Religion isn't the only thing becoming extinct in those nations.
Go to Wikipedia and search for "Demographics of X" where X is a nation from the list given in the above-linked article: Australia, Austria, Canada, Czech Republic, Finland, Ireland, the Netherlands, New Zealand, and Switzerland.
Those numbers are for the years 2007 to 2009, depending on the nation. Note that only Ireland and New Zealand are at replacement levels. Residual Catholic natalism may explain Ireland's current fertility (given their loss of religion, don't expect that to last). Reading between the lines in the Wikipedia article for New Zealand, it seems that the Maori and Pacific Islanders are doing more than their fair share of baby-making. My guess is that they are more religious than the contracepting whites.
Bottom line: Lack of religion is either non-adaptive from a fitness perspective, or it is strongly tied to traits which are themselves non-adaptive.
UPDATE: I can't get the formatting right on that table of fertility rates.
The number for Iceland is the only one that surprises me. The rest exemplify the general trend in the West in modern times: religion has been on the wane and irreligious people are not as interested in baby-making as religious believers.
Let's not get fooled by reputations. We may think of Spain, Portugal, and Italy as being very religious countries, but the Catholic Church more or less gave up trying to do its job starting with Vatican II. Turkey has had a secular (and secularizing) government since Ataturk. Hungary, Estonia, and other Eastern European nations were under Marxist indoctrination for more than forty years. In the Balkans (e.g., Greece), religion is more a marker for ethnicity than a guide for living life.
Much of the positive side of the ledger for population in Western nations is due to immigration of people who are induced to have children either as an act of piety (Muslims in Europe) or as a matter of custom (Mexicans in the United States). The above chart does not contradict this.
In the countries with declining reproduction, I'd be interested to see how rate of procreation relates to income-level. Is it the well off who are not reproducing, or the relatively poor?
Closest thing you can do is put two spaces in front of every line and monospace it:
Nation Total Fertility Rate
------------------------------------
Australia 1.97
Austria 1.41
Canada 1.58
Czech Republic 1.49
Finland 1.85
Ireland 2.1
Netherlands 1.66
New Zealand 2.1
Switzerland 1.46
(Also, I'm just doing the convenience of formatting it in this message. No particular endorsement or independent verification here.)
What do you make of France, which with Ireland has the highest fertility rate in Europe (2.01 in 2010 [1]), while Catholicism can hardly be described as thriving there: 4.5% of French people go to mass at least once a week [2].
Social policies such as benefits for families with two or more kids and low-cost, widely available day-care centers for children under 3 that allow women to work and have kids sound far more important to me than any "residual Catholic natalism".
The laws of France make it notoriously difficult to gather data on the correlation between religion and fertility, but the best available studies show that in France "[t]he estimated fertility of a woman assisting [religious] offices every week is 24% higher that the expected fertility of a woman who never assist to offices."
There used to be a saying among French Catholics: "If the traditionalists win, then the liturgical language of France will be Latin. If they lose, it will be Arabic."
Muslim immigration into France accounts for the high fertility.
he birthrates of Muslim women in Europe have been falling significantly for some time. In the Netherlands, for example, the TFR among Dutch-born women rose between 1990 and 2005 from 1.6 to 1.7. In the same period for Moroccan-born women in Holland it fell from 4.9 to 2.9, and for Turkish-born women in Holland from 3.2 to 1.9.
In Austria, the TFR of Muslim women fell from 3.1 to 2.3 from 1981 to 2001. In 1970 Turkish-born women in Germany had on average two children more than German-born women. By 1996 the difference had fallen to one child and has now dropped to 0.5. These sharp falls reflect important cultural shifts, which include the impact of universal female education, rising living standards, the effect of local cultural norms and availability of contraception.
