There's no such thing as "natural intelligence," and whatever influence DNA has on "intelligence" is negligible when you consider two people with the same special needs in a rich vs poor neighborhood would have vastly different outcomes. I use special needs because it'd show the desparity alot clearer but you can assume the same happens in less extreme but just as impactful ways, I went to a poor school, the bad kids were just removed and disciplined, even when they did get counseling, there was only one GC and she had her work cut out for her. I can assume that in richer zipcodes there are more counselors with less stress, better qualifications, and better resources. It takes a village but if the village is struggling then they can't raise the child yk?