I think there is much more to be done improving (from the standpoint of the future of humanity) the children of others than creating new ones yourself.
Sometimes the non-child-creators justify their decision by suggesting that the projects they are working on are especially socially valuable and thus they can spend time on them in preference to child-creation without violating their duty to society. While it is possible that this argument goes through in some cases, it seems suspiciously self-serving. What is especially worth taking into account is that if the humans in question really are so highly valuable, they would statistically have highly valuable offspring. Thus, it seems doubtful in the general case that high-value people refraining from procreating is a net gain for society.
Actually, your argument seems suspiciously own-gene serving. And it is the optimization power and direction of genes from which our ability for self-deception comes. You said yourself "A duty to society is typically not the only or primary reason for why people decide to have children." Could it be that the instincts that have driven you to procreate make having children enjoyable enough to justify being "knee-deep" in poop in your mind, and you are portraying it as self-sacrifice just to look virtuous?
If procreation to create especially valuable-to-society children for the good of humanity is such an important goal that you feel fit to criticize people for sitting out as "freeloaders", then have you and your mate used your own sperm/eggs to create these children, or have you bought sperm/eggs with the best genes available? The answer will reveal which agent is really holding the reigns here. (If the former, either you and your mate have the best genes available (from the standpoint of the future of humanity, which is unlikely) or it's your genes holding the reigns, and this idea that you're selflessly giving up your freedom for the good of humanity is the creepy goatee'd advisor standing next to the king saying "A most judicious choice, sire!").
To add to this, there is nothing mandating that the same number of humans that exist now are required in the future for human civilization to work. Especially, as productivity has gone up in recent decades, humanity could now probably exist at the same level of prosperity of the latter 20th century with half the population it has now.
And of course, the whole premise of this site is that AIs have the capability to render this entire argument moot. In principle, if a FAI can be created, we can all rest peacefully and retire, and no longer will a younger generation be required. Of course things get complicated in practice. That's why you can't make the argument 'we need more children!'
To add to this, there is nothing mandating that the same number of humans that exist now are required in the future for human civilization to work. Especially, as productivity has gone up in recent decades, humanity could now probably exist at the same level of prosperity of the latter 20th century with half the population it has now.
Maybe we decide each couple should ideally have 1.7 children, maybe 2.3. The point still stands that some children need to be reared and it is, all things being equal, your duty to do your part in this.
all things being equal, your duty to do your part in this.
One can 'do their duty' by being a good person and contributing to society, thus helping other people's children grow up. But then, most people already do try to contribute to society, and in wealthy countries (which your criticism seems to be aimed at) the system appears to be working well and allowing the support of new children as it stands, so it's not like any extra effort is needed on society's part.
By the way, just to clarify, I'm not saying people should work so that other people can have kids. All I'm saying is that this is a hole in your argument. Someone who doesn't bear children is not necessarily a freeloader.
One can 'do their duty' by being a good person and contributing to society, thus helping other people's children grow up.
This is like saying "I'm going to evade paying taxes, I'll just contribute to society in other ways". This might work, you might even come out ahead, but you are prima facie being a freeloader.
I don't see how this would be any different from any of the billion other possible game-theoretic freeloader problems.
By this logic, all the possible freeloader things that you're doing (i.e. the contributions you're not giving that some large number of other people are giving) are also worth consideration relative to their potential or possible value to society. Have you watered a plant today? Have you walked to work instead of using a car today? Have you saved someone's life today? Have you taught someone something useful today? Have you marginally assisted in future scientific and technological advances today? Or all of those things this hour? This minute? No? Because there's a lot of people out there who have, you freeloader! Sure, you might say you're prioritizing other things, that you're trying to contribute in other, better ways. This might work, you might even come out ahead, but you are prima facie a horrible being that causes all sorts of headaches for Game Theorists worldwide.
Now please proceed to ignore me and accuse people of freeloading on this particular problem that you think is more important than the other ones.