The post you're replying to argues that Muslim immigration has raised fertility rates, and your numbers confirm that opinion. Even the falling Muslim fertility rates, after 15 years, that you mention are far above the "native" rates (2.9 as opposed to 1.7 in Holland, and you call the idea that Muslims raise fertility rates "horseshit"?!). The rates that you cite for Germany show a Muslim population that, even after 40 years, is growing at a rate of 20+% per generation, whereas the "native" population is declining.
To this decades-old immigration that is still growing strong, we must add recent immigrants, who are much more religious and have much higher fertility rates.
zeteo Muslim immigration into France accounts for the high fertility.
The second development to note is that INED, France's National Institute of Demographic Studies, has done some detailed research and concluded that France's immigrant population is responsible for only 5 percent of the rise in the birthrate and that France's population would be rising anyway even without the immigrant population.
France is an interesting and peculiar case, with lots of natalist policies and with laws impeding the collection of statistics based on religion and ethnic origin. I'd love to see the original INED study, though, if you have a link.
The quote uses terms like "Dutch-born" and "German-born." Do those terms include only Christian women who are ethnically Dutch or German? Or do those terms also include the second generation of women born in Holland and Germany, whatever their religion or ethnicity?
I just read the linked article at UPI. It is unclear on the matter.
It means born in the country. If they had meant Dutch or German ethnic they would have said so. So it's referring to people on the short road to assimilation.
It not religion per se that's becoming extinct in these nations, it's just some form of Christianity (usually, a very moderate and modernizing form). Detailed demographical studies show that fundamentalist religion (e.g. born again evangelicals and devout Muslims) is definitely on the rise, and associated with by far the largest fertility rates.
In addition, I think it's misleading to count "no affiliation" as "no religious beliefs."
What about new-age spirituality, alternative spirituality, etc.? Those typically don't show up in these kinds of studies, but they do qualify as religious beliefs.
Detailed demographical studies show that fundamentalist religion (e.g. born again evangelicals and devout Muslims) is definitely on the rise, and associated with by far the largest fertility rates.
Approximately three minutes after your reply came another reply
At the risk of sounding ignorant, I ponder correlation or a relationship, but furthermore whether the relationship has something to do with intelligence.
In my observation, intelligent people breed less. Intelligent people are also less associated with religion.
Could we also be looking at a list of countries with highest intelligence per capita?
This is a hard issue to analyze when most countries don't gather data on IQ that are comparable at all from country to country, and when there is considerable disagreement about what we mean by "religion."
It is becoming a firmly established research finding that rationality is weakly correlated with IQ,
with many high-IQ individuals exhibiting extremely poor rationality, so even if we knew differing IQ distributions for countries around the world reliably, which we do not, we would have no idea from those statistics which countries have a populace that tends to act rationally.
"Lack of religion is either non-adaptive from a fitness perspective, or it is strongly tied to traits which are themselves non-adaptive."
I think you're missing that population control within available resource constraints is also part of the fitness equation. Also it's very likely that population expansion or contraction is more cyclical over the long term than a two year period of data would show.
Biology isn't my strong suit, so I hope that I'm not misunderstanding you, but wouldn't your statement imply selection at the group level?
Additionally, although the figures I quoted were over a two-year figure, they exemplify a larger trend. For example, the Wikipedia article on Australia's demographics show that Australia hasn't had replacement level fertility since 1975.
My statement really should have been worded as a question as biology, admittedly, it is not my strong suit either so I won't attempt to address your question but hope that someone with a better understanding will chime in here.
This argument is just surreal. Are you claiming that the two are related? Why are fertility rates low in other countries not on the list as well? And in many countries, it's even lower. You never explicitly link the two together but you seem to be making some sort of implication that the trend of low fertility rates, which is more than anything related to the economical development of a particular country, is related to the lack of religiousness in the particular country.
But in general better education leads to more wealth, more time spend in schools and those who have college degrees are less likely to be religious and they are less likely to have children (the price of kids is low if they can help out on the farm, very high if you have to raise them in a modern society).
I don't know a good solution to this, but I suppose the problem with fix it self on way or another.
