Interesting . Very relevant to Spengler's theme of "dying" people. I recall some people asking why, when we are wealthier than at any point in history, people try to make economic rationalizations not to bear children. The conclusion seemed to be a warped value system and that those people who did not wish to breed were fundamentally anti-human and deserved to become extinct.
Whatever the case, the desire to have children is certainly an evolved trait that ensures the survival of the species. It may never have been truly pleasurable but rather an obvious necessity. Evolution does not plan, however. It only takes into account selection pressures in the present.



