There are other government policies which are de facto birth control such as car seat laws, easy calling of CPS, and high safety standards around children generally which make kids more expensive in money and time
I agree these policies make kids more expensive but I am skeptical they enter significantly into the equation when people are considering whether to have kids or to avoid having kids.
I have no data, but it seems eminently logical to me. Expense always matters. If the family has a two bedroom apartment or house, and moving to a three bedroom home would be expensive, that's got to weigh on their minds. If they'd have to buy a new and bigger car, that must be relevant too.
If you avoided having kids because of these types of expenses, that would be some data. I know nobody who avoided having kids for reasons of expense, but do know lots of people (including my wife and I) who had kids in spite of those things.
Of the people I know who avoided having kids (including my wife and I deciding not to have a fourth kid), reasons were typically things like “don’t want to have to care for a newborn now that we’ve reached our mid-30s—all that hard work and lack of sleep is behind us” or “our family feels ‘complete’” or “after 3 c-sections it would be inadvisable” etc.
Some of my friends have avoided having ANY kids for the more conventional reasons like “i don’t feel ready” or the related “I need to get my career underway first”, or in one case “i don’t want to bring a kid into this world with things being the way they are in general”. I suspect there are also a few cases of “i don’t want to give up my fun carefree lifestyle”.
I think putting it as "did X because of reason Y" is usually a mistake. There are some people who were barely willing to have another kid, only barely willing because of costs A,B, and C, and adding cost X shifted "barely willing" to "not quite willing."
That's fair but what we are saying is we don't think it's even statistically significant. Have you honestly met a single person in your life that was like "sorry hun, let's abort kid number 4 because I don't want to buy another car seat".
I definitely never have and I've worked on homeless shelters where usually around 40% the clients were pregnant and many of whom gotten so even at the shelter, many with a half dozen kids already.
Generally in my albeit limited experience, abortions are driven mostly by spite and vanity. And decisions on numbers of kids just seems to a personal gut feeling between 2 and 5 depending on the mix of genders and some accidents too. A lot of people keep trying until they have one of each even if it takes five or six of them.
My family had 4 kids with a small barely 6 seat sedan. It was fun being sardined in. A similar car without the special triple baby seat can only fit two kids now
"In most past societies, the main career of most women was bearing and rearing children and running a household. One reason was that, with premodern mortality rates, maintaining a country’s population required something close to nonstop child bearing." - I don't think women gave much thought to maintaining the country's population in past societies when deciding whether to risk pregnancy. Rather, the high birth rates were more likely a result of social norms, lack of birth control, and a desire of the parents to have children who could look after them in old age in the absence of pension schemes and social services.
I agree that their motives were self-interested, but in order to have children to look after them a couple had to roughly reproduce themselves.
There is also Malthus' argument that, in a premodern society where the main resource was land, decreasing population leads to increasing income which leads to an increasing birth rate and reduction in child mortality, hence increasing population. That implies that the equilibrium population just reproduces itself.
It was a very clever idea. Malthus had the misfortune to come up with it just as it was becoming no longer true.
There is a second way Malthus can apply. As people in a wealthy country reduce its population by underbreeding, while people in nearby poor countries do the opposite, there's going to be pressure, both political and economic, for people in the poorer country to invade the richer one, whether as individual migrants, a mob, or an army. Eventually the rich country gets overwhelmed and conquered, and the world's civilized countries get de-gentrified into the third world. This is really happening, though it's debatable whether various state interventions aimed at preventing it would be justified. I expect that religion can do a better job anyway.
The US had massive immigration from poorer countries in the years before and after WWI. I don't think it got overwhelmed and conquered or degentrified.
Europe's immigration problems are largely due to the countries being welfare states, hence attracting the wrong kind of immigrants.
I think your second paragraph misses both the realities that a) most of Europe is not and has never been a melting pot like America still is, and b) that large scale Muslim immigration - perhaps partly because of the idea of Shariya law, though how much I do not claim to know - is very different from most of the other migration of poorer people to western democracies.
Part of the US migration was Eastern European Jews who, like modern Muslims, had their own legal system. Part was Italian and Irish Catholics, who had a different religion and one that many American Protestants viewed with alarm. How is Sharia different?
I agree that much of Europe consists of countries more nearly culturally homogenious than the US, although there were substantial Jewish or Romani minorities in some.
I'm a post-fertile female who never married and never bred.
I never wanted to be any child's primary caretaker, partly because the tasks and working conditions are extremely unattractive to me, partly because in my environment folks with that job got little respect, and partly because it both paid badly and was insecure - there was a high (perceived) risk of being dumped by their father, without the skills to support oneself, which had atrophied while raising his/your kids.
I don't regret that I was never able to arrange a situation where someone else would be a reliable primary care taker for my children, and so never had any. Sure, it might have been nice to have (grown) children with shared genetics, and family living situations can be great. But not at the cost of me being the stuckee for childrearing.
This personal experience colors my response to this issue. Other women's mileage may vary on the subject of the attractiveness of the tasks and working conditions. They may also perceive less risk of Mr. Right becoming a Deadbeat Ex. Perhaps they have the social skills to identify, attract and retain a better grade of prospects than I found available - or at least believe they do. And perhaps they lack skills and talents for some of the notably better paying and more respected alternative careers I found available to me.
But bottom line: you won't get people in my position breeding voluntarily, as long as it comes with primary caretaker responsibilities, or even a significant risk of them.
I don't know what proportion of American women of child rearing age share my preferences, either as absolutes or simply on balance compared to the alternatives they see. I suspect the proportion is not in fact as negligible as pro-natalists tend to expect.
At this point I also lack much of a sex drive, so can't really put myself in the emotional position of someone who's willing to risk conception in order to get laid, particularly in an environment where contraception and abortion are made unavailable. But I imagine women exist who fit that description - possibly quite a number of women, who we aren't seeing in the statistics because they use contraceptives routinely, backed up with legal abortion.
Banning those might get you more women with children they don't want to rear, and possibly resent more than love, doing the bare minimum to keep themselves out of jail, if they can't arrange to give up the child for adoption.
I don't think that's a great policy idea, but it might well appeal to parts of the political right.
Leaving that out, the question is how to make the job of primary caretaker attractive to people who don't like it, whether male or female. I have no idea, except that the more children and even young adults are culturally infantalized, aka constantly supervised at ages when I was going to local parks and swimming pools alone, the bigger the workload and the longer it lasts. That's presumably a negative for anyone who doesn't actively like that kind of work.
Good luck with that: I think you'll need it.
