Women who are childless past a certain point may be biological aberrations.

Hormonal shifts occur during pregnancy that change a woman's body and mind, perhaps permanently. Hormones and neurotransmitters have a profound impact on our feelings and behavior. Although science hasn't quite parsed out what these hormonal shifts do nor how long they last, it is safe to assume that evolution has kept them around for a reason. It seems plausible that the changes that occur during pregnancy may even be so pervasive and impactful that they represent a distinct biological life stage for women.

For a long time, it seemed highly exceptional to me that evolution would forget to instill into women a substantially strong enough desire for children such that large quantities of twenty-first century women wait or even refuse to have children. But then I realized that I had gotten it completely wrong.

Before birth control was common, a childless woman did not have to have a desire for children on order to get pregnant. She only needed a desire for sex. The desire to care for a family only had to come after she already birthed her first child. This isn't to suggest that women have no desire for children before they actually conceive them, only that there is at least room for variation among women in how fiercely they desire children since the desire is not necessary for them to conceive.

As we all know, it is very easy for a fertile woman to get pregnant. She just needs to accept the advances of a man she finds suitable. In the past, almost all women who had the physical machinery to do so, the majority, became pregnant. Very rarely is a woman so unappealing that there is no man who is willing to inseminate her. This must mean that evolution sculpted women's psychology more around the guarantee of getting pregnant rather than the contingency of her not getting pregnant. Even in those cases of women actually being undesirable, evolution only necessarily needed to gear them towards being more sexually aggressive rather than increasing their desire for children.

Unlike women, men are not more or less guaranteed to be able to create children. Only something like 40% of all men historically reproduced. Considering how much more common it was for men to fail to reproduce, it seems plausible that evolution would have taken into account male childlessness to a much greater degree. To be a childless man is completely normal.

For a young and desirable and intelligent woman to continuously put off childbirth is basically an phenomenon of the past 70 years. Evolution has no script for these women. Their unconscious software is basically bugging out, trying and failing repeatedly to get her pregnant. It's a bit like the destruction of chemical balance within one's body that occurs when somebody eats way too much sugar over a long period of time: Sugar causes them to feel hungrier and eat more, their body stores fat more readily because of the chronic over release of insulin, which leads to all kinds of life-deranging problems.

If this is true and women are basically becoming unbalanced in some way by proceeding into old age while not having children, then these women should be the ones who are more likely to have novel and perhaps sometimes even antisocial attitudes that make no sense for society in the grand scheme of things.