Yes, obviously thermodynamics limits exponential growth. I’m saying that exponential growth won’t continue indefinitely, that people (unlike bugs) can, will, and in fact have already begun to voluntarily curtail their reproduction.
Yeah, this obviously matters a lot. Right now low to non-existent outside the People’s Republic of China, though I suppose that could change. There are a lot of barriers to effective enforcement of reproductive prohibitions: incredibly difficult to solve cooperation issues, organized religions, assorted rights and freedoms people are used to. I suppose a sufficiently strong centralized power could solve the problem though such a power could be bad for other reasons. My sense is the prospects for reliable enforcement are low but obviously a singularity type superintelligence could change things.
I’m not quite sure that penalties are that low outside China.
There are of course places where penalties for many babies are low, and there are even states that encourage having babies — but the latter is because birth rates are below replacement, so outside of our exponential growth discussion; I’m not sure about the former, but the obvious cases (very poor countries) are in the malthusian scenario already due to high death rates.
But in (relatively) rich economies there are non-obvious implicit limits to reproduction: you’re generally supposed to provide a minimum of care to children; even more, that “minimum” tends to grow with the richness of the economy. I’m not talking only about legal minimum, but social ones: children in rich societies “need” mobile phones and designer clothes, adolescents “need” cars, etc.
So having children tends to become more expensive in richer societies, even absent explicit legal limits like in China, at least in wide swaths of those societies. (This is a personal observation, not a proof. Exceptions exist. YMMV. “Satisfaction guaranteed” is not a guarantee.)
The legal minimum care requirement is a good point. With the social minimum: I recognize that this meme exists but it doesn’t seem like there are very high costs to disobeying it. If I’m part of a religion with an anti-materialist streak and those in my religious community aren’t buying their children designer clothes either… I can’t think of what kind of penalty would ensue (whereas not bathing or feeding your children has all sorts of costs if an outsider finds out). It seems better to think of this as a meme which competes with “Reproduce a lot” for resources rather than as a penalty for defection.
Sure, within a relatively homogeneous and sufficiently “socially isolated”* community the social cost is light.
(*: in the sense that “social minimum” pressures from outside don’t affect it significantly, including by making at least some members “defect to consumerism” and start a consumerist child-pampering positive feedback loop.)
I seem to think that such communities will not become very rich, but I can’t justify it other than with a vague “isolation is bad for growth” idea, so I don’t trust my thought.
Do you have any examples of “rich” societies (by current 1st-world standards) which are socially isolated in the way you describe? (Ie, free from “consumerist” pressure from inside and immune to it from outside.) I can’t think of any.
I’m not sure I understand what you mean. This isn’t a matter of interpersonal communication, it’s just individual married couples more-or-less rationally pursuing the ‘pass on your genes’ mandate by maximizing the survival chances of one or two children rather than hedging their bets with a larger number of individually-riskier children.
If a gene leads to greater fertility rates with no drop in survival rates, it spreads. Similarly if a meme leads to greater fertility with no drop in survival rate and is sufficiently resistant to competing memes it too spreads. Thus, those memes/memetic structures that encourage more reproduction have a selection advantage.
I don’t really think your characterization of the global drop in fertility rate is right (farmers with big families survive just fine!) but that isn’t really the point. The point is, mormons aren’t dying and neither are lots of groups which encourage reproduction among their members. Unless there are a lot of deconversions or enforced prohibitions against over reproducing the future will consist of lots of people whose parents believed in having lots of children and those people will likely feel the same way. They will then have more children who will also want to have lots of children. This process is unsustainable.
I’m expecting a lot of deconversions. Mormons already go to a lot of trouble to retain members and punish former members, which suggests there’s a corresponding amount of pressure to leave. Catholics did the whole breed-like-crazy thing, and that worked out well for a while, but catholicism doesn’t rule the world.
I think the relative zeal of recent converts as compared to lifelong believers has something to do with how siblings raised apart are more likely to have sexual feelings for each other, but that’s probably a topic for another time.
Yes, obviously thermodynamics limits exponential growth. I’m saying that exponential growth won’t continue indefinitely, that people (unlike bugs) can, will, and in fact have already begun to voluntarily curtail their reproduction.
