Ch.23.6 What gives the Finch family " background" accordion to Jem?

Jem says that there are four different kinds of people in Maycomb county: "ordinary" people like themselves, people like the Cunninghams in the woods, people like the Ewells by the dump, and black people. Each class looks down upon and despises the class below it. The two try to resolve exactly what separates and distinguishes the categories of white people. Background doesn't seem to matter, because all the families are equally old. Jem thinks these class definitions have to do with how long the family has been literate. Scout disagrees and thinks, "there's just one kind of folks. Folks."