Well if that is so there shouldn't be any social incentives to encourage procreation, but every society in the world values procreation heavily, most traditional societies ostracize people who can't procreate. If biological insticts were enough why social incentives/ostracization. How do you explain the social stigma of being childless.
<wild conjecture> Perhaps the social stigma is an evolved response. Maybe one method humans have evolved to incentivize reproduction is the ostracization of those unable/unwilling to have children. </wild conjecture>
