It's funny you gave example of bullying. It's again another thing that seems very common in USA. I was honestly shocked that there was so much bullying in school. And teachers apparently don't do anything except telling the victims to toughen up, or learn to deal with it yourself.

Yes some children are bad, but it's largely shaped by environment on what they feel confident doing. For an extreme example, a bad child in any other country will not go shoot up the school. Bullying feels similar. It is natural that children will form groups, include people they like, exclude ones they don't. Rude ones are normally excluded from nice groups. And if it's anything actually harmful, adults' (parents or teachers) interference stops it. I think the American individualism starts young, when someone is bullied, even their friends won't stick with them to not be victims themselves. That just isolates the victims, and the bullies feel empowered.

It is my perspective from outside as I didn't go to school here. So forgive me if I don't understand it completely, my knowledge of school in USA comes from Internet and a lot of philosophical conversations like this with people in my life that went to school here.

My school experience wasn't perfect, me and this other guy were the shortest in our class. It was even kinda officially recognized because teachers ordered students by height in assembly (every morning). I had people that looked down on me, and people I looked down on too. Some small physical fights (not height related), and verbal ones. And a lot of teachers' intervention. But people valued education, when I learned how bullied being a nerd makes someone here, and hearing the details, and the apathy of the teachers, I was shocked.

Similar thing with the race problem. We had everyone go to the same school, our parents (and prev generation) would not go to each others house to eat, even if they get along socially. It was a social taboo, but I will not do that because I grew up with my friends. And they're just my friends, and the social rules seem arbitrary to me. And it helps that we're taught about equality, and how the old way of separating/discriminating people was wrong. Previous generation might not be able to let go of their habits easily, but when they no longer control society, most of it will be gone. Also, in my generation (friends and cousins), I have seen so many marriages that would not have happened in previous generation.