The Sumerians, the Egyptians, The Greeks, The Chinese, The Romans, Post Rome Europe, Persia, the Turkic Empires, India, the Incas, the Mayans, The Aztecs, The Japanese, and with the exception of the past 30-40 years nearly the whole of the industrialized world, with a few exceptions really beginning to stand out in the area of birth rates which at the very least were at replacement level.... and every single one of them paternalistic...
Compare to your society, which has basically cut its own throat. Without the birth rates and absent the technology of the last half of a century you now have a society that absolutely implodes once there is no longer enough labor to grow crops or conduct industry to sustain itself. Without some form of societal contract... aka marriage... for the rearing of children you have something like what is happening in the African American community today a broken model where the guy doesn't give a crap and the girl is left alone to raise the kids. Granted you could have some government type communal system but now you've moved into Brave New World or even 1984 level Dystopia here...
the problem with universal reproductive determinism is that it cuts out half of the equation, which leads again to African American style failed familial structure or the end of the society and some nasty counterrevolution that makes Saudi Arabia look like Amsterdam from both genders (Which now that I picture it would be hilarious, think Phyllis Schlafly crossed with Ayatollah Khomeini).