Thankfully no. My school had lot of non asshole kids (I think kids are usually trained to be selfish assholes) who were kind and patient enough to socialize with weirdos (aka undiag autistic kids) like me. They were the reason I developed somewhat functional (though absolutely not ‘normal’) social life in adulthood. We are still friends, unfortunately we are spread all over the world nowadays cause life.
I think culture matters too, autistic spectrum friends of mine who went to US schools tend so say having very different experience. Opposite anecdotes were from kids in asia.
I think both traits are taught and at the same time innate at the same time. While growing up, we learn an abstract value system that shapes when we want to be selfish and when not.