Long ago I read &quot;essai de prospective demographique&quot;[1] written by French demographers.  They were raising the concerns you mention and were trying to warn the public of a coming &quot;demographic winter&quot;.  So your point of view is not rare.<p>That being said, even if a demographic winter would probably have very adverse consequences, as it is not clear how well the industrialized society would fare if the population was drastically reduced, I have hard time picturing how that could lead to the complete extinction of mankind.<p>There will always be pockets of population with high fertility, at the very least among highly religious communities.  Even if as you suggest reproductive behavior is transmitted, that works both ways, and simple natural selection will always, in the end, favor the reproductive behavior that leads to increasing numbers.<p>Demographic winter is a serious concern, but I can&#x27;t imagine it leading to a complete extinction.<p>1. <a href="https:&#x2F;&#x2F;books.google.fr&#x2F;books&#x2F;about&#x2F;Essai_de_prospective_d%C3%A9mographique.html?id=lz9mPQAACAAJ&amp;hl=fr" rel="nofollow">https:&#x2F;&#x2F;books.google.fr&#x2F;books&#x2F;about&#x2F;Essai_de_prospective_d%C...</a>