Meanwhile, there's the almost as difficult prospect of making child rearing affordable for more of the population, ideally earlier in their reproductive lifespans. I don't see that happening any time soon in the United States.
The issue of children being constantly supervised and of rearing being affordable are linked. People seventy or eighty years ago were poorer than we are, not richer, yet they managed to afford the cost of rearing children.
In my experience, people say they cannot afford a child -- and by afford they mean that a child should have good education (very expensive), good vacations, generally a decent lifestyle.
I don't think the least expensive good education is very expensive, although the most prestigious ones may be. There is an awful lot of free information available in books and online. People can have a decent lifestyle without being rich, unless the definition of decent lifestyle is such that almost nobody in the past had one.
Literally no-one in the past had a decent lifestyle by today’s standards. I wouldn’t want to be thrown back centuries into the past, even if I could be rich and powerful in that era.
Declining since before 1800, plummeted hard in the great depression, picked back up in WW2 then peaked in 1960, then declines again, then stabilizes more or less.
The story can be simplified to one of general decline with a single notable baby boom. While it would be parsimonious for a single explanation to explain the general trend of decline, I don't know that it should be expected to explain that exception (or that it needs to).
Notably, the general trend of decline continues, especially in the period after the end of your graph. Provisional data for 2024 indicate a TFR of 1.625: https://www.cdc.gov/nchs/data/vsrr/vsrr038.pdf.
The fertility drop will have to slow down, since it can't go below 0, but surprisingly, it hasn't really slowed down. Looking at the whole period in your graph, starting when TFR was over 7, TFR dropped by 0.024 per year. But in recent years, it's been falling even faster than that, falling by 0.031 per year over the last 14 years, and 0.038 over the last 4 years.
I had the same thoughts just from his marriage chart of 1890. I had wrote "I'll write more on this later but from the graphs you present, one thing that undermines the sky is falling, is things like kids, marriage rates, etc. don't seem that far off from lets say 1890 so curious TFR back then or was it mostly generated by mass European immigration to the US? I'd wager the number one TFR hold up in modern times is simply birth control (including abortion) though with Gen Z and Alpha seemingly to be adopting cultural homosexuality and Japanese anti-sex values so that might be changing too. As you said, people used to like sex and sex tends to lead to children regardless of marriage rates, etc." but then I got to your comment and you said it better and with a graph so I deleted and moved it here lol.
That said, I'd love to see that graphed against "average amount of sex" (not partners, actual sex) though I get that data doesn't exist, nobody even captures it today. It always blows my mind even today they capture "total lifetime partners" and not "total amount of sex". I know people that have had hundreds of partners before they died in their eighties and still had less sex than many long time married couples of fifty years I know. Increased sex makes babies, not increased partners.
“One conservative of my acquaintance argues that conservatives have higher birth rates than liberals, looks forward to a future when his opponents have bred themselves out of existence.”
The main problem with this forward look is that it is leftists (most of them are no longer “liberal”) who run the indoctrination facilities that are the public school system, so they will be able to “bleed off” plenty of the children of conservatives and pull them into the leftist fold as long as that situation continues.
You're willing to tax punish two income households, "perhaps by changes in tax law that disfavor two income households." and sticks work as well as carrots for incentives.
Why not go further and increase SS taxes on childless adults? If, after age 40, an adult has no kids, their employer pays 2x the SS contribution.
Having the kids of parents who raised them pay more in SS for those too selfish/ individualistic oriented to get married & raise kids seems more unfair than increasing the SS taxes on those who will likely need more state care in their old age.
If old age care is the biggest financial issue of lower fertility.
Which might well not happen if AI & robots can effectively treat the old as did Moorlocks treat the Eloi in The Time Machine.
Bryan Caplan points out that there is likely an extremely effective government policy to raise fertility at much less than zero cost. He didn’t put it quite this way, but simply end government aid for college and university education in the arts, humanities, and social sciences.
It is well-established that the strongest (negative) predictor of fertility is women’s average educational level. And that in turn tracks (negatively) the cost of that education in the fields women want to pursue, *supra*, which by the way are (probably) the ones with negative externalities. (Even most *economists* are illibertarian, as I’m sure I needn’t tell you, Prof. Friedman.)
(In fact Caplan’s own proposal is still more radical: Bryan Caplan, The Case Against Education: Why the Education System Is a Waste of Time and Money, 2018, Princeton University Press.)
It strikes me as a fallacy to assign a single best interest to a person over his lifetime. It may be that the twenty year old accurately assesses his future self's interest but doesn't provide it adequate weight. Or it may be that he doesn't plan that far in advance. Ask your students how far ahead they think.
You live in the United States, which has a low population density, 37/km², placing 183rd on Wikipedia’s list of 245 countries and dependencies. I live in Spain, which has 97/km², and that’s low by European standards. I come from England, which has 450/km². The world as I see it is overpopulated, I dislike crowds and cities, and to me falling population is good news. Yes, it may come with some associated problems, but countries should be capable of coping with them.
The more people we have on the planet, the more we damage the environment we live in.
Humanity is in no danger of dying out for lack of people. There are currently some 8,300,000,000 humans running around; in 1900, there were only about 1,600,000,000, and further back much fewer.
People tend to badly overestimate how crowded the world is because they see mostly the places where there are people. They are implicitly judging by how densely populated the the location is where the average person lives, averaging density over people instead of over acres. The reason for the uneven pattern of density is that most people find the advantages of a dense population to be greater than the disadvantages so choose to live where there are lots of other people.
If you dislike crowds and cities you can, perhaps do, choose to live somewhere far from a city or a crowd.
At least a quarter of the global net primary productivity (i.e energy captured and carbon fixed in photosynthesis) is captured by people along with livestock.
Nitrogen cycle is dominated by man-made fixation of nitrogen.
Energy employed to move earth exceeds geotectonic energy
India who is now embarking on orgy of road building will soon have no corner left undeveloped.
Oh, I do avoid cities. But when I go on holiday I also have to avoid the best-known places because they’re ruined by crowds of other tourists.
Of course, my personal preferences aren’t really important, compared with the damage done to the planet by the excessive number of humans on it.
People tend to gather in cities not because they love cities (though some do, oddly enough) but because they need jobs, which tend to be found in cities. I’m lucky there, I can work at home by Internet, I don’t need to live in a city. I hope that more and more people will enjoy this advantage in future.
1. Jobs being an advantage of dense populations is a pre-Internet phenomenon (although it is taking time to die out).
2. I don’t know either what the ideal number of humans on this planet would be. It’s a subjective matter; different numbers would be ideal for different people. For me, the present number is excessive, so I’d be happy to see it fall.