Look at fertility in France.
It's not because people here are highly religious, for sure.
Instead, the government simply put lots of programs into place to support family raising -- high-quality free daycare, long school hours (so both parents can get back to work and mothers don't have to sacrifice careers), hefty tax breaks per child, medical care (for birth & pre/post natal, but also pediatric care).
And (a bit more oddly) the medical care a mother gets after giving birth has a heavy focus on getting her back into shape for restarting her sex life -- it's standard to be prescribed a course of physical therapy to retrain the perineums of new mothers for exactly that reason.
All of these programs designed to help mothers keep working, etc. are not because at heart the French are feminists; they are not. Sexism is rampant. BUT they want mothers to have babies, so they figured out how to make that happen.
The system isn't perfect by a long shot, and it's not always ideal to have the state raise your kids as much as tends to happen here, but it's certainly quite successful: the birth rate is about 2 births per woman and slowly rising.
The birthrates of Muslim women in Europe have been falling significantly for some time. In the Netherlands, for example, the TFR among Dutch-born women rose between 1990 and 2005 from 1.6 to 1.7. In the same period for Moroccan-born women in Holland it fell from 4.9 to 2.9, and for Turkish-born women in Holland from 3.2 to 1.9.
In Austria, the TFR of Muslim women fell from 3.1 to 2.3 from 1981 to 2001. In 1970 Turkish-born women in Germany had on average two children more than German-born women. By 1996 the difference had fallen to one child and has now dropped to 0.5. These sharp falls reflect important cultural shifts, which include the impact of universal female education, rising living standards, the effect of local cultural norms and availability of contraception.
Falling, but still much higher than the 'native'. Also, the increased fertility rates of the second-generation immigrants are absorbed by these statistics into e.g. "Dutch-born", which skews the comparison.
> Instead, the government simply put lots of programs into place to support family raising
Those programs don't actually make raising kids cheaper. They just time-shift the payments, much like a loan would do.
Remember, govt programs are paid for by taxes. Those parents are being taxed.
Oh, and if we're going to argue for using govt money to buy kids, shouldn't we put the process out for bid? I'm sure that we could get high-quality kids for less from other suppliers.
I suggest that religions and fertility are both decreased by education and economic growth. So it could be "strongly tied to traits which are themselves non-adaptive".
This implies that "fitness" of a society is correlated positively to fertility rates, which for a species which is not exactly on the endangered list, and which is capable of producing results that can be measured on other scales than just warm bodies, seems to be a dubious idea.
Your argument would imply that the 10 "fittest" countries in the world are: Niger, Guinea-Bissau, Afghanistan, Burundi, Liberia, Democratic Republic of the Congo, East Timor, Mali, Sierra Leone, and Uganda.
I honestly don't understand your point. Humanity is not in danger of dying out from lack of fertility, Dutch (etc.) culture/genetic stock is not in danger of dying out from lack of fertility, and an argument from eugenetics is both dangerous and likely to be moot when genetic tinkering becomes widely accepted in a couple of generations.
(Also, e.g. country-level wealth is extremely non-adaptive according to your criterion. You may want to reconsider it.)
Yes, but so what? "Correlation != causation" != "no relationship so we can all just stop thinking about it". Whether it's causative, reverse causative, or two things caused by a shared third factor that may also have other effects, there's a there there that can't be waved away by a trite, fashionable two words and a math symbol. Careful reading of the "bottom line" winestock posted will show that (s)he actually understands this.
> Careful reading of the "bottom line" winestock posted will show that (s)he actually understands this.
This is incorrect. Winestock:
> Bottom line: Lack of religion is either non-adaptive from a fitness perspective, or it is strongly tied to traits which are themselves non-adaptive.
A third possibility, one of many, is "Lack of religion and a fertility rate less than 2.0 occur co-incidentally in seven countries". Given that we have only examined nine countries of a possible 195 (or so), I think that this third option is at least possible.
