Is it not well known that smart people tend to have smart children (though there is also regression to the mean). I’m not talking about it being correlated wit

Is it not well known that smart people tend to have smart children (though there is also regression to the mean). I’m not talking about it being correlated with other traits, just intelligence itself being heritable. Well, I say “itself”, I imagine the same genes also have other impacts on other unknown things that are not noticed, because the interactions between genes is super complicated (I think?), but that’s practically the same as “itself”. Why else would intelligence be attractive, if it weren’t heritable?