3. Damage may be defined as a change that you dislike. Thus, it’s also subjective. Some changes are described as ‘pollution’ and are disliked by most people.
How confident are you that the net effect on the planet of more people is by your standards negative? One effect is greening the planet, increasing the total amount of vegetation. Arguably the first big change, population increase due to the discovery of agriculture, is the reason the next glaciation isn't starting (the Early Anthropogenic Hypothesis). Most other effects are in places you have never seen, making it difficult to evaluate them.
You are of course right that changes in population, up or down, can have non-obvious side effects, so I can’t be sure that I’d prefer to live in a world with a much lower population. If I had the power to wave a wand and magically decrease world population (that sounds better than “kill or vanish lots of people”), I should first think carefully and research the subject. As I have no such power, I don’t need to be so sure about it. I can merely say that the thought of a declining world population doesn’t bother me.
I point out that an increased world population takes us into the unknown: we’ve never had a world population greater than it is now. Whereas a decreased world population has already been tried: however low the population gets, it has been tried before sometime in history, with tolerable results.
Barring catastrophe, world population is projected to go on increasing until after I’m dead, so I’m not actually likely to experience a fall in population. The population of Spain, where I live, is also increasing, though mostly through immigration.
“The more people we have on the planet, the more we damage the environment we live in.”
But in fact the richer societies become, the less damage gets done to the environment.
I strongly suggest you read “Fossil Future” to understand the implicit Mother Gaia worship religious faith that your statement makes clear you have bought into.
Or perhaps you have bought into it explicitly, idk.
Nothing to do with any religion; it’s an obvious fact of life. People damage the environment; the more people, the more damage. If you cannot see the obvious, that’s your problem. Would you claim that I was suffering from religious belief if I asserted that 2 + 2 = 4?
"People damage the environment; the more people, the more damage. If you cannot see the obvious, that’s your problem."
That may well be true in Subsharan Africa and in North Korea. And in the U.S. 100+ years ago.
But if you can't see that as people have gotten wealthier, they have done less damage to the environment, and in the rich western world the environment is *less* damaged rather than more damaged now than it was 75 and 50 years ago, despite there being a greater number of people in those countries, that's your problem.
Because the historical evidence is overwhelming.
As Daniel Patrick Moynihan famously said, you are entitled to your own opinions, but not your own facts.
Population and wealth are separate variables. Whether wealthier people do less damage per person is a matter of opinion, not fact. It seems to me that they do less of some kinds of damage, but more of other kinds of damage. Regardless, for any given level of wealth, more people do more damage.
Of course, the simple way of coping would be to reduce those benefits, but governments can decide for themselves what to do about it. Balancing their accounts is their job, not mine. My point is that a declining population is not an existential threat to humanity, unless it goes on declining to zero, which is hardly likely. At some point, the population will either stabilize or start to increase again.
No one in this thread ever claimed a declining population was an existential threat (except, of course, at the extreme).
I said that declining population has significant downsides. And in particular very significant downsides for middle class and poor people who live in rich countries today and hope for improved lives, and at minimum expect not to have significantly materially worse off lives.
Declining population in rich countries as a practical matter in fact increases the chances that people will be worse off. The fact that governments (elected by people) *could* do something else with their old age redistribution policies notwithstanding.
In general, any change is likely to have some good effects and some bad effects, and changes that affect whole countries are likely to be good for some people and bad for others. Even catastrophes may happen to benefit a small minority of people.
A declining population will probably have a bad effect on some people, like any other significant change in country status. An increasing population will probably have a bad effect on other people. Who knows, there may be people who would be badly affected in different ways by both a declining and an increasing population.
I feel relatively cheerful about the prospect of declining populations, I’d prefer to live in a less crowded world (during my lifetime, world population has roughly tripled). But don’t blame me for any bad effects: I’m not responsible for these phenomena. I’m just an observer.
Question for the gallery as I was talking to my daughter about this and it struck me, I've never once* heard a female "thinker" voice on this everyl, it's always men though maybe I'm just in a bubble. Anyone aware of any*?
* Ignoring misandrists. Yes yes yes I've heard a few voices on this that blame men for not being better (zero sum game hence discountable), waking up to intersectionality, feminism voices about freeing themselves from oppression and a hostility to humanity even existing period, etc and not interested in more of those. Everything in my circles guys write about effect women equally, it's not a gendered issue, hence there should be some women's voices on this somewhere with the same worries.
Does a decline in population CREATE problems? Yes -- every change comes with various challenges because, well, it's change. The main one I hear is the "fewer active workers to support more retirees" ... but unless life extension advances outpace birth rate declines, that's a temporary problem.
Does a decline in population CONSTITUTE a problem in and of itself? I see no reason why it should. "Too much" population growth can strain existing resource availability, but automation seems to have reached a point where population reduction won't mean there aren't enough people to e.g. mine the coal or farm the cattle or maintain the spreadsheets.
And to me, the spreadsheets is what it really comes down to. Specifically, the bureaucrats' spreadsheets and them not wanting their grandiose plans for the future of society disrupted by the messy business of people deciding for themselves whether they want to have 1.2 kids or 0.8 kids.
If population continues to decline, as it will if TFR remains below replacement, each generation will be smaller than the last so the problem, if it exists, is permanent even with no advances in life extension.
There are a number of variables involved other than TFR. Does lifespan increase, decrease, or stay the same? Is the average working life still 42-46 years, or is it longer or shorter? Have the automation/scarcity variables changed drastically or remained within a similar range to now?
I'm not a supporter of "Universal Basic Income," but if automation, AI, etc. continue to increase productivity and reduce scarcity levels, I suspect things will go in that direction.
We'll never not have problems, but I don't see population decline as inherently problematic.
Absent an AI mega productivity boom, the problem is that our old age entitlements become a Ponzi scheme absent an ever increasing economy, which requires an increasing workforce.
In the US, the Social Security entitlement is already a Ponzi scheme. The size of the "new investor" class (workers paying Social Security taxes) continues to decline relative to the population of "investors receiving the promised profits" (retirees). And an ever increasing economy can't inherently save it as it's currently structured, since Cost of Living Adjustments track inflation/CPI.
There are going to be changes to that entitlement, because there's no other choice than to change it, even if the change means just letting it collapse.