Accuracy of the data in question is a separate issue. My point was merely that the possibility of non-causation was covered. Inaccurate data is still not "correlation != causation" (it supercedes it).
Even if winestock compiled a complete list of 195 countries, their religiosity, and their fertility rates, and showed a correlation between them (which it seems is unlikely -- see for example steadicat's post, or my other post), it would still be wrong to conclude, as winestock did, that
> Lack of religion is either non-adaptive from a fitness perspective, or it is strongly tied to traits which are themselves non-adaptive.
There is at least one other possibility, which is that there is no link between religion and fertility, even transitively.
"Correlation != causation" is a warning sign not a stop sign.
If we find a correlation, then that's a sign that we should look deeper. So far, the evidence says that lack of religion is tightly connected with a drop in fertility. If something other than lack of religion is causing the drop then the best place to look for it is by checking those factors that are most common to the irreligious and least common among the religious.
If someone has done this research then I am unaware of it.
"Correlation != causation" is a warning sign not a stop sign.
I might add that for social causation issues like this, longitudinal data (studies of changes over time) are often much more informative than cross-sectional data (comparisons of different subgroups at the same time). You and the original submitter posted longitudinal data, studied by researchers who have a data model that they are further investigating. That's at least worth talking about here.
After edit: as several replies have helpfully noted, one way to test the proposed model is to look at data from other countries, and another way to test it would be to look at data from different (earlier) historical periods in the same or different countries. Much work needs to be done to accept the causal mechanism proposed in the submitted link, but meanwhile we can check the narrower issue of whether participation in organized religion has the same time trend (reduction over time) as fertility rates in various countries of interest.
A study which also attempted to model societies that weren't trending towards religious extinction be a lot more useful (the states were most likely chosen for readily available data rather than being selected due to being exceptional in their levels of religious disaffiliation). Right now I'm seeing a correlation between "nations which make detailed census data available in convenient form to academic researchers" and increasing levels of religious disaffiliation and low birth rates.
The same model would probably fit quite well to countries where there's a marked trend increase in a specific religious affiliation, like Indonesia where dominant and growing Islam may hypothetically be decades away from making other affiliations extinct. Does Indonesia have a correspondingly much higher fertility rate? Actually no (~2.28), especially not if you control for other variables like poverty and infant mortality that are known to be correlated with high fertility rates. And it's dropping.
So, what's your point? We have all had this ingrained in us since our first statistics class. Saying that correlation does not equal causation really says nothing. It does not agree. It does not disagree. The only thing this does is easily dismiss something of importance, which by definition has a connection to the discussion.
Correlation != causation is laziness at it finest.
Religion is a burden on society, a social trait from civilizations past, they lacked the vast majority of scientific knowledge we currently embrace, this "evolution" was bound to happen sooner or later.
Any rational intelligent being should quite clearly see the fundamental floors of all religions, how they act mearly as placebos at best; but primarily as precursors to wars, hours of wasted time per week on mundane rituals, dark ages, etc.
If all religions were gone tomorrow, the burden on society would still be there in another form. There are many people religious about global warming, Linux, the GNU, styles of politics and economics, etc. Even some political figures are followed religiously to a point (where logic and reason are out the door when you try to have a conversation questioning them).
Religion isn't all bad. There are people that take it to the extremes, but many of the things in the bible teach you to be a better person. I like Buddhism too.
..and we also can't forget that nobody can really prove either way about an afterlife, if god exists, if someone created our universe or it was always there.
Even the great Hari Seldon was unable to accurately turn mathematical models into true predictions of human society without the intervention of R. Daneel Olivaw.
No you have the wrong way round. Daneel (all though started with Giskard) was unable to accurately turn mathematical models intro true predications without Hari Seldon.
I looked at the paper (already kindly linked by bartonfink, but here it is again: http://arxiv.org/abs/1012.1375). I think there's considerably less to it than meets the eye.
