I have different unique cities with their own special features. For example: one city has farms and raises animals (Cattle, chickens, etc...) and therefore has the ability to talk and understand them. The people who live next to the sea can breath under it. And so on...
Can I have a city that can controls their children's sex, where couples can decide if they want a boy or a girl?
I have 2 questions :
Would it lead them to Extinction? Maybe a huge war starts and most of the people decide to have boys so they can fight... if 80% of the population are male, the birthrate will decrease a lot (fewer females to carry children), and city will shrink. Or, for example, a city discovers a gold mine; their society uses only males for mining, so most couples will end up selecting boys to generate gold.
What benefits would such a feature provide the city? I mean, in what ways will it differ from other societies? Will being able to select sexes for their children give such a city advantages over other normal cities?
These are the constraints on their society:
You cannot set a rule enforcing sex selection (For example: "Each couple must have at least 1 girl.")
Intermarriage between cities are discouraged because intermarriage causes cities to lose power and prestige.