In my view, the LEAST likely change to it is a big Baby Boom that changes the worker-to-retiree ratio to keep it limping along. The only likely way to achieve that would be to send soldiers around forcing young couples to make the beast with two backs until the pregnancy tests come back positive, and then watch over them until the babies are delivered. Ceausescu found out how well that kind of approach goes over.
Absolutely. And the most likely course to ever-increasing productivity is, IMO, more and more productive robots, etc. replacing fewer (or at least not ever-increasing) less productive humans in the production of goods and delivery of services.
I don't think that, as such, is really a utopian prediction. The first part of it is essentially the history of humanity since at least the beginning of the Industrial Revolution, and reduced population won't be all good times and noodle salad even if we find a non-dystopian way past the intermediate "nobody has a job anymore, which means nobody is getting paid, which means everyone starves" concerns.
“And an ever increasing economy can't inherently save it as it's currently structured, since Cost of Living Adjustments track inflation/CPI.”
This claim is simply untrue, and you have neither facts nor math that can back it up.
Further, the fact that the benefits are CPI-adjusted ain’t really a big problem. The fact that benefits grow until retirement with average earnings, not merely with CPI, is a huge part of the problem. Change that one thing and you would address almost 80% of the current SS shortfall.
I tend to think that the explanation is mostly technological change: better birth control. But there are a few things I think governments do that probably lower TFR: (1) sex education teaches kids how to use birth control and urges them to do so, (2) subsidizing birth control & (3) keeping teens locked up in school all day probably causes them to have less sex than they would if they had more free time while their parents are at work.
I think there has been some relevant technological change in that period as well, but I agree that the theory needs some epicycles. And https://www.statista.com/chart/30907/contraceptive-use-by-type/ shows that there are large cultural differences in the choice of contraceptive method, which presumably has some effect on TFR. I'd also expect cultures that prefer short-acting methods to experience stronger selection for genes that increase the likelihood of accidental pregnancy.
John Brunner’s Stand on Zanzibar, or not. Prophetic or pathetic much he saw we are.
I'd written four more paragraphs here starting from his theme, but noticed they pretty much led to and mirrored your last paragraph, hence I deleted them, oh well.
David, is your conservative friend aware that children of conservative parents may (and frequently enough, do) grow up to decide they are not conservative themselves? And that even if the children carry on in their parents’ footsteps by identifying as conservative when they grow up, many of the actual views they hold may be wildly un-conservative by their parents’ standards? In fact, even the parents’ own conservative beliefs have likely undergone changes, so that by calling themselves conservatives in their 20s and retaining this identity label in their 60s they will have caused the term “conservative” to change its meaning.
(Of course the truth is that “conservative” in the sense of “approach changes with caution and err on the side of keeping things as they are” has nothing to do with “politically conservative”, which can be more accurately summarized as “oppose whatever is associated with political liberals”. Thus the ideological implications of the two political terms change constantly and contain practically no information as far as what kinds of fundamental values drive people’s behaviors and beliefs.)
I recall seeing studies to that effect, but I also recall seeing the metric being something like “if your parents voted Republican you will be more likely to vote Republican” etc. I am pointing out that (1) it certainly isn’t a foregone conclusion (for instance a black swan event or momentous cultural shift can drive a lot of people to the other side, as has happened numerous times), and (2) this metric is nonsense in a world where “Republican” can have completely different policy connotations from one decade to the next. (Did your friend say this before or after Trump’s election, I wonder?)
What’s really getting passed on are personality traits, which by doing a lot of hand waving we can map to one political ideology or another—temporarily. I think it would be truer and more elegant to say something like “intelligent, virtuous people should have more kids, to increase the proportion of such people in the future.” To put it the way your friend did strikes me as a sort of empty grandstanding, which I think is why I bristled at it.
I think his view is that the left/right split is driven by underlying personality characteristics, probably genetic. My Substack (and others) is mirrored to the forum where we interact, so he may offer his own views.
How different were other characteristics of your personality? It might be a case where two very different political positions were both consistent with the same underlying attitudes. Ex-communists sometimes become committed conservatives, and socialist George Orwell feels, from his letters and essays, like my kind of person.
I am probably more contrarian and fiercely individualistic than my twin is, but if I discount the different paths our lives took and the different sorts of social worlds we consequently inhabited and what we absorbed from them, he and I have quite similar personalities in many ways. It's probably exposure to those different worlds that led to our divergent politics.
Of course there's a sorta deterministic argument to be made that our lives took different paths because of our different personalities, but there I could probably point to different social influences during adolescence that caused our paths to split (during our formative years and into adulthood). But then a determinist like Robert Sapolsky might say it was personality differences that led us to those different social influences, and maybe this would go back and forth until he's claiming that when our zygote split one of us got a slightly different hormone cocktail than the other one.
Either way, what we'd then be talking about is hormones and personality, not politics, and I think we'd have conclusively shown that politics are beside the point.
Is your friend claiming that there are certain combinations of opposing political views that are compatible with the same personality, and that these are only an edge case and do not invalidate his ideas about parents passing their politics on to their children?
There are other government policies which are de facto birth control such as car seat laws, easy calling of CPS, and high safety standards around children generally which make kids more expensive in money and time
I agree these policies make kids more expensive but I am skeptical they enter significantly into the equation when people are considering whether to have kids or to avoid having kids.
I have no data, but it seems eminently logical to me. Expense always matters. If the family has a two bedroom apartment or house, and moving to a three bedroom home would be expensive, that's got to weigh on their minds. If they'd have to buy a new and bigger car, that must be relevant too.
If you avoided having kids because of these types of expenses, that would be some data. I know nobody who avoided having kids for reasons of expense, but do know lots of people (including my wife and I) who had kids in spite of those things.
Of the people I know who avoided having kids (including my wife and I deciding not to have a fourth kid), reasons were typically things like “don’t want to have to care for a newborn now that we’ve reached our mid-30s—all that hard work and lack of sleep is behind us” or “our family feels ‘complete’” or “after 3 c-sections it would be inadvisable” etc.
Some of my friends have avoided having ANY kids for the more conventional reasons like “i don’t feel ready” or the related “I need to get my career underway first”, or in one case “i don’t want to bring a kid into this world with things being the way they are in general”. I suspect there are also a few cases of “i don’t want to give up my fun carefree lifestyle”.
I think putting it as "did X because of reason Y" is usually a mistake. There are some people who were barely willing to have another kid, only barely willing because of costs A,B, and C, and adding cost X shifted "barely willing" to "not quite willing."
True of a lot of things in a multicausal world.
I think you are overestimating how many pregnancies are planned.
