Growing up as a younger child in an atomized, low-fertility WEIRD world, I was until recently in the historically anomalous position of not really having any idea what children are actually like. (I have some memories of childhood, of course, but that's not the same as field observations with an adult intellect—everything from before age 14 or so feels insufficiently continuous with my current self to really constitute knowledge in my possession.)
It's not clear to what extent people really have anticipation-controlling beliefs in the absence of lived-experience data, but the narratives we think we believe come from what we read.
One such narrative relevant to the topic-focus of this blog is the progressive mainstay, "Psychological sex differences are fake/socially-constructed." A metacontrarian counternarrative that I got a lot of exposure to as I sought out ideologically-inconvenient science during my twenties was, "Overeducated out-of-touch liberals think that psychological sex differences are fake/socially-constructed, until they finally have children of their own and see for themselves how much is innate." As I slowly came to grips with just how deeply the progressive coalition has been systematically lying to me about everything I want and value, I grew to mostly accept the counternarrative.
And so as I've recently gotten some field data thanks to some of my friends actually having children (!!) in the past few years, it has been a pleasant surprise to notice the metacontrarian counternarrative making failed predictions in the form of my friends' kids' individual personalities not being overtly stereotypical: friend's daughter's (age 3) fantasy doll play frequently revolves around epic battles of good guys vs. bad guys (with the bad guys regularly being killed or put in jail); other friend's son (age 2) is the subject of adorable anecdotes about wanting to hug and not hurt people, and his current special interest is endlessly rewatching the documentary Babies. The glorious Hydeian counter-counternarrative is confirmed: maybe some sex differences are real, but the effect sizes are so small that you really should just treat everyone as individuals, not out of ideological commitments, but because it actually makes sense!! Rah! ⚥ 💖
On the other hand, if I'm remembering my Maccoby (RIP 😢) correctly, a lot of the standard social-play differences emerge a little bit after toddlerhood. So I'm bracing myself for the possibility of a dreary counter-counter-counternarrative in a few years.