The authors have a very simple model of the dynamics of religious adherence, which amounts to saying: people convert from one (ir)religious position to another in numbers proportional to some function of (1) the fraction of the population currently adhering to each position and (2) some measure of how attractive each position is. They assume that #2 is constant over time. They choose a particular (reasonably plausible) form for the dependency on #1. They have a couple of free parameters, which they adjust to make their predictions fit reality as well as possible. They plot a few graphs, which show their predictions fitting tolerably well.
They observe, quite rightly, that their analysis implies that on not-terribly-long timescales whichever position is more attractive will dominate completely. They fail to observe that since at present neither religion (any, or all collectively) nor irreligion is completely dominant anywhere, the attractivenesses must in fact be varying over time, and that future changes to that parameter make an enormous difference to their model’s predictions. They fail to consider the possibility that their model (even if generally adequate) may break down badly for small-minority positions. (If so, its predictions about extinction of any position could be very wrong.) They fail to consider that differences in personality, experiences, etc., may render (ir)religion differently attractive to different people, which could entirely change their model’s predictions near the edges. (That is, once it starts predicting that either religion or irreligion will go extinct or nearly so. That is, exactly the situation the headline describes.)
They do (and frankly this is the only interesting bit) consider the effect of clustering effects: a person’s conversion probability may depend not on the overall popularity of the "old" and "new" positions but on their local popularity: people are affected more by their friends, family, neighbours, colleagues, etc. They find that provided people aren’t completely isolated this doesn’t make a huge difference to the overall prediction of the model.
I don't think the paper gives much more reason to anticipate the extinction of religion than we already had. (Opinions vary as to how much that is...)
Remember that at some point in history being non-religious was either impossible or very underground. It could be that we're globally passing through a period of transition, from one stable uniformity to another.
I find this very interesting, and I hope that they get it peer reviewed somewhere so it's more "official" than arxiv. I don't normally view religion as a social activity, and this analysis seems to hinge on social factors (i.e. it seems to be counting edges instead of nodes). Religion doesn't seem to necessitate multiple people in the same way that language does, so I wonder whether their model might be fundamentally flawed. Looks like my pile of papers to read just got a couple pages higher.
The link to download the paper is here if anyone wants it.
I don't normally view religion as a social activity ... Religion doesn't seem to necessitate multiple people in the same way that language does
I believe there's some disagreement over whether religion is characterized as primarily a set of beliefs individuals hold, or primarily a sociological phenomenon. Clearly most religions have a mixture of both, so the disagreement is over which is more important or definitional. I think most sociologists tend to see it as more of a social phenomenon, with the role of shared beliefs being just one kind of social glue. Linguistically, we don't seem to call personal beliefs that one person holds, not shared by anyone else, a "religion"; religions seem to require some sort of community of members.
I fall more in the philosophical camp than the sociological camp with regards to religion, as I use the term to describe a subject of thought rather than a cultural institution, which is how your sociologists seem to be characterizing it.
I'm not sure that your linguistic argument holds in this case, because we're actually discussing the specifics of what "religion" means and so we can't appeal to standard usage. I, for instance, wouldn't call someone's personal beliefs on God a "religion" any more than I would call someone's personal beliefs on mental illness a "psychology" or their views on continental drift a "geography". In my mind, it just doesn't make sense for someone to possess a subject of thought.
If religion requires active participation in a community, then the existence of hermits who feel drawn to separate themselves from society to focus more on God seems to be a strong enough counterpoint that there's more going on. Like you say, there's disagreement about the term, but I'm just pointing out that this study only seems to make sense in a purely social way. People in these nine countries aren't going to stop thinking about God, death or any of the other usual subjects of religious materials, so I think calling for the extinction of religion is a bit premature.
I can't speak for the other countries, but private polling data in the United States reveals many more people who believe in a deity or who self-describe as "spiritual" than who are affiliated with an organized religious community by regular attendance at group meetings.
