How does McMurphy react to the patients?

McMurphy might brag about being a psychopath, but it is easy to discern the ruse, for he is boisterous, entertaining, quick with words, and oddly gentle in his mannerisms. He clings to the idea that he belongs at the ward, but we already sense that he is the only lucid patient in the ward. We will rely on him to illuminate the true sanity and humanness of others. Even so, he is there for a reason. It is only because of statutory rape and avoiding the work farm, or is there a real problem with his open flouting of authority? Does his independence go too far in a repressive society that is not ready for the likes of a countercultural free spirit?