Genetic Family Size Preference and the Re-Arming of the Population Bomb

What evidence is there that there is a genetic component?

This may be right, but not because of the reasons the author supposes.

I really doubt there is a strong genetic component to desiring a certain family size, but I believe along with most other people that wealth strongly influences family size.

The population bomb may re-arm as economic trends of rising poverty and working poverty persist. As the wedge between rich and poor grows with many more on the poor side of the divide, family size may grow.