Children are always, in every society, very costly to the immediate family that cares for them, and any benefit accrues to the greatly extended family, tribe, r

Children are always, in every society, very costly to the immediate family that cares for them, and any benefit accrues to the greatly extended family, tribe, religious sect, kingdom, state, or market economy. The idea that people decide to have more children simply because they are struggling, is a patently ridiculous and alienating belief about ‘other’ people. Rather, they are forced or rewarded for ‘uterine labor’ as you say, and therefore what you say does apply to the social organism as it evolves to greater complexity and specialization, and to the individual only through the reward structure. But, back to my point, which is that this economic specialization is not at all causal to living standards, which could be absolutely awful and yet provide no incentive for childbearing. This tribal structure has a common name: ‘extinct’. Conversely, an unspecialized tribe could enjoy wonderful living standards, and they would be expected to grow prodigiously. And finally, if a previously unspecialized tribe becomes specialized, and therefore lowers their birth rate with the same economic output, their living standard will increase. Okay one more to drive the point home. Consider the Mongols or Wahhabists. These were low-fertility specialized tribes that enjoyed massive increases in living standard, followed by such a massive increase in fertility that it would eclipse the population growth of all other tribes. Market participation is the force that both drives specialization away from ‘uterine labor’. Additionally, it reduces the value of all outputs such that there is not enough prosperity margin to produce children. Imagine a high-fertility tribe that can no longer afford to feed and house children because the market price naturally drops for their goods over time. In this case, the causality clearly works in the opposite direction. So I will state the obvious, that improved living standards do not cause low fertility, but market participation does, and the result of this combination is increased living standards.