The
demographic transition describes how rich countries often wind up with sub-replacement fertility levels. To sustain their populations each woman needs to have at least two children. Yet in Japan, the fertility rate is 1.4. In South Korea, it is 1.3. In Hong Kong, it is 1.2. In Taiwan it is 1.1. For more stats on this see
here.
This is a bit of a puzzle for the "at all boils down to DNA genes" versions of evolutionary theory (i.e. most sociobiology and evolutionary psychology) - since basic theory predicts that the more resources you give an organism, the more offspring they are expected to have.
The standard memetic explanation for this is that memes compete with genes for resources and act to divert host resources from making more DNA genes to making more memes. Dawkins gave essentially this explanation in 1976, referring in particular to the low fertility of priests - and how their resources were being directed away from gene propagation and into meme propagation.
Conventional explanations of the phenomena observe that famale choice is involved. Years of college education in girls is strongly negatively correlated with fertility. Educated girls are waiting longer before having kids and are then having fewer of them. Another fairly obvious factor is cheap family planning technology.
There are some explanations that don't involve memes. For example the r/K selection axis is fairly clearly involved - and it is possible that some environments act as superstimulii for faculative K-selection mechanisms - producing a maladaptive response. Faculative K-selection mechanisms are certainly part of the story, but they are more like one of the targets that the memes use to effect their results than the main story.
I think the main mechanism is that influential female role models tend to be those who have prioritised meme reproduction over their DNA genes. While mothers are busy raising their children they have less time and resources available for influencing others.
On the other hand, take Jennifer Aniston, for example. Apparently she has said: "I've never in my life said I didn't want to have children. I did and I do and I will... I would never give up that experience for a career." However, somehow or another she still doesn't have any kids. Women who have prioritized their career over having kids are more likely to be publicly-visible role models - leading to a meme-driven plague of female infertility.
I am fascinated by self-conscious expressions of this tendency. Steven Pinker provided me with some early examples:
Well into my procreating years I am, so far, voluntarily childless, having squandered my biological resources reading and writing, doing research, helping out friends and students, and jogging in circles, ignoring the solemn imperative to spread my genes.
...and...
By Darwinian standards I am a horrible mistake, a pathetic loser, not one iota less than if I were a card-carrying member of Queer Nation. But I am happy to be that way, and if my genes don't like it, they can go jump in the lake.
Dawkins famously wrote:
We are built as gene machines and cultured as meme machines, but we have the power to turn against our own creators. We, alone on earth, can rebel against the tyranny of the selfish replicators.
Keith Stanovich turned this into a manifesto, with his book: The Robot's Rebellion: Finding Meaning in the Age of Darwin.
Evangelical approaches to the issue are of particular interest. For example consider Richard Stallman's essay:
Why it is important not to have children. Richard starts out provocatively with:
The most important thing you can do, to avoid global disaster and make a positive contribution to the world, is avoid having children.
He goes on to explain:
Overpopulation is a tremendous danger to civilization and the ecosphere. It makes every human-caused ecological problem bigger. Population growth has slowed but not stopped. The human population is expected to grow by 2 or 3 billion by 2050, and it is not clear how to find water and food for all those people. Population growth also increases the difficulty of curbing global heating. Thus, the decision about having children is, for most people, the most important decision in their lives about how they will affect humanity's resource footprint in the future.
Others have also put a moral spin on the issue.
David Benatar's "Better Never to Have Been: The Harm of Coming into Existence" argues that having kids is always bad because it introduces more suffering into the world.
Andrés Gómez Emilsson recently wrote:
Your selfish genes will try to do everything they can to make you feel like not reproducing is the same as dying and going to hell. For the love of God, do not listen to your selfish genes.
Dawkins (again) wrote:
"As for me, I'd rather spread memes than genes anyway.
One of the biggest modern anti-Natalist experiments was the Chinese "one child" policy - which made having multiple kids illegal.
I am more pro-natal than anti-Natal. I'm not especially evangelical on the issue, though I do describe some of the anti-natalists as being "pro-death" and generally warn against their influence.
I think Stallman is mistaken in thinking that more people will make the world worse. I am more with Julian Simon in The Ultimate Resource - more people are better. China looks set to be a big force in the 21st century. Their secret is that they have more people - and that means more scientists, engineers and other folk that make the world a better place. Overpopulation seems like a very distant hazard to me - the carrying capacity of the planet is clearly enormous.
Underpopulation is much more serious problem. This century is likely to see "peak human" - as people spend more and more time in computer-generated environments and in the company of sexbots and virtual catwomen. As machines rise, the human gene pool is likely to falter and then fall. Anti-natalism will be part of how it happens. I generally favour slow transitions over fast ones. I don't think procreation will save the humans from being made redundant by technology, but lack of procreation could lead to a more rapid demise for humans, and a rapid transition increases the chance of important information getting lost during the transition.
As for the moral dimension of Darwinism, that debate dates back to Huxley and Kropotkin. Huxley argued that nature was bad:
From the point of view of the moralist the animal world is about on a level of a gladiator’s show. The creatures are fairly well treated, and set to fight – whereby the strongest, the swiftest, and the cunningest live to fight another day. The spectator has no need to turn his thumbs down, as no quarter is given. [...] But, in civilized society, the inevitable result of such obedience [to the law of bloody battle] is the re-establishment, in all its intensity, of that struggle for existence – the war of each against all – the mitigation or abolition of which was the chief end of social organization.
...while by contrast, Kropotkin saw evolution as leading to cooperation and morality. My position is much more on Kropotkin's side than Huxley's. Yes, evolution has produced some suffering, but give it a chance: it hasn't finished booting up yet.