I have nothing against division of labor. Not everyone needs to be a farmer. But you can't effectively farm children so we need most people to pitch in. This is a volunteer system very unlike growing plants. If you grow plants and sell them to me then I'm not a freeloader. But if you raise children then I don't pay you for them, yet I still benefit. That's where the freeloader part comes in.
Now please proceed to ignore me
Why? I'm assuming this is some sort of sarcasm rather than an honest request, but please clarify if this is not the case. If it was sarcasm, what was it motivated by?
Why? I'm assuming this is some sort of sarcasm rather than an honest request, but please clarify if this is not the case. If it was sarcasm, what was it motivated by?
The possible interpretation as sarcasm was intentional; the phrasing was intended to trigger a game board favorable to me in game-theoretic terms (i.e. provoke a "catch-22" where I win, in simple terms):
If you take my request seriously or otherwise do ignore me, I'm instinctively and emotionally content in the knowledge that I've uselessly thrown words at someone on the Internet I disagree with, which is something I've done many times before and am now comfortable with. The less reasonable parts of my brain are satisfied that you've done as I said, that I'm in control and not socially at risk. The more reasonable parts... well, acceptable expected utility gamble which happened to result in a minor negative outcome instead of a minor positive one, and I still got my initial entertainment and mental exercise from writing the comment.
If you take it as sarcasm or as some sort of challenge and decide to engage with me in an intellectual discussion about the game-theoretic issues, the cost analyses, or even just why you think these particular issues are more relevant and important and others can be discarded, then I've made progress and we're now in a more interesting (for me) part of the discussion where I believe we are closer to a satisfying conclusion.
Of course, I was somewhat betting that one of those two would be chosen, at some risk of unexpected divergence. Possibly also at some cost to you in the form of ego hit or something. However, unexpected divergences include this one, where you ask me about my choice of words, and I believe this is of positive value. To be honest, writing the above was quite fun. Plus you simultaneously went for one of those favorable options. Quite a success.
Now on to the actual topic at hand:
Various use-of-words arguments could be made regarding the non-volunteer versus volunteer aspects of human-making and other socially-beneficial endeavors, but more interesting and is the point about effective children-farming: Effective to what metric?
My mental model of Quality-Adjusted New Humans takes a few high-quality humans randomly spawned in a large number of new humans all living in a ceteris paribus better environment to be far superior to a marginally higher high-low new human quality ratio in a lower quality environment. As such, I think it's more efficient and beneficial to have experts focus on improving the environment at the expense of this low amount of potential parents being lost.
In practice, the above translates to: First-world, educated, high-quality people such as might be expected to participate on LW would benefit society more if they focus on creating a better society for the new humans to grow in, as opposed to adding a marginal number of high-expected-quality-adjusted-new-humans.
Which all probably relates to my priors about the impacts of Nature VS Nurture and my priors about the cost-benefits of one high-quality human versus many low-quality humans.
And on the other end of the inference chain, this leads to my conclusion that we should not recommend that LW participants and other audience members focus on producing children, with the corollary (but separate) points about where I do think they should focus their efforts.
That was an awesome answer, which leaves me with very little to add. I'll merely say that—as you've already implicitly predicted—what seems to be going on is that my nature/nurture priors are significantly different from yours and this leads us to such different conclusions.
.That was an awesome answer, which leaves me with very little to add. I'll merely say that—as you've already implicitly predicted—what seems to be going on is that my nature/nurture priors are significantly different from yours and this leads us to such different conclusions.
And there's the satisfying conclusion. Our priors are uneven, but we agree on the evidence and our predictions. We can now safely adjourn or move on to a more elaborate discussion about our respective priors.
As an important data point, my wordgaming experiments rarely work out this well, but so far have retained net positive expected utility (as do, unsurprisingly, most efforts at improving social skills). I'll bump up this tactic a few notches on my mental list.
If procreation to create especially valuable-to-society children for the good of humanity is such an important goal that you feel fit to criticize people for sitting out as "freeloaders"
The part about especially valuable children was two sentences and meant as a response to a potential objection, not as my main point. Parents in general are getting the kudos in this story, not just parents raising some hypothetical super-babies.
then have you and your mate used your own sperm/eggs to create these children, or have you bought sperm/eggs with the best genes available?
