&gt; it&#x27;s something both their parents transmitted culturally&#x2F;behaviorally because they themselves converged by living together<p>I very much agree and I think there is even more here:
The people in charge of their education (mother, father) weren&#x27;t &quot;drawn independently&quot;, they are two people that chose and love eachother (at least for some time).<p>People who marry each other tend to come from similar cultural background, or they can share some interests.  All of this can then be transmitted to their respective kids.<p>After all Jack &amp; Oskar&#x27;s parents probably  both liked white jackets before they even met.