When “there is no such thing as society,” but “it takes a village” to raise children, it’s obvious that many choose to simply not have children. There is also a correlation between improving material conditions and lower birth rates, but that only partially explains the current situation in the west.

I learned something interesting about the average gap between children in different mammal species recently. Great apes, I think it was orangutans specifically, have babies roughly eight years apart, as that’s how long it takes for an orangutan to mature enough to not need constant care. This being while orangutan babies are more mature and capable at birth than human babies. Whereas in hunter-gatherer human communities the gap is more like four years, not because a four year old is mature enough for the mother to have time to care for another infant, but because child rearing is a communal responsiblity; she has help. In the US this gap has been reduced even further to just two years, even though the average mother in the US has essentially no help with domestic labour and likely has to participate in wage labour as well.