Sunday, January 22, 2017

The Birth Control Basilisk

An ongoing question I've talked about a few times before is that at least some of our toughest social problems are really technology problems. That is, not problems of a lack of technology, but of a surfeit of neutral or even beneficial technology which is having unexpected negative side effects. Mass illegal immigration is mostly a problem of cheap transport, for instance.

I mostly think about the declining birthrates in much the same way as I think about the increase in obesity (which deserves its own post for sure). Specifically, that technology has produced an environment so unlike that to which we’re evolutionarily adapted that people’s instincts no longer produce reliably good outcomes.

In other words, reliable contraception and abortion has been like a basilisk. It short circuits what had previously been a very successful evolutionary adaption which used to have high reproductive fitness. It leaves humans like the moth circling the light bulb, thinking it is the moon and flying in circles until it drops of exhaustion.

What are the instincts that people have with respect to children and reproduction?

1. People have a very strong, uncomplicated and concrete desire to have sex, ideally right now. They don't need marketing campaigns to make them want to do this. Oddities like Japan aside, people seem to have no problem getting laid.

2. People have a somewhat strong, but quite complicated, abstract and malleable, desire to have children, at some point in time.

3. People have a very strong, uncomplicated desire to love and care for the children they have.

#2 and #3 are deliberately split into two parts. As the great Gary Becker put it, you don't love your children as much as you learn to love your children once they arrive. There was usually the option to have one more child, which you chose not to do, often as part of a quite sensible cost/benefit tradeoff. Of course, if people had an unplanned pregnancy and had another child anyway, they'd still love and care for the child. But the fact that each child gets loved intensely once it arrives doesn't cause people to want as many children as possible. The love only kicks in after they arrive, and the prospect of loving another child in the abstract does not exert nearly the same overwhelming pull.

In other words, traditional reproduction worked primarily through #1 and #3. A strong desire to have sex ensures children are produced with fairly high regularity, because birth control is either non-existent or unreliable. A strong desire to care for children once they arrive ensures they live to adulthood if resources allow. #2 served mostly as a general background reinforcement. This is the environment we all lived in from 10 million BC until the 1950's or so.

The whole idea of it being a contentious question whether you chose to have kids or not is, as far as I can tell, a shockingly recent question. If the only way you could so choose would be to either a) not get laid, or b) rely on methods that require practice, discipline in the heat of coital moment, forward planning and/or health risks, the discussion would be largely moot.

With birth control, childbirth has been largely disconnected from being a necessary consequence of getting laid. It seems that most unplanned pregnancies are teenagers who are still learning the ropes of birth control, the very poor who simply can't afford it, or people with very low forward planning skills. But regardless of how you cut it, in the modern era it is very easy to take precautions that mean you can have sex for an extended period and not get pregnant.

As a result, we’re now expecting the second, weaker desire to do the job where previously the heavy lifting was done by the first. You have to choose to have children. Is it a wonder that this doesn’t wholly succeed?

This doesn't mean that the problem is impossible - social pressure can be a powerful force, if the right motivations and incentives are set up. But make no mistake, we're expecting new social engineering to reproduce a result that was previously done just by our evolutionary adaptions.

I suspect that we are only recently finding out that the majority of human survival and reproduction was actually driven by unplanned or unwanted pregnancies. We now suffer from a want of unwanted pregnancies, and we don't know how to make up the difference.


  1. To begin with, let me tell you that I enjoy your blog.

    About birth control, I used to think like you and I still think that your theory is true. But now I think it's incomplete. Things are a bit more complex.

    I agree with all your sentences except this one: "from 10 million BC until the 1950's or so.". There have been previous eras of birth control and low fertility. When the Romans were in a high fertility phase, the Greeks were in a low fertility phase. When the Barbarians were in a high fertility phase, the Romans were in a low fertility phase.

    How is this possible? Did the ancient Romans have the "pill"? No, but there was a weed called "silphium" that was a contraceptive. It was used so hard that went extinct. Don't forget about infanticide either. Many Roman people abandoned their newborns so they died. Chritians were famous for refusing to do that.

    So #2 depends on the phase of the culture. Typically, cultures start being high fertility and they want to have a lot of children.