As you have correctly surmised, my instincts badly rebel against the idea of raising other people's children as if they were my own. Instincts like that could probably be surpressed with upbringing designed for that and maybe a utilitarian case could be made for such a policy. Or maybe not, I don't know, there are some really complex questions in there. But really, this wasn't supposed to be about eugenics - just about doing your part in some necessary work that we all benefit from.
the creepy goatee'd advisor standing next to the king saying "A most judicious choice, sire!"
That's exactly the guy I want to be. I'd like to convince the reader that following his or her biological instincts on this happens to be the noble thing to do. I do think the intellectual case for this is strong.
The part about especially valuable children was two sentences and meant as a response to a potential objection, not as my main point. Parents in general are getting the kudos in this story, not just parents raising some hypothetical super-babies. [...] I do think the intellectual case for this is strong.
In a world where we worry about overpopulation the case you brought is extremely weak. If you look at a previous discussion on the issue on LW there are two sides: "(1) Overpopulation is one of the most important issues and we have to do more to fight it. (2) We can be confident that the problem solves itself over time."
You are basically claiming that we need more overpopulation without providing arguments why. The only way to fix this is to assume that you aren't really meaning that you want more overpopulation and instead advocate that specific people should procreate.
You are basically claiming that we need more overpopulation without providing arguments why.
That's not what I'm saying at all. There is nothing in my post or my subsequent comments about needing to increase the population. We don't need new humans because we have too few humans - we need new humans because old humans die.
You might say that the human population as a whole is already breeding at more than replacement level and so any suggestion that someone should have children is de facto an encouragement to overpopulate more. I do have particular counterarguments to that (including the quasi-racist stuff you'd expect) but it's also just a turn in the conversation I didn't anticipate at all.
Alice: It would be nice if you drove to the store and picked up the cake for birthday. Bob: You are basically claiming that we need more carbon in the atmosphere without providing arguments why. In a world where we worry about global warming the case you brought is extremely weak. Alice: ???
Bob may well have a point but Alice is understandably confused.
When I wrote my post I anticipated the counterarguments against it and prepared answers for them. But no-one has even brought those counterarguments yet - everyone's talking about other things. What I think has happened is that I severely underestimated the inferential distance between my position and that of the typical reader. The great illusionist strikes again. I'll present this very differently next time.
(Btw, I didn't downvote you.)
There is nothing in my post or my subsequent comments about needing to increase the population. We don't need new humans because we have too few humans - we need new humans because old humans die.
Policy are supposed to get judged by real world effects. If we want a certain number of new humans those people who want to go through the experience of childbearing should start producing children. In the present world those already produce too much children, so there no case of the people who don't want to produce, to produce.
I do have particular counterarguments to that (including the quasi-racist stuff you'd expect) but it's also just a turn in the conversation I didn't anticipate at all.
Giving that you do point to the quasi-racistic stuff you are basically holding the position that not everyone should get children but that the right people should as Mestroyer said.
In that case you just disagree with him about who the right people happen to be. He thinks it's about being intelligent and the type of person who goes on lesswrong while you might also want more of stupid people that share your racial identification.
Without restricting the arguments to being about the right people getting more children the case is easily dismissed in a world with overpopulation. In the spirit of fixing the arguments of other people it makes sense to treat you as saying that you want the right people getting more children even if you don't explicitly say so.
Gah, no, that's not it at all. It feels like we're moving farther, rather than closer, to understanding each other's position.
I seem to have irreparably placed us on a wrong track with my post so I think I'll stop trying to recover from it. To make progress it would be best to start again from the ground up with a completely different write-up of my core idea. But for now, at least, I'll let this rest.
Could it be that the instincts that have driven you to procreate make having children enjoyable enough to justify being "knee-deep" in poop in your mind,
Yes, of course.
and you are portraying it as self-sacrifice just to look virtuous?
Meh. I could have made a much more convincing post to make myself look virtuous. Perhaps I should have. But I do want to encourage the reader to see childrearing as virtuous.
