In chapter 23, Jem and Scout learn a great deal about the prejudices woven into Maycomb's society. Jem first learns that women aren't allowed to serve on juries and that there is something innately unfair about the way jurors are selected. Aunt Alexandra then chastises Scout for wanting to play with Walter Cunningham, calling him "trash" and forbidding it. Jem and Scout try to rationalize the social hierarchy of adults in Maycomb, and Jem believes that somewhere along the way, families like the Finches must have gotten ahead because "one of ‘em … learned a hieroglyphic or two and he taught his boy."
The children are dismayed with the way adults display cruelty and harbor resentment toward each other. At the conclusion of the chapter, Jem thus surmises that Boo Radley has stayed locked away in his house for so many years because he wants to stay inside.
Scout and Jem have spent many of their childhood hours imagining the world of Boo Radley, even daring each other to touch Boo's door. He has remained a man of mystery to them, and they have been told that he is kept locked away because of his own mental challenges. Yet in this statement, Jem begins to believe that maybe Boo's world isn't the one in need of change. Perhaps being locked away keeps him in a safer and less troublesome environment, and maybe he therefore stays inside voluntarily instead of being forced to live there. As Jem recognizes that the adults in town constantly "go out of their way to despise each other," he also realizes that perhaps Boo chooses not to participate in Maycomb's prejudiced social interactions.