    Remember Abraham? According to the Bible, God promised a lot of descendants: "I will make your offspring like the dust of the earth, so that if anyone could count the dust, then your offspring could be counted." (Gen 13, 16 NIV). He was so happy. It was the best gift he could imagine. I say to my students: "If Abraham was a modern man, he would have answered God: 'I don't give a shit about future generations! I want to live my life as comfortable as I can and fuck the future'.

    The same as primitive Romans and Greeks. They did not see children as a burden, as something that reduced their quality of life. They saw children as a gift. In traditional, patriarchal cultures, people try to have as many children as posible.

    With time, the culture prospers, wealth increases, the culture gets matriarchal, people get more lazy and value comfort. So children are seen as a burden. You must have one or two, but you don't want more. Then people look for ways to reduce birth control. Whether is silphium or the pill, contraceptives are used. When there's a will, there's a way.

    Why didn't 19th century scientists try to discover a contraceptive? Even if they hadn't succeed, they didn't even try. They didn't see children as a burden, thats'all. People tried to have more food and wealth to feed their children and not to have less children. Novels like Oliver Twist try to protest the poverty of children, not the lack of planned parenthood.

    So it's a cycle. In the decadence phase, people get comfortable, use contraceptives, have low fertility and are replaced by a high fertility culture (Islam, I'm looking at you). So ideology drives technology and not the other way around.

    1. Awesome comments. I definitely agree that my theory above is incomplete, and the time-series cultural variation of motivation #2 is something I haven't thought about much, but surely seems correct. I don't know enough about the early Greek and Roman societies, but it implies something else is going on. At a minimum, this is going to operate in addition to the effectiveness (or otherwise) of birth control affecting motivation #1, so I still think that there's a big technology component that explains the recent time series. Though your point that the Victorians weren't looking for better birth control is something I need to think about more.

      One possible explanation for variation in motivation #2 might be the economic value of children. In other words, when you need more hands to work in the field, or more able bodies to defend your tribe against predation, children are a fairly uncomplicated blessing. But once you don't need children to provide for your retirement, hedonism is more likely to take over. Of course, this still doesn't explain cross-sectional variation within the same society - Mormons and Hassidic Jews aren't notably poorer than other groups, and even if they were, their fertility isn't because it's profitable. So there's other stuff at play. I don't know if this would have had any role in Greek vs Roman society - purely cultural factors may be the bigger factor.

      Perhaps another way to think about this is as follows - the reduction in birth rates may be because there has been a cultural shift, but it's probably not just because there's been such a shift, and it's not even obvious that this is the primary cause.

    2. Declining birth rates in Rome is one of Will Durant's big themes in Caesar and Christ (, for example: 'Marcus Terentius Varro mourned the low native birth rate that was transforming the population of Rome; "formerly the blessing of children was woman's pride; now she boasts with Ennius that she 'would rather face battle three times than bear one child.'" And Augustus passed laws specifically focused on boosting the native birthrate, for example ` The mother of three
      children acquired the ius trium liberorum - the right to wear a
      special garment, and freedom from the power of her husband. ' I'm not sure if any of it worked.

    3. Huh! I'll have to check it out. Does Durant say how this reduction in birth rates was happening - was it infanticide, the birth control weed mentioned above, or something else? I always assumed that infanticide would be psychologically difficult for most people, meaning that a decline in birth rates required some technological innovation, but maybe I'm mistaken.

  2. This echoes what I have said on the subject

  3. This echoes what I have said on the subject

    1. Interesting stuff. Thanks for passing them on.

  4. On the other hand, what is the variance in family size? Is it lot's of couples having only one child, or a lot of childless couples and a lot of couples having 2-3 children, leading to a low average?

    Given that the desire to have kids - let's call it broodiness - is likely to be somewhat hereditary, there will exist an evolutionary pressure favouring broodiness. As a result, over the generations the birth rate should increase again, even with the ready availability of contraception - people who don't want kids won't have them, and thus won't pass on their low-broodiness genes.