Actually, your argument seems suspiciously own-gene serving.
Well, I'm done having children - I'm hoping to induce other people to have children. Other people with genes somewhat similar to my own, you might say, and I won't protest.
When I wrote this post I realized that it had the potential flaw of appearing like I was primarily interested in bragging or complaining about my own decisions/situation. Your comment reveals to me that this flaw was more serious than I had thought. A better strategy might have been to write about friends of mine who have children and compare their lives with that of acquaintances without children. That way I could have gotten in the poop stuff without the annoying holier-than-thou effect. Thank you. [Edit: I removed the personal part for now.]
Without taking a stance on the original proposition, this argument sounds like "If you don't optimize perfectly for X, you don't really care about X".
My argument is more like: If our prior says almost everyone optimizes for Y, and few optimize for X, but many people like to say they optimize for X, and you point to an action A you have taken which increases X and say "Look how I'm optimizing for X!" and A increases Y as well, and there is an obvious alternative B which an X-optimizer would have noticed and which increases X more than A at the cost of not increasing Y, then we've just explained away A as evidence that you optimize for X and should stop privileging that hypothesis.
Edit: one more thing is important here, which is that A is something you'd do if you were optimizing Y, not just something you'd only do if you were jointly optimizing X and Y. You might be thinking "Well, just donate sperm/eggs!". But that is not an option that the Y-agent controlling the Thread Starter really "considers", because the selective forces that shape parental instincts did most of their work before the presence of that option.
Depending on how you define "care", maybe you can care about X without optimizing for it, but that doesn't really matter to me, as that kind of caring doesn't do X any good.
Current system for producing new humans has severe bugs — notably, it causes short-term (and sometimes long-term) disability to half the current humans involved in the project. Please fix.
Yeah, no kidding. My wife has rheumatoid arthritis which seems to have been triggered by the hormones involved.
The new humans can provide us with the assistance we need as our own abilities diminish.
So, a Ponzi scheme on a grand scale?
We have a surplus of people engaging in creating new humans. World population rises and there nothing wrong with having half as many people. In fact it might even help with a lot of issues such as global warming.
There also a second issue. You speak like dying of old age is inevitable. I much rather focus on solving that issue than focusing on producing more kids.
I much rather focus on solving that issue than focusing on producing more kids.
People continue to speak as if having kids funges mostly against high-minded projects. For most people, even most LWers, I think it will funge mostly against leisure.
For most people, even most LWers, I think it will funge mostly against leisure.
That assumes that my leisure time doesn't interact with high-minded projects. Posting on Lesswrong is a leisure activity for myself. While engaging in it I do learn things that are relevant to high-minded project and have a chance to contribute ideas to high-minded projects.
Giving quantified self media interviews is also an activity that you could call leisure by the definition that Wikipedia uses: "Leisure, or free time, is time spent away from business, work, and domestic chores."
I'm in a position where I gave a bunch of those interviews and I did turn down my last interview request for a radio interview.
There are a lot of tasks that do contribute to high-minded projects that you can't do in a way where it's business/work and you get payed for it.
Posting on Lesswrong is a leisure activity for myself. While engaging in it I do learn things that are relevant to high-minded project
Yes. You'd also learn relevant things from raising children and many aspects of the experience are even pleasant.
There are a lot of tasks that do contribute to high-minded projects that you can't do in a way where it's business/work and you get payed for it.
Exactly.
Yes. You'd also learn relevant things from raising children and many aspects of the experience are even pleasant.
I don't think that there are no advantages to having kids and I don't judge people for thinking that getting children is a good use of there time.
As far as learning relevant things goes, a lot of the lessons of child rearing are learned by many people. Most of the time it's much easier to learn relevant things when you focus your attention on an area that isn't well explored by other people.
I do grant that having children means that you have experimental test subjects whose environment you can control very well. But that's not what most people mean when they advocate "raising children" and there are moral concerns.
While I don't entirely agree with it, there is a common objection that needs to be addressed: the world is overpopulated. It may be the case that there are already too many new humans being created, and creating new humans causes more harm than help.
there is a common objection that needs to be addressed: the world is overpopulated
That seems to be just false.