I think you have no more data than I do, and it doesn't matter, because it must have some effect, and that is all that I am claiming.
I didn’t say there was no effect, i said i was skeptical that the effect is significant. So we agree!
That's fair but what we are saying is we don't think it's even statistically significant. Have you honestly met a single person in your life that was like "sorry hun, let's abort kid number 4 because I don't want to buy another car seat".
I definitely never have and I've worked on homeless shelters where usually around 40% the clients were pregnant and many of whom gotten so even at the shelter, many with a half dozen kids already.
Generally in my albeit limited experience, abortions are driven mostly by spite and vanity. And decisions on numbers of kids just seems to a personal gut feeling between 2 and 5 depending on the mix of genders and some accidents too. A lot of people keep trying until they have one of each even if it takes five or six of them.
Have you honestly met a single person in your life who would tell you such intimate details?
No need to be skeptical, there are decent papers on this
https://www.journals.uchicago.edu/doi/10.1086/731812
Paywalled so I can’t see their methodology, how they addressed possible confounds, and how they show causality.
Older version of the paper here: https://assets.super.so/6b4b5d92-904a-4e7b-95bd-914dd1d1528f/files/731b077f-0094-48a2-9414-a45a9a655456.pdf discussed here: https://www.lesswrong.com/posts/c4daDbQD398BmW5k5/on-car-seats-as-contraception.
My family had 4 kids with a small barely 6 seat sedan. It was fun being sardined in. A similar car without the special triple baby seat can only fit two kids now
"In most past societies, the main career of most women was bearing and rearing children and running a household. One reason was that, with premodern mortality rates, maintaining a country’s population required something close to nonstop child bearing." - I don't think women gave much thought to maintaining the country's population in past societies when deciding whether to risk pregnancy. Rather, the high birth rates were more likely a result of social norms, lack of birth control, and a desire of the parents to have children who could look after them in old age in the absence of pension schemes and social services.
I agree that their motives were self-interested, but in order to have children to look after them a couple had to roughly reproduce themselves.
There is also Malthus' argument that, in a premodern society where the main resource was land, decreasing population leads to increasing income which leads to an increasing birth rate and reduction in child mortality, hence increasing population. That implies that the equilibrium population just reproduces itself.
It was a very clever idea. Malthus had the misfortune to come up with it just as it was becoming no longer true.
There is a second way Malthus can apply. As people in a wealthy country reduce its population by underbreeding, while people in nearby poor countries do the opposite, there's going to be pressure, both political and economic, for people in the poorer country to invade the richer one, whether as individual migrants, a mob, or an army. Eventually the rich country gets overwhelmed and conquered, and the world's civilized countries get de-gentrified into the third world. This is really happening, though it's debatable whether various state interventions aimed at preventing it would be justified. I expect that religion can do a better job anyway.
The US had massive immigration from poorer countries in the years before and after WWI. I don't think it got overwhelmed and conquered or degentrified.
Europe's immigration problems are largely due to the countries being welfare states, hence attracting the wrong kind of immigrants.
I agree with your first paragraph.
I think your second paragraph misses both the realities that a) most of Europe is not and has never been a melting pot like America still is, and b) that large scale Muslim immigration - perhaps partly because of the idea of Shariya law, though how much I do not claim to know - is very different from most of the other migration of poorer people to western democracies.
Part of the US migration was Eastern European Jews who, like modern Muslims, had their own legal system. Part was Italian and Irish Catholics, who had a different religion and one that many American Protestants viewed with alarm. How is Sharia different?
I agree that much of Europe consists of countries more nearly culturally homogenious than the US, although there were substantial Jewish or Romani minorities in some.
I'm a post-fertile female who never married and never bred.
I never wanted to be any child's primary caretaker, partly because the tasks and working conditions are extremely unattractive to me, partly because in my environment folks with that job got little respect, and partly because it both paid badly and was insecure - there was a high (perceived) risk of being dumped by their father, without the skills to support oneself, which had atrophied while raising his/your kids.
I don't regret that I was never able to arrange a situation where someone else would be a reliable primary care taker for my children, and so never had any. Sure, it might have been nice to have (grown) children with shared genetics, and family living situations can be great. But not at the cost of me being the stuckee for childrearing.
This personal experience colors my response to this issue. Other women's mileage may vary on the subject of the attractiveness of the tasks and working conditions. They may also perceive less risk of Mr. Right becoming a Deadbeat Ex. Perhaps they have the social skills to identify, attract and retain a better grade of prospects than I found available - or at least believe they do. And perhaps they lack skills and talents for some of the notably better paying and more respected alternative careers I found available to me.
But bottom line: you won't get people in my position breeding voluntarily, as long as it comes with primary caretaker responsibilities, or even a significant risk of them.
I don't know what proportion of American women of child rearing age share my preferences, either as absolutes or simply on balance compared to the alternatives they see. I suspect the proportion is not in fact as negligible as pro-natalists tend to expect.
At this point I also lack much of a sex drive, so can't really put myself in the emotional position of someone who's willing to risk conception in order to get laid, particularly in an environment where contraception and abortion are made unavailable. But I imagine women exist who fit that description - possibly quite a number of women, who we aren't seeing in the statistics because they use contraceptives routinely, backed up with legal abortion.
Banning those might get you more women with children they don't want to rear, and possibly resent more than love, doing the bare minimum to keep themselves out of jail, if they can't arrange to give up the child for adoption.
I don't think that's a great policy idea, but it might well appeal to parts of the political right.
Leaving that out, the question is how to make the job of primary caretaker attractive to people who don't like it, whether male or female. I have no idea, except that the more children and even young adults are culturally infantalized, aka constantly supervised at ages when I was going to local parks and swimming pools alone, the bigger the workload and the longer it lasts. That's presumably a negative for anyone who doesn't actively like that kind of work.
Good luck with that: I think you'll need it.
Meanwhile, there's the almost as difficult prospect of making child rearing affordable for more of the population, ideally earlier in their reproductive lifespans. I don't see that happening any time soon in the United States.
The issue of children being constantly supervised and of rearing being affordable are linked. People seventy or eighty years ago were poorer than we are, not richer, yet they managed to afford the cost of rearing children.
Absolutely. I'm old enough to remember child rearing and prosperity as of 60 years ago, if not 70 or 80. And IIRC, you are older than I am.
I was born in 1945.
I think this is very valid.
In my experience, people say they cannot afford a child -- and by afford they mean that a child should have good education (very expensive), good vacations, generally a decent lifestyle.
It is a variant of "life worth living".