Christian scholars in the United States have noted that many self-described Christians do not have a set of doctrinal beliefs that accord with historic Christianity.
"Militant" or "fundamentalist" atheism are pejorative and wildly inaccurate, but I definitely think "evangelistic" atheism aptly fits the "New Atheist" movement. The precise term is probably "anti-religion", though.
Most of the irreligious in these nine nations are probably more apathetic or agnostic than actually atheist, much less evangelistic atheist.
I'm of the opinion that as man understands more about the world and how to actually control it (through science and technology) that his reliance or use for religion will fall.
It'd be interesting to see a study on that, because I think uncertainty (about anything) ... is a space in the human psyche that is filled by Religion.
I'm unaware of any collection of humans in history that did not practice some form of religion. I suspect that religion will become extinct only when we humans do too.
You're right that religion seems to be a human universal. I believe that every human population ever studied practices it in some form or another.
But, what may be declining is not religion per se, but rather monotheism. Zoroastrianism, one of the first monotheistic religions, emerged only in the 2nd century BCE. For the entirety of human history before that, about 200 millennia, humans practiced some form of nature worship, ancestor worship or polytheism.
It may be that the age of monotheism is coming to an end, but what comes next is anyone's guess.
2nd Century BC? What about the Jews? While exact dates are not very well known, Jerusalem was invaded around 600 BC. The dead sea scrolls have been dated back to well before the 2nd Century BC.
You're right, my mistake. I had it in my head that Zoroastrianism was first, then looked up its origins to get a date, but didn't double-check it. It looks like Judaism pre-dates Zoroastrianism by a couple centuries, and Atenism (emerging in the 14th century BC) preceded both.
The argument still stands. We're still talking about 4 millennia of monotheism, preceded by 200 millennia of various other forms of religion.
I've always thought religion would become less and less prevalent. Being non-religious was extremely rare before evolution was discovered and now its growing in popularity since we now know more, i think that trend will continue.
Evolution has had about 150 years, religion has had multiple thousands of years. In my opinion its just a matter of time before religious belief becomes a minority everywhere.
What do we know? That one species can evolve into another? Never been remotely proven. That one species can adapt itself to its surrounding. Sure that happens. It doesn't change its species though. "Macro" evolution just doesn't happen nor can it be proven to have happened.
And you're basing your claims of no evidence on...? I study evolution and genetic variability in populations of a certain algae, and have data from the last 20 years from across the country (not the person who took it 20 years ago though) to say that a population doesn't evolve would be absurd. What about genetic drift? What about species isolation? What about changes in a population that prevent sexual reproduction with the rest of the species? The truth of the matter is, there is a plethora of data supporting evolution.
Even assuming your claims were true, what, are we supposed to accept the religious explanation as more plausible? Because not only has that never been proven, it's a lot harder to swallow in the first place, which means we should expect even more evidence that it's true before we take it seriously.
And besides. It's pretty much rock solid that one species can evolve into another, or at least that multiple current species sprang from single earlier species. When you look at genetic data across living things, the signs of a tree-like structure are absolutely fucking unmistakable.
Sure, it's not a trivial problem to actually extract the entire tree of life (see http://en.wikipedia.org/wiki/Phylogenetics - the difficulty is that we only get to touch DNA from the leaves of the tree, and we have to infer the rest), but the tools biologists use are more than powerful enough to distinguish a set of leaves that likely came from an underlying but hidden tree structure from "leaves" that came about in some other way. I don't know numbers off the top of my head, but IIRC from conversations I've had with bioinformatics folks the confidence levels are extremely high, the only debate is over which particular tree should be inferred from a given set of leaves.
Take species A. For whatever reason, species A splits into two groups, A1 and A2. A1 and A2 are (initially) the same species, but the split causes them to be separated for a long time (hundreds, thousands, tens-of-thousands, hundreds-of-thousands, millions of years).
You have already accepted that A1 and A2 will adapt to their surroundings. What prevents those adaptations from eventually making A1 and A2 no longer able to mate?
