Arts window on the world

Cities are said to "not reproduce themselves", ie the birth rate to women in a city is not sufficient to replace the natural death rate of a city.

Now some of this may have to do with an increased death rate in a city, since sanitation appears to be a relatively late invention. Of course, human caused deaths - accident, murder, strife, etc - would also be higher in a city. But there would also appear to be another problem.

Female fertility appears maximized for a unique male set of pheromones. Thus, a woman with a lot of unique male hormonal "triggers" would have a higher fertility rate than one contending with multiple non-unique triggers. Families in farming, faming being a "solitary" occupation, would generally have a higher fertility rate than families in cities.

I would be interested to see what kibutz figures in Israel would say about this. It appears that prosititutes have a lower fertility rate than their occupation would initially imply.

Again, this would explain the popularity of the purdah in India, where only artificial separation of women would overcome the lower birth rate of effect of the high population density.

This would also explain the desire in Genesis 11 for people to spread out in the world rather than gather in a single city.