I don't think the least expensive good education is very expensive, although the most prestigious ones may be. There is an awful lot of free information available in books and online. People can have a decent lifestyle without being rich, unless the definition of decent lifestyle is such that almost nobody in the past had one.
Literally no-one in the past had a decent lifestyle by today’s standards. I wouldn’t want to be thrown back centuries into the past, even if I could be rich and powerful in that era.
I think any explanation needs to deal with the odd chart shape of fertility.
https://www.statista.com/statistics/1033027/fertility-rate-us-1800-2020/
Declining since before 1800, plummeted hard in the great depression, picked back up in WW2 then peaked in 1960, then declines again, then stabilizes more or less.
The story can be simplified to one of general decline with a single notable baby boom. While it would be parsimonious for a single explanation to explain the general trend of decline, I don't know that it should be expected to explain that exception (or that it needs to).
Notably, the general trend of decline continues, especially in the period after the end of your graph. Provisional data for 2024 indicate a TFR of 1.625: https://www.cdc.gov/nchs/data/vsrr/vsrr038.pdf.
The fertility drop will have to slow down, since it can't go below 0, but surprisingly, it hasn't really slowed down. Looking at the whole period in your graph, starting when TFR was over 7, TFR dropped by 0.024 per year. But in recent years, it's been falling even faster than that, falling by 0.031 per year over the last 14 years, and 0.038 over the last 4 years.
Globally, we see clear continued decline: https://ourworldindata.org/fertility-rate
EDIT: updated figures show even lower TFR in 2024, and a continued decline in 2025: https://xcancel.com/BirthGauge/status/2019465958927077680#m.
I had the same thoughts just from his marriage chart of 1890. I had wrote "I'll write more on this later but from the graphs you present, one thing that undermines the sky is falling, is things like kids, marriage rates, etc. don't seem that far off from lets say 1890 so curious TFR back then or was it mostly generated by mass European immigration to the US? I'd wager the number one TFR hold up in modern times is simply birth control (including abortion) though with Gen Z and Alpha seemingly to be adopting cultural homosexuality and Japanese anti-sex values so that might be changing too. As you said, people used to like sex and sex tends to lead to children regardless of marriage rates, etc." but then I got to your comment and you said it better and with a graph so I deleted and moved it here lol.
That said, I'd love to see that graphed against "average amount of sex" (not partners, actual sex) though I get that data doesn't exist, nobody even captures it today. It always blows my mind even today they capture "total lifetime partners" and not "total amount of sex". I know people that have had hundreds of partners before they died in their eighties and still had less sex than many long time married couples of fifty years I know. Increased sex makes babies, not increased partners.
“One conservative of my acquaintance argues that conservatives have higher birth rates than liberals, looks forward to a future when his opponents have bred themselves out of existence.”
The main problem with this forward look is that it is leftists (most of them are no longer “liberal”) who run the indoctrination facilities that are the public school system, so they will be able to “bleed off” plenty of the children of conservatives and pull them into the leftist fold as long as that situation continues.
You're willing to tax punish two income households, "perhaps by changes in tax law that disfavor two income households." and sticks work as well as carrots for incentives.
Why not go further and increase SS taxes on childless adults? If, after age 40, an adult has no kids, their employer pays 2x the SS contribution.
Having the kids of parents who raised them pay more in SS for those too selfish/ individualistic oriented to get married & raise kids seems more unfair than increasing the SS taxes on those who will likely need more state care in their old age.
If old age care is the biggest financial issue of lower fertility.
Which might well not happen if AI & robots can effectively treat the old as did Moorlocks treat the Eloi in The Time Machine.
Bryan Caplan points out that there is likely an extremely effective government policy to raise fertility at much less than zero cost. He didn’t put it quite this way, but simply end government aid for college and university education in the arts, humanities, and social sciences.
It is well-established that the strongest (negative) predictor of fertility is women’s average educational level. And that in turn tracks (negatively) the cost of that education in the fields women want to pursue, *supra*, which by the way are (probably) the ones with negative externalities. (Even most *economists* are illibertarian, as I’m sure I needn’t tell you, Prof. Friedman.)
(In fact Caplan’s own proposal is still more radical: Bryan Caplan, The Case Against Education: Why the Education System Is a Waste of Time and Money, 2018, Princeton University Press.)
It strikes me as a fallacy to assign a single best interest to a person over his lifetime. It may be that the twenty year old accurately assesses his future self's interest but doesn't provide it adequate weight. Or it may be that he doesn't plan that far in advance. Ask your students how far ahead they think.
You live in the United States, which has a low population density, 37/km², placing 183rd on Wikipedia’s list of 245 countries and dependencies. I live in Spain, which has 97/km², and that’s low by European standards. I come from England, which has 450/km². The world as I see it is overpopulated, I dislike crowds and cities, and to me falling population is good news. Yes, it may come with some associated problems, but countries should be capable of coping with them.
The more people we have on the planet, the more we damage the environment we live in.
Humanity is in no danger of dying out for lack of people. There are currently some 8,300,000,000 humans running around; in 1900, there were only about 1,600,000,000, and further back much fewer.
People tend to badly overestimate how crowded the world is because they see mostly the places where there are people. They are implicitly judging by how densely populated the the location is where the average person lives, averaging density over people instead of over acres. The reason for the uneven pattern of density is that most people find the advantages of a dense population to be greater than the disadvantages so choose to live where there are lots of other people.
If you dislike crowds and cities you can, perhaps do, choose to live somewhere far from a city or a crowd.
At least a quarter of the global net primary productivity (i.e energy captured and carbon fixed in photosynthesis) is captured by people along with livestock.
Nitrogen cycle is dominated by man-made fixation of nitrogen.
Energy employed to move earth exceeds geotectonic energy
India who is now embarking on orgy of road building will soon have no corner left undeveloped.
Oh, I do avoid cities. But when I go on holiday I also have to avoid the best-known places because they’re ruined by crowds of other tourists.
Of course, my personal preferences aren’t really important, compared with the damage done to the planet by the excessive number of humans on it.
People tend to gather in cities not because they love cities (though some do, oddly enough) but because they need jobs, which tend to be found in cities. I’m lucky there, I can work at home by Internet, I don’t need to live in a city. I hope that more and more people will enjoy this advantage in future.
The fact that jobs are found in cities is not a random factoid, it is a consequence of advantages of dense populations.
I don't know what an "excessive number" of humans is. What would be the right number? Why?
The existence of humans changes the surface of the planet in various ways. What makes some changes damage, beyond your not liking them?