The world is overpopulated in places like India, China, and especially the "third world". It's not overpopulated in the high infrastructure/education/social and economic capital centers like the US and Western Europe.
There's plenty of room for the people the children of the average LW reader are likely to become.
The rich countries are actually rather more overpopulated when you consider the sheer amount of resources we use - rather more than the poorer countries... a single person in a rich nation has many times the resource pull and footprint as one in a poor nation.
Overpopulation isn't a hard line. There's a continuum between 'having enough wealth to go around', and 'oh no, half the population is starving'. In between these two extremes, there are various stages of poverty. One of the first signs of overpopulation is unemployment i.e. too many people and not enough stuff for them to do. Most wealthy countries have comparatively low unemployment rate as of now, but history has shown that things can change swiftly. Just a doubling of the population of the USA would probably be more than enough to cause the unemployment rate to rise significantly.
One of the first signs of overpopulation is unemployment i.e. too many people and not enough stuff for them to do.
Third cause; This correlation does not imply causation.
This is only a valid symptom within certain preassumed conditions, and in other contexts fails horribly as a metric.
For illustration, a certain fictional island could have rather poor and difficult source of food (farmland, fish populations, etc.) that simply cannot sustain a population past X, regardless of whether the remaining (N-X) humans have work to do (infrastructure, repair, killing the Giant Death Crabs that prey on the farmers, etc.). Similarly, its sister island could have a large population of wild fruit-bearing trees that can freely sustain any number of humans up to Y, whether or not some of them find themselves without "work" or any skills valuable to other inhabitants.
Both of the above parables are related to real, but complex, issues with natural resource distribution and acquisition in the real world.
Overpopulation, by contrast, is when the net resources of a timespace / group / system can no longer reliably support the population by whatever metrics are necessary or employed by the population -- food, clothing, shelter, kinship, entertainment, and yes, even work, employment and unemployment.
But all of these depend on the context. If you fix the problem of humans requiring food, then food no longer needs to be considered as a metric for overpopulation. If you fix the problem of humans requiring employment to gain access to the food (which retains its own separate overpopulation threshold, generally held to be higher than employment in some places), then employment no longer needs to be considered as a metric for overpopulation.
I broadly agree with your point vis. the problem of requiring employment to gain access to food, but the real picture seems to be more complicated. In game-theoretic terms, once supply outpaces demand, demand often expands to fill available supply. If we can afford to provide food (or, more generally, energy and a small amount of material resources) to everyone simply by virtue of their existing, and we don't provide any controls over the level of population, it's only natural for population to balloon to fill up supply so that we again arrive at an equilibrium where we can't afford to feed everyone.
Broadly speaking, the argument for overpopulation is that population must be kept at a fixed level below the maximum carrying capacity of the environment, if everyone is to live comfortably.
it's only natural for population to balloon to fill up supply
Empirically, that does not seem to be happening in developed countries.
The world is overpopulated in places like India, China, and especially the "third world". It's not overpopulated in the high infrastructure/education/social and economic capital centers like the US and Western Europe.
There are plenty of people who want to migrate from the third world into the first. If you want more humans in the first world you can just allow migration.
There's no good way to filter immigration by cultural values. It's not just more humans in the first world, but more people with first-world values and education in the first world. (Yes, I think American/Western European/etc values are better than other places. If I didn't, I wouldn't have those kinds of values).
There's plenty of room in countries all over the world, if not in every individual community. We don't have a global overpopulation problem, we have a resource overconsumption problem, which, as CellBioGuy noted, is more concentrated in first world countries than third world.
The solution is not necessarily to reduce consumption, since many material limitations might be circumvented by technological means, but as it stands people in the first world still contribute more to the existing problem than people elsewhere.
Is there any good reason for having children you don't particularly want to have rather than (a) donating lots of high-quality gametes and (b) giving some or all of the money you would've spent on child-rearing to an organization that prevents the premature deaths of other children?