What kind of reproductive memes do you think get selected for?
How strong is the penalty for defection?
Yeah, this obviously matters a lot. Right now low to non-existent outside the People’s Republic of China, though I suppose that could change. There are a lot of barriers to effective enforcement of reproductive prohibitions: incredibly difficult to solve cooperation issues, organized religions, assorted rights and freedoms people are used to. I suppose a sufficiently strong centralized power could solve the problem though such a power could be bad for other reasons. My sense is the prospects for reliable enforcement are low but obviously a singularity type superintelligence could change things.
I’m not quite sure that penalties are that low outside China.
There are of course places where penalties for many babies are low, and there are even states that encourage having babies — but the latter is because birth rates are below replacement, so outside of our exponential growth discussion; I’m not sure about the former, but the obvious cases (very poor countries) are in the malthusian scenario already due to high death rates.
But in (relatively) rich economies there are non-obvious implicit limits to reproduction: you’re generally supposed to provide a minimum of care to children; even more, that “minimum” tends to grow with the richness of the economy. I’m not talking only about legal minimum, but social ones: children in rich societies “need” mobile phones and designer clothes, adolescents “need” cars, etc.
So having children tends to become more expensive in richer societies, even absent explicit legal limits like in China, at least in wide swaths of those societies. (This is a personal observation, not a proof. Exceptions exist. YMMV. “Satisfaction guaranteed” is not a guarantee.)
The legal minimum care requirement is a good point. With the social minimum: I recognize that this meme exists but it doesn’t seem like there are very high costs to disobeying it. If I’m part of a religion with an anti-materialist streak and those in my religious community aren’t buying their children designer clothes either… I can’t think of what kind of penalty would ensue (whereas not bathing or feeding your children has all sorts of costs if an outsider finds out). It seems better to think of this as a meme which competes with “Reproduce a lot” for resources rather than as a penalty for defection.
Your observation is a good one though.
Sure, within a relatively homogeneous and sufficiently “socially isolated”* community the social cost is light.
(*: in the sense that “social minimum” pressures from outside don’t affect it significantly, including by making at least some members “defect to consumerism” and start a consumerist child-pampering positive feedback loop.)
I seem to think that such communities will not become very rich, but I can’t justify it other than with a vague “isolation is bad for growth” idea, so I don’t trust my thought.
Do you have any examples of “rich” societies (by current 1st-world standards) which are socially isolated in the way you describe? (Ie, free from “consumerist” pressure from inside and immune to it from outside.) I can’t think of any.
Mormons?
I’m not sure I understand what you mean. This isn’t a matter of interpersonal communication, it’s just individual married couples more-or-less rationally pursuing the ‘pass on your genes’ mandate by maximizing the survival chances of one or two children rather than hedging their bets with a larger number of individually-riskier children.
If a gene leads to greater fertility rates with no drop in survival rates, it spreads. Similarly if a meme leads to greater fertility with no drop in survival rate and is sufficiently resistant to competing memes it too spreads. Thus, those memes/memetic structures that encourage more reproduction have a selection advantage.
In this case, the meme in question leads to a drop in fertility rates, but increases survival rates more than enough to compensate.
I don’t really think your characterization of the global drop in fertility rate is right (farmers with big families survive just fine!) but that isn’t really the point. The point is, mormons aren’t dying and neither are lots of groups which encourage reproduction among their members. Unless there are a lot of deconversions or enforced prohibitions against over reproducing the future will consist of lots of people whose parents believed in having lots of children and those people will likely feel the same way. They will then have more children who will also want to have lots of children. This process is unsustainable.
I’m expecting a lot of deconversions. Mormons already go to a lot of trouble to retain members and punish former members, which suggests there’s a corresponding amount of pressure to leave. Catholics did the whole breed-like-crazy thing, and that worked out well for a while, but catholicism doesn’t rule the world.
I think the relative zeal of recent converts as compared to lifelong believers has something to do with how siblings raised apart are more likely to have sexual feelings for each other, but that’s probably a topic for another time.