1. Jobs being an advantage of dense populations is a pre-Internet phenomenon (although it is taking time to die out).
2. I don’t know either what the ideal number of humans on this planet would be. It’s a subjective matter; different numbers would be ideal for different people. For me, the present number is excessive, so I’d be happy to see it fall.
3. Damage may be defined as a change that you dislike. Thus, it’s also subjective. Some changes are described as ‘pollution’ and are disliked by most people.
How confident are you that the net effect on the planet of more people is by your standards negative? One effect is greening the planet, increasing the total amount of vegetation. Arguably the first big change, population increase due to the discovery of agriculture, is the reason the next glaciation isn't starting (the Early Anthropogenic Hypothesis). Most other effects are in places you have never seen, making it difficult to evaluate them.
I was born in 1954, at which time the world population was a third of what it is now. For every human on the planet then, we now have three!
You are of course right that changes in population, up or down, can have non-obvious side effects, so I can’t be sure that I’d prefer to live in a world with a much lower population. If I had the power to wave a wand and magically decrease world population (that sounds better than “kill or vanish lots of people”), I should first think carefully and research the subject. As I have no such power, I don’t need to be so sure about it. I can merely say that the thought of a declining world population doesn’t bother me.
I point out that an increased world population takes us into the unknown: we’ve never had a world population greater than it is now. Whereas a decreased world population has already been tried: however low the population gets, it has been tried before sometime in history, with tolerable results.
Barring catastrophe, world population is projected to go on increasing until after I’m dead, so I’m not actually likely to experience a fall in population. The population of Spain, where I live, is also increasing, though mostly through immigration.
The more people we have, the more innovation they bring to the table.
And some innovations may wreck us like innovation of Karl Marx.
Only when government gets involved. Government coercion is the root of 99% of problems.
C’mon - you cannot be confident it’s the root of more than ~92% of problems, can you? 😏
Don’t worry. Al-Andalus will soon shed much of its infidel population.
“The more people we have on the planet, the more we damage the environment we live in.”
But in fact the richer societies become, the less damage gets done to the environment.
I strongly suggest you read “Fossil Future” to understand the implicit Mother Gaia worship religious faith that your statement makes clear you have bought into.
Or perhaps you have bought into it explicitly, idk.
I’ve never had any religion. I just disagree with you.
“I’ve never had any religion.”
Your assertion that more people on the planet means more damage to the environment begs to differ…
Nothing to do with any religion; it’s an obvious fact of life. People damage the environment; the more people, the more damage. If you cannot see the obvious, that’s your problem. Would you claim that I was suffering from religious belief if I asserted that 2 + 2 = 4?
"People damage the environment; the more people, the more damage. If you cannot see the obvious, that’s your problem."
That may well be true in Subsharan Africa and in North Korea. And in the U.S. 100+ years ago.
But if you can't see that as people have gotten wealthier, they have done less damage to the environment, and in the rich western world the environment is *less* damaged rather than more damaged now than it was 75 and 50 years ago, despite there being a greater number of people in those countries, that's your problem.
Because the historical evidence is overwhelming.
As Daniel Patrick Moynihan famously said, you are entitled to your own opinions, but not your own facts.
Population and wealth are separate variables. Whether wealthier people do less damage per person is a matter of opinion, not fact. It seems to me that they do less of some kinds of damage, but more of other kinds of damage. Regardless, for any given level of wealth, more people do more damage.
“Yes, it may come with some associated problems, but countries should be capable of coping with them.”
Absent overly generous old age welfare benefits in all developed countries, you would probably be correct.
But the Ponzi nature of those benefits means those countries are in big trouble absent ever growing economies.
Of course, the simple way of coping would be to reduce those benefits, but governments can decide for themselves what to do about it. Balancing their accounts is their job, not mine. My point is that a declining population is not an existential threat to humanity, unless it goes on declining to zero, which is hardly likely. At some point, the population will either stabilize or start to increase again.
No one in this thread ever claimed a declining population was an existential threat (except, of course, at the extreme).
I said that declining population has significant downsides. And in particular very significant downsides for middle class and poor people who live in rich countries today and hope for improved lives, and at minimum expect not to have significantly materially worse off lives.
Declining population in rich countries as a practical matter in fact increases the chances that people will be worse off. The fact that governments (elected by people) *could* do something else with their old age redistribution policies notwithstanding.
In general, any change is likely to have some good effects and some bad effects, and changes that affect whole countries are likely to be good for some people and bad for others. Even catastrophes may happen to benefit a small minority of people.
A declining population will probably have a bad effect on some people, like any other significant change in country status. An increasing population will probably have a bad effect on other people. Who knows, there may be people who would be badly affected in different ways by both a declining and an increasing population.
I feel relatively cheerful about the prospect of declining populations, I’d prefer to live in a less crowded world (during my lifetime, world population has roughly tripled). But don’t blame me for any bad effects: I’m not responsible for these phenomena. I’m just an observer.
Question for the gallery as I was talking to my daughter about this and it struck me, I've never once* heard a female "thinker" voice on this everyl, it's always men though maybe I'm just in a bubble. Anyone aware of any*?
* Ignoring misandrists. Yes yes yes I've heard a few voices on this that blame men for not being better (zero sum game hence discountable), waking up to intersectionality, feminism voices about freeing themselves from oppression and a hostility to humanity even existing period, etc and not interested in more of those. Everything in my circles guys write about effect women equally, it's not a gendered issue, hence there should be some women's voices on this somewhere with the same worries.
Does a decline in population CREATE problems? Yes -- every change comes with various challenges because, well, it's change. The main one I hear is the "fewer active workers to support more retirees" ... but unless life extension advances outpace birth rate declines, that's a temporary problem.
Does a decline in population CONSTITUTE a problem in and of itself? I see no reason why it should. "Too much" population growth can strain existing resource availability, but automation seems to have reached a point where population reduction won't mean there aren't enough people to e.g. mine the coal or farm the cattle or maintain the spreadsheets.
And to me, the spreadsheets is what it really comes down to. Specifically, the bureaucrats' spreadsheets and them not wanting their grandiose plans for the future of society disrupted by the messy business of people deciding for themselves whether they want to have 1.2 kids or 0.8 kids.
If population continues to decline, as it will if TFR remains below replacement, each generation will be smaller than the last so the problem, if it exists, is permanent even with no advances in life extension.
There are a number of variables involved other than TFR. Does lifespan increase, decrease, or stay the same? Is the average working life still 42-46 years, or is it longer or shorter? Have the automation/scarcity variables changed drastically or remained within a similar range to now?