I never meant to argue that there was no way you could not have children and come out ahead in the moral calculus. Your suggestion, for example, might well work, yes. The market for donated gametes is limited - but not necessarily saturated, as David Gerard keeps pointing out. So contributing there may well do a lot of good on the margin.
It actually seems pretty difficult to see how having children would, on average, be anywhere near as strong an option if your outcome measures are (1) number of children who would otherwise would not exist/reach adulthood and (2) number of children produced using your (presumably much better than donor-average) genetic material.
There are a lot of factors that influence the cost to raise a child (e.g. family income, number of children in a single household), but the USDA's figures suggest that even a relatively low-income family ($0-60k combined household earnings) will be spending ~$175k per child. It's no question that you could redirect that money toward organizations that would save the lives of many children for less.
Gamete donation looks pretty good, too. If you're donating eggs, you probably won't produce many children - IVF success rates are still fairly low, and most donors only produce 10-15 eggs per cycle (although they can donate several times). On the other hand, screening tends to be a lot less discerning for egg donors compared to sperm donors - physical/hereditary health seems to be the primary concern. So if you're exceptionally intelligent, altruistic, and/or happy, it might be much better for your eggs to be put to use than the typical donor's. You can also net $5-15k per cycle, which you could donate toward saving even more children.
If you're donating sperm, you can potentially produce many more children than you could reasonably support as a caregiver (Cryos, apparently the world's largest sperm bank, claims that the "average donor" can expect to father 25 children), but due to slightly more stringent screening, the difference between the quality of your sperm and the average donor's might be a bit less stark. That said, most banks seem to care about things like education and height, which aren't necessarily great proxies for the things most of us care about.
So, assuming you're accepted as a donor and you actually follow through on donating a substantial amount of money, you can with near certainty cause many more children to reach adulthood than you could possibly raise and likely cause a few (or more) children to be born with your genes. All with a substantially lower time investment than you'd expect to sacrifice for child-rearing.
Instead of having children as a pseudo-solution to aging and death, wouldn't it make a lot more sense to work on solving those problems much more directly via research or earning-to-give to organizations doing research? From this perspective, having children is actually explicitly wasteful due to this clear opportunity cost of valuable time, money and effort, not to mention also very defeatist.
If you expect anti-aging technology to be so near that no more new humans at all are necessary for civilization to continue, then yes.
Adjusted for the rates of decline of human population if only a subset of the population ceases creating new humans and the time this gives us until we dip past the civilization-sustaining threshold, then yes, there exists a relatively large subset of humans where the equations balance out to the researchers having enough time to develop anti-aging technology before we reach the deadline.
How large is "large", and exactly how much time that represents, and which exact conditions define the subset of humans, are all yet to be determined (if I knew, I'd take over the world and make it happen!), but I'm rather confident that the number of such humans we could affort to put on Deathward duty is significantly higher than you've previously assumed.
(Partially leaning on the knowledge that human brains tend to fart out and underestimate severely when estimating the impact of large numbers like "6 billion", which you seem to have currently placed on the side where it would increase the number of quality-adjusted humans we produce and, thereby, the time we have until humanfall. )
If we're going this route, I'll make another pitch of my own!
Please work on whatever you think will improve society, and don't bother with new humans. By way of simple statistics, sheer numbers, base rates, and so on, the sheer amount of people out there making new humans means that, even if only 10% of them are as good as children that you would make, they'll still outdo whatever output you can give in Quality-Adjusted-New-Humans, and meanwhile all those people busy children-making would have diminishing returns and low value on other advances, while your very intelligent contributions are much more valuable.
Please, Obi-Wan Kenobi, you are our only hope!
By all means work on cool projects to improve society. You can do that even if you have children. It's a lot of work to raise a kid but it's not a life-destroying amount of work.
I cannot.
My time is limited by way of requiring to spend >50 hours / wk on a "self-sustainment" job, a restriction which would only be emboldened by the additional monetary requirements of human-making. The rest of my time can only be alotted to cool projects or human-making; I can not achieve both in sufficient quality to go past the treshold of a failed effort if my available time and resources are divided between the two. One or the other will fail, and probably both if I attempt a standard distribution of resources.
