their lethality is stopped, as they are breeding like rabbits, with their ethic that females are mere breeding stock.

samson said at February 26, 2009 7:07 AM:

here's your argument, Randall, as I see it:
1) suppose there is a genetic basis for doubt and skepticism. this does not mean that there might be a need for a particular set of environments to have gene expression.
2) suppose people who are more doubtful/skeptical/agnostic/fence-sitters procreate less rapidly than the confident/swaggering/self-righteous
3) the logic of evolutionary theory is that differential replication rates of genes in a population in the long-run lead to the rapid-replicator becoming a larger and larger fraction of the population
4) if the death rates are not affected by having one or the other trait, then we have the conclusion that being doubtful and skeptical is selected against.

I think you need to make a better case for statement 1), but I wouldn't be too surprised if it were true. My prior belief is that it is at least partly true.
Your post presents evidence for part 2) but not the whole picture -- see my criticism below.
Statement 3) is the central insight of evolutionary theory.
Statement 4) points out that matters aren't so simple as higher birth rates implies selection for gene. There are numerous interactions that can occur between a gene and other genetic and behavioral traits that can reduce the fitness of the gene. One example is if the kids of the cocky are for some reason more likely to die before reproducing then the selection advantage is no longer necessary. perhaps confidence is closely related to risk-taking behavior, which most likely increases the chance of dying before passing on the genes. I think evidence that there is no differential in reproduction rates of offspring is important.

As always, thanks for the interesting posts.

inchdeep said at February 26, 2009 7:20 AM:

Again in a Universe that was just an accident, sucking all objective meaning for your life, who cares. Your concerns irrelevant.

Mike Devx said at February 26, 2009 7:40 AM:

The statistics are real and true. Remember, these statistics are about *trends*. The doubters and and dissemblers *tend* to focus on the short-term and the here and now. "What's in it for me?" is their question, because they see the universe as completely purposeless and devoid of any meaning. It's interesting that committed atheists form a strong-enough world view to take the criticism and avow their atheism publicly - and that appears to be a strong enough belief system to take a long-term view. Committed theists, of any religion, of course take the long-term view.

And the long-term view is the key for the *trend* of having more children. More committed theists - even atheists - tend to have more children. The doubters and the secularists, who are not committed to any theology nor atheism, but simply live day to day, focused only the short-term, tend to have fewer children.

The trend is far stronger in Europe than here. And you don't even want to ask about Caucasion Russia, which is facing a demographic meltdown with their 1.60 or lower ratio. Even our worst doubters are close to a 2.00 child ratio per 2.00 adults. (Of course, replacement is actually about 2.20, I think, so even a 2.00-group would face very slowly declining demographics and eventual extinction.

OneEyedMan said at February 26, 2009 10:08 AM:

Could be the reverse causality. I don't know how the GSS is conducted, but if belief is measured after child rearing is complete, it could very well be that having a larger number of children causes the extremes of beliefs.

Randall Parker said at February 28, 2009 3:47 PM:


Death rates at young ages are so low in industrialized countries that I tend to discount death as a selective pressure as compared to fertility rates.

As for a genetic basis for doubt and skepticism: I sometimes write posts about genetic causes of personality traits. But mostly my attitude is this: Why would we have personality traits in the first place unless they had some selective value?

Post a comment
Name (not anon or anonymous):
Email Address:
Remember info?

Go Read More Posts On FuturePundit
Site Traffic Info
The contents of this site are copyright