I generally see single parenthood as a result of impulsive sex. While impulsive people may not listen to long term e.g. financial effects of unprotected sex on them or their children, they might more readily listen to social influences like peer pressure and their social image. Without the taboo of having premarital sex (in fact, it's glorified), they are more likely to have impulsive sex without contraceptives (it's more pleasurable, they forgot to buy some but want sex right now, etc.). Therefore, the single parenthood rate increases as those men flea their partners.

Think: kids are more impulsive than adults, but they seem to listen to their peers. They may not consider their health or future punishments from authority figures, but they'll listen to peer feedback and the effects of social influences. They'll do the bad thing if it makes them look cool even if they risk their well-being and punishment.

It also may have something to do with the women thinking their man won't leave them. Therefore, without social taboos against it, they have sex because they assume their man will stay and take care of the kids and assume they'll be together forever.

The man does it more often for the short term pleasure while some women do it because they are infatuated, want intimacy and romance, and impulsively think things will turn out for the best. Of course both things could be true for both genders (especially the pleasure part. In fact, both probably do it for the pleasure mostly, but the latter might explain some of it).

The social taboo might protect the more impulsive from making bad decisions. The success sequence says that you should (1) graduate high school, (2) get a full-time job, and (3) wait until marriage to have kids. 97% of people who do this escape poverty. The single parenthood rate obviously violates three and likely keeps poverty higher than it should be.

Expand full comment

Good post

Expand full comment

Our social norms evolved to work with our biology to create an evolutionarily fit society and we threw it all away like it was silly nonsense. Only the subcultures that hold onto tradition will survive.

Expand full comment

From an Olympic perspective: for a people to persist, each generation must produce sufficient offspring to allow a replacement generation to be selected that is equal in quantity and genetic quality to that which it replaces (because of mutations, this sustainable level of reproduction will necessarily be larger than the ‘replacement level.’)

The mating habits of peoples who fail this test are unimportant.

Expand full comment

"preventing the birth of unwanted children, meaning children born to unmarried mothers"

I don't think that's ever been a valid equation: even before the 1960's, there were (a few) women who wanted children but not husbands, and (many more) married people who didn't want to have a child then (if ever), usually for financial or career reasons.

I'm not sure how much impact that correction has on the rest of your argument.

Expand full comment

"As long as we only consider effects on adults...plus a net gain;" Just want to point out that this sentence is not literary true, at least not obviously, because of externality. For the whole society it's hard to measure but for the (potential) grandparents (or even close relatives), my guess is that it's more likely to be a loss. At least if we assume parents bear most of the cost, for grandparents of both kinds of women, having grandchildren is probably likely to be a net gain, both long-term and short-term, and I would guess that this a gain large enough to be comparable with the cost for women not wanting to have children to have them.

Expand full comment

Seems an accurate description of the state of affairs (accidental pun) to me. Upcoming economic conditions, then, might turn the ship around, huh?

Expand full comment

I think most of the discussion about fertility, sex and related issues done by economists and such, typically lack any deep evolutionary basis, that is its easy to come up with reasons in the form of X causes Y, harder to see why evolution would make it such that X causes Y, the result is an additional layer of filtering as to what becomes a plausible theory.

Evolution is also a blind idiot god, the fact that it only selects for reproductive success yet its creations came to value sex etc. and not reproduction is bizarre, the effects of decoupling sex from reproduction via contraception and such is likely to result in all sorts of other oddities, as is the rapid shift from our ancestral environment to our modern richer one. We moderns can send a man to the moon and back, split the atom, create artificial minds, yet the one thing we can't do is the one thing evolution optimised us to do, instead we have maxed out on everything else, from refining food in such a way as to trigger the greatest satisfaction response to spending time watching morality porn created by Hollywood to trigger the greatest emotional response, to doing math and science something whose biological predispositions would have proven useful, etc. Perhaps evolutionarily wealth was the big mistake, or the psychological content of the human mind.

Expand full comment

>It is widely believed, may well be true, that children brought up in a single parent household have worse lives than those brought up by a married couple.

On average, obv.

I have to say that I was fortunate enough to meet my soulmate, after failures


Before we met, she had known more partners and had decided she would be alone.

Expand full comment