I'm not a supporter of "Universal Basic Income," but if automation, AI, etc. continue to increase productivity and reduce scarcity levels, I suspect things will go in that direction.
We'll never not have problems, but I don't see population decline as inherently problematic.
Absent an AI mega productivity boom, the problem is that our old age entitlements become a Ponzi scheme absent an ever increasing economy, which requires an increasing workforce.
In the US, the Social Security entitlement is already a Ponzi scheme. The size of the "new investor" class (workers paying Social Security taxes) continues to decline relative to the population of "investors receiving the promised profits" (retirees). And an ever increasing economy can't inherently save it as it's currently structured, since Cost of Living Adjustments track inflation/CPI.
There are going to be changes to that entitlement, because there's no other choice than to change it, even if the change means just letting it collapse.
In my view, the LEAST likely change to it is a big Baby Boom that changes the worker-to-retiree ratio to keep it limping along. The only likely way to achieve that would be to send soldiers around forcing young couples to make the beast with two backs until the pregnancy tests come back positive, and then watch over them until the babies are delivered. Ceausescu found out how well that kind of approach goes over.
"And an ever increasing economy can't inherently save it as it's currently structured, since Cost of Living Adjustments track inflation/CPI."
That means that inflation can't save it, but an ever increasing real economy could. CPI stays the same, GNP increases.
Absolutely. And the most likely course to ever-increasing productivity is, IMO, more and more productive robots, etc. replacing fewer (or at least not ever-increasing) less productive humans in the production of goods and delivery of services.
I don't think that, as such, is really a utopian prediction. The first part of it is essentially the history of humanity since at least the beginning of the Industrial Revolution, and reduced population won't be all good times and noodle salad even if we find a non-dystopian way past the intermediate "nobody has a job anymore, which means nobody is getting paid, which means everyone starves" concerns.
“And an ever increasing economy can't inherently save it as it's currently structured, since Cost of Living Adjustments track inflation/CPI.”
This claim is simply untrue, and you have neither facts nor math that can back it up.
Further, the fact that the benefits are CPI-adjusted ain’t really a big problem. The fact that benefits grow until retirement with average earnings, not merely with CPI, is a huge part of the problem. Change that one thing and you would address almost 80% of the current SS shortfall.
I tend to think that the explanation is mostly technological change: better birth control. But there are a few things I think governments do that probably lower TFR: (1) sex education teaches kids how to use birth control and urges them to do so, (2) subsidizing birth control & (3) keeping teens locked up in school all day probably causes them to have less sex than they would if they had more free time while their parents are at work.
Better birth control explains why TFR is lower than it was 75 years ago but not why it has continued to fall. For that you have to add social inertia.
I think there has been some relevant technological change in that period as well, but I agree that the theory needs some epicycles. And https://www.statista.com/chart/30907/contraceptive-use-by-type/ shows that there are large cultural differences in the choice of contraceptive method, which presumably has some effect on TFR. I'd also expect cultures that prefer short-acting methods to experience stronger selection for genes that increase the likelihood of accidental pregnancy.
John Brunner’s Stand on Zanzibar, or not. Prophetic or pathetic much he saw we are.
I'd written four more paragraphs here starting from his theme, but noticed they pretty much led to and mirrored your last paragraph, hence I deleted them, oh well.
Caplan on heritability of fertility: https://www.betonit.ai/p/american-fertility-still-runs-in.
Caplan also wrote on government policy to increase fertility. I shall comment on it in a minute.
David, is your conservative friend aware that children of conservative parents may (and frequently enough, do) grow up to decide they are not conservative themselves? And that even if the children carry on in their parents’ footsteps by identifying as conservative when they grow up, many of the actual views they hold may be wildly un-conservative by their parents’ standards? In fact, even the parents’ own conservative beliefs have likely undergone changes, so that by calling themselves conservatives in their 20s and retaining this identity label in their 60s they will have caused the term “conservative” to change its meaning.
(Of course the truth is that “conservative” in the sense of “approach changes with caution and err on the side of keeping things as they are” has nothing to do with “politically conservative”, which can be more accurately summarized as “oppose whatever is associated with political liberals”. Thus the ideological implications of the two political terms change constantly and contain practically no information as far as what kinds of fundamental values drive people’s behaviors and beliefs.)
I believe he believes that political orientation is largely heritable, possibly for genetic reasons.
I recall seeing studies to that effect, but I also recall seeing the metric being something like “if your parents voted Republican you will be more likely to vote Republican” etc. I am pointing out that (1) it certainly isn’t a foregone conclusion (for instance a black swan event or momentous cultural shift can drive a lot of people to the other side, as has happened numerous times), and (2) this metric is nonsense in a world where “Republican” can have completely different policy connotations from one decade to the next. (Did your friend say this before or after Trump’s election, I wonder?)
What’s really getting passed on are personality traits, which by doing a lot of hand waving we can map to one political ideology or another—temporarily. I think it would be truer and more elegant to say something like “intelligent, virtuous people should have more kids, to increase the proportion of such people in the future.” To put it the way your friend did strikes me as a sort of empty grandstanding, which I think is why I bristled at it.
I think his view is that the left/right split is driven by underlying personality characteristics, probably genetic. My Substack (and others) is mirrored to the forum where we interact, so he may offer his own views.
BTW I am biased on this topic because my identical twin and I have for all of our adult lives had extremely divergent political views.
How different were other characteristics of your personality? It might be a case where two very different political positions were both consistent with the same underlying attitudes. Ex-communists sometimes become committed conservatives, and socialist George Orwell feels, from his letters and essays, like my kind of person.
I am probably more contrarian and fiercely individualistic than my twin is, but if I discount the different paths our lives took and the different sorts of social worlds we consequently inhabited and what we absorbed from them, he and I have quite similar personalities in many ways. It's probably exposure to those different worlds that led to our divergent politics.
Of course there's a sorta deterministic argument to be made that our lives took different paths because of our different personalities, but there I could probably point to different social influences during adolescence that caused our paths to split (during our formative years and into adulthood). But then a determinist like Robert Sapolsky might say it was personality differences that led us to those different social influences, and maybe this would go back and forth until he's claiming that when our zygote split one of us got a slightly different hormone cocktail than the other one.
Either way, what we'd then be talking about is hormones and personality, not politics, and I think we'd have conclusively shown that politics are beside the point.
Is your friend claiming that there are certain combinations of opposing political views that are compatible with the same personality, and that these are only an edge case and do not invalidate his ideas about parents passing their politics on to their children?