I suspect that many are in similar situations.
(Your point might still stand in a more general case; I've simply attempted to turn it from a discussion of arguments and options to a discussion about ratios of numbers of people matching categories of life situations.)
Hmm. Right. I have a job I feel is fulfilling and purposeful and this may certainly contribute to why we see this issue differently. If having children would make your life fall apart then I don't think you should.
We certainly agree that some people should have children and some people shouldn't and that this depends on a lot of factors. So in some sense, we just disagree about details. What I'm arguing for in particular is that highly effective people who have the ability and resources to provide children with a good home should have children. What seems to particularly rub people the wrong way is my suggestion that this is morally obligatory. While my views have not shifted greatly I've learned enough from this trainwreck of a post to argue this position less stridently next time around.
Agree with the rest, so not much further to add, except for:
What seems to particularly rub people the wrong way is my suggestion that this is morally obligatory. While my views have not shifted greatly I've learned enough from this trainwreck of a post to argue this position less stridently next time around.
Yes. The mostly-utilitarian environment around LW already doesn't support moral obligations, but on top of that due to the various issues surrounding moral systems it's frowned upon, partially due to the large risk of inducing conflict and confusion, to directly assert a claim like this that results from an assumed moral system.
Even though it seems like the majority of LW would "support" it, a post made entirely about encouraging people and justifying a case for the point that it should be morally obligatory for everyone to make expected utility calculations in a trolley problem and push down the fat man would not be that well received, I think.
An approach that, I think, would be much easier on this same subject with intellectual communities, particularly LessWrong, would be to claim that your point of argument (People X "should" have children!) contributes more towards some goal (Higher ratio of quality humans?) than alternatives, and is thus closer to optimal in that regards (if you claim something as truly optimal without any caveats and an extremely high probability, you damn well have the durasteel-solid math to prove it, or you deserve every criticism and tomato thrown your way! not that I'm guiltless of this myself).
EDIT: And to complete the last thougth above, which I thought I had written: And in most intellectual communities, the gap between "closer to optimal" and "moral obligation" is then easier to cross if one really wants to insist on this point. Arguments could be made that any sub-optimal is harm by opportunity costs, or about the relations of individuals' utility functions to social factors and thus to their behavior towards these "moral obligations", or various other ethics thinghies. Basically, it's just a more stable platform and a better meeting point for launching into a pitch on this subject.
This topic is in vogue, so here's my pitch.
My fellow humans, I have some bad news and some good news. The bad news is that you are likely to eventually enter an enfeebled state, during which you will not be able to independently provide for yourself. Even worse, you will at some point altogether cease to function and then you can no longer contribute to the things you care about. The good news is that both of those problems can be ameliorated by the same scheme – the creation of new humans. The new humans can provide us with the assistance we need as our own abilities diminish. And when we cease to function, the new humans can carry on with the projects we value.
Now, the thing is, creating fully functioning new humans is a huge project, consuming many man-years of work. A person engaged in preparing and outfitting a new human will need to sacrifice a lot of time that could otherwise be devoted to personal leisure and other projects. We currently have a volunteer system for replenishing the population and in many ways this works well. Not everyone is well-placed for creating humans while some people are in a good position to create many. But this system is not perfect and it can be exploited. There are some freeloaders who do not create humans even though they are in a suitable position to do so. Those same people almost always value receiving care in old age and value humanity having a future. But they are relying on the rest of us to provide enough new humans for this to happen while they can devote all their time to other projects and zero time to diapers with poop in them.
Sometimes the non-child-creators justify their decision by suggesting that the projects they are working on are especially socially valuable and thus they can spend time on them in preference to child-creation without violating their duty to society. While it is *possible* that this argument goes through in some cases, it seems suspiciously self-serving. What is especially worth taking into account is that if the humans in question really are so highly valuable, they would statistically have highly valuable offspring. Thus, it seems doubtful in the general case that high-value people refraining from procreating is a net gain for society.
[Poorly conceived section on my personal experiences removed.]