    1. That's a great point. In the long run, you'll definitely end up selecting for those that choose to have more children - in other words, evolution will select for higher levels of motivation #2. The worry, however, is what else is going to be selected for along with that, and what the resulting society will look like. At the moment, we seem to be selecting for the religious (which may well be a good thing), but also for those with low impulse control and bad forward planning skills (which seems disastrous). Humans probably won't be selected out of existence, but civilisation well might.

    2. "On the other hand, what is the variance in family size? Is it lot's of couples having only one child, or a lot of childless couples and a lot of couples having 2-3 children, leading to a low average?"

      I think I can answer that, at least partly. Based on data from Poland (made the transition to low-fertility sometime in the 80s/90s):

      These stats analyze families WITH children. Most have 1-2 kids, 3 and 4+ kids in families combined are a bit above half as frequent as families with either 1 or 2 kids. Given the Polish TFR of 1.2 (as of 2014), I estimate that there are roughly as many childless women as there are women with 3-4+ children.

    3. @AbuDhabi - Huh, that seems to imply a fairly strong selection towards fertility, more than I would have guessed. Although it depends a lot on how heritable the traits themselves are. With things that have a cultural component, it's hard to know, as it's not like birth rates have been shooting back up in the west.

  5. I think if you look into it you'll find all cultures regulate fertility to approximately match birth rate to death rate. Very rarely are there enough spare resources to permit rapid population growth (the past couple hundred years being an exception). Look at customs related to first marriage age for women (as low as puberty in societies with high death rate, as high as 25 in northern europe for instance). Also customs which discourage sex while breastfeeding (which can be delayed as long as 2-3 years).

    Of course the death rate, mainly from disease, has usually been much higher, so that throughout history most women had to have, on average, 5-6, possibly up to 7 children average to ensure population stability. So there wasn't as much need for fertility control as there is now. But still throughout history all cultures intrinsically seek to regulate fertility.

    1. Regulating birth rates by discouraging early marriage is an interesting idea. In other words, if you can't have contraception, you need to stop people getting laid in the first place. That said, my understanding was that it had more to do with having enough resources to support a wife or child. Even if the general marriage age was high, a rich man could still get a young bride. So the tendency to have more children was there, the restriction was on the specific ability to support them, rather than a general cultural prohibition.

      So when regulating fertility had to happen through refraining from sex, it was unlikely to ever spiral out of control towards population decline, because the desire to get laid was always a strong pull in the other direction. But that counterbalancing force isn't there any more.

      In other words, there was always a need towards regulating fertility, but doing it by limiting sex always struck people as a very different and less desirable outcome than limiting births directly.

  6. It's rather a cultural thing methinks. Sure, "birth control" wasn't available historically but infanticide was so widespread, even in Middle Ages, that it got into children's fairytales! Reinstituting patriarchy (and making parenthood high-status) should fix the problem of sub-replacement fertility (even without the ban on birth control).

    1. I hadn't realised that infanticide was a common practice. I can imagine it happening sometimes, but it seems like such an atrophication of the maternal instinct that I'm shocked at the claims it was widespread. That doesn't mean they're wrong, of course.

      I would still guess that taking a pill each day is a lot psychologically easier than abandoning a crying infant. One doesn't need the claim that there were *no* other birth control methods, only that the modern ones are a significant enough improvement that they'll have a considerable effect even if you hold constant the culture of the population.

      Which is another way of saying your point - you need to push a lot harder on the culture of the population to undo what technology has wrought.

  7. It is difficult (impossible) to separate the cultural and biological. I always wanted children (loved kids etc), but felt this wasn't the world to bring them in to. Was that my biological subconscious informing me we were overpopulated, or a conscious cultural choice? Who knows.

    One thing I have thought a lot about lately is our 'obligation' to have children. I can't help but think that the modern individual hedonist who 'chooses not to burden oneself with children' is a serious insult to one's ancestors (and even our parents). Do we not owe it to those before us who at times sacrificed all to continue the tribe, to at least maintain bloodline and necessary demographic growth? What right do we have to consciously extinguish our family or society for our individual pleasure?

    PS. I'm not familiar with many cultures, but pre-Islamic Arabia killed a highly significant number of its female offspring as they were seen as a resource burden. Islam had to ban the practice.