These nations have always been prosperous and secularized- this doesn't exactly sound like startling use. The decline of religion as a social institution in these countries will not forestall the existence of bigotry, irrationality, and folly- those are all inevitable problems of human nature.
People are realising more and more that it's ones self who is in control and do not need to channel their willpower thru an external entity to make things happen / hope that things will go well. Same thing being that it's modern medical science that extends people's lifetime and cures illness, Education that teaches us evolution, Etc, Etc.
Besides, Everything has a beginning and an ending so it's hardly surprising.
For everything else there's the dream of "The Empathic Civilisation".
As far as I can tell, they're defining "religious" as people claiming to be religious, and "non-religious" as people claiming no religious affiliation. So they're assuming that everyone means the same thing by the word "religion", and that these people's unspoken definition is a useful concept.
Atheists like to talk about the harm done by "religion". But this harm might be done by deeper habits of thinking that will persist in people who identify in surveys as "non-religious".
I hope so. I'm seeing strong men and theocracies crumbling the middle east. I'm seeing proud gay men and women demanding basic humans rights in the west. I'm seeing a social acceptance of being non-religious. I'm seeing religious bigots think twice before spewing their hatred in the workplace. I'm seeing young people questioning the faith of their parents. I'm seeing basic science like evolution taught to more and more people everyday. Even while the religious do their best to fight this EVERY STEP OF THE WAY.
The casual hatred that religion breeds is at least being challenged. 1st century cosmologies may never collapse,but they're moving more towards the low-information and undereducated types everyday. I'm not sure what the future holds, but the trend looks good.
I'm also seeing plenty of great citizens and neighbors who live what they believe. I see people drawing strength and happiness from their faith. I see people in the darkest stages of their life escape only after gaining that faith. I see religious organizations helping people to donate their time and effort to improving the world both locally and globally. I see good things coming from religion.
Blinders are incredible things. People like you remind me of the average North Korean citizen. Even when presented with proof of Dear Leader's abuses, they will deny it and continue to love him and defend his regime to the death.
I found it weird that they claim to have used census data from the Netherlands. The last census in the Netherlands was 40 years ago (http://www.volkstellingen.nl/en/) I would hope they used other sources (data from the CBS (Central Bureau of Statistics) would be the primary candidate)
"The study found a steady rise in those claiming no religious affiliation." No religious affiliation does not mean people are becoming non-believers. I hear a lot of people who believe (in whatever) but don't want to be marked as religious.
In many cultures, it's quite a binary thing. Either you believe in religion or you believe in science. They are viewed to be entirely incompatible (which they aren't). People who have a belief in a higher power often feel unwilling to label themselves as believers because they don't want to be discriminated against as ignorant and bigoted.
Go to Wikipedia and search for "Demographics of X" where X is a nation from the list given in the above-linked article: Australia, Austria, Canada, Czech Republic, Finland, Ireland, the Netherlands, New Zealand, and Switzerland.
(Nation/ Total Fertility Rate) (Australia/ 1.97) (Austria/ 1.41) (Canada/ 1.58) (Czech Republic/ 1.49) (Finland/ 1.85) (Ireland/ 2.1) (Netherlands/ 1.66) (New Zealand/ 2.1) (Switzerland/ 1.46)
Those numbers are for the years 2007 to 2009, depending on the nation. Note that only Ireland and New Zealand are at replacement levels. Residual Catholic natalism may explain Ireland's current fertility (given their loss of religion, don't expect that to last). Reading between the lines in the Wikipedia article for New Zealand, it seems that the Maori and Pacific Islanders are doing more than their fair share of baby-making. My guess is that they are more religious than the contracepting whites.
Bottom line: Lack of religion is either non-adaptive from a fitness perspective, or it is strongly tied to traits which are themselves non-adaptive.
UPDATE: I can't get the formatting right on that table of fertility rates.