Books, which are still a vital part of schooling, have been banned, so the schools in the novel are places where children are indoctrinated by television into living according to societal norms. Clarisse describes the school as "unsocial," which she thinks is ironic because she herself is branded anti-social.
"An hour of TV class, an hour of basketball or baseball or running, another hour of transcription history or painting pictures, and more sports, but do you know, we never ask questions, or at least most don't; they just run the answers at you, bing, bing, bing, and us sitting there for four more hours of film-teacher. That's not social to me at all."
(Bradbury, Fahrenheit 451, Google Books)
Despite the odd creative outlet of painting, it is clear that these schools are not concerned with educating the minds of students; instead, they are concerned with telling the students what to think about any given subject, instead of how to think, without any method of questioning or analysis. After school, students are so exhausted by the constant flow of superficial information -- which comes without the mental exercise of asking questions -- that they treat mindless violence as a fun after-school activity.