> Traditional societies had all sorts of taboos around sex, Yes, but all of those taboos are there for a reason. You may not know the reason for Chesterton's f

> Traditional societies had all sorts of taboos around sex, Yes, but all of those taboos are there for a reason. You may not know the reason for Chesterton's fence, but there is surely a reason. It is so costly to transmit a taboo across time that you don't get random taboos that survive and don't perform a socially necessary function. > Why can't we develop similar taboos around having too many children? I think there is already social disapproval for having more children than you can take care of in most places. Traditional societies even had mechanisms for infanticide -- child abandonment -- that were replaced in the middle ages with state sponsored orphanages. > Sure we need some children to continue, but what if the optimal number of children is 0.1 per woman? Well, if that were the case, then it would be the norm already. Of course we know it is not the case because that geometric series goes to one. And we know it is greater than 2 because there are plagues, wars, etc, and populations need to be able to recover from these quickly. And we also know that a larger group is generally stronger than a smaller group. These groups compete with each other to see which will win out. This even transmits to democratic societies, obviously, so if people unconcerned about CO2 have more kids then the society will be dominated by those unconcerned with CO2. Thus any belief system which results in having fewer kids is put at a disadvantage both in terms of biological evolution as well as social evolution. Now fortunately no nation is an actual democracy, it is always controlled by elites to some degree, so you can hang on for a while with a shrinking population that follows your beliefs, but at some point things reach a tipping point and you lose power if your beliefs result in having fewer children than the competing social system.