Blog comment in response to Sex and Fertility in the Post-Petroleum Age by Jan Lundberg,
27 July 2010
Look at Historical Evidence
Developed societies like ours, with sanitation, medical care, artificial contraception, and optional bottle feeding of infants, are a recent exception in the history of humanity. The prevailing patterns over the history of our species have involved females becoming fertile at a somewhat later age (16-18 years old), due to less adequate food supply; prolonged breast feeding of infants, which suppresses fertility and ensures a longer inter-pregnancy interval; higher infant and maternal mortality; less investment of effort and calories in infants that have a poor chance of survival or less social utility (e.g., the Greeks abandoning deformed infants at birth); a certain amount of infanticide, usually by men, who kill a woman's children by a former male partner; etc, etc.