what social commentary is Beatty trying to make for chapters 9 and 10?

I think the common point of both chapters is that Gunnar is still a kid. Though he does not show much enthusiasm, he does not show much desire to revolt either. Gunnar would rather play basketball. Basketball gives Gunnar a way to fill his time and it gives him an opportunity to demonstrate his disdain. Just like in high school, Gunnar handles the notoriety much better than Nick does. Though Gunnar often jokes, and anything is fair game for being the target of a joke, Gunnar seems serious when he speaks of Nick's developing problems. He even asks Yoshiko to make an appointment for Nick to see a professional.