Scout, Jem, and Calpurnia return from church to discover that Aunt Alexandra has moved into the Finch's house to provide "feminine influence" for Scout.
Alexandra has decided Scout is not enough of a girl, a kind of gender prejudice.
Alexandra is proud of the Finch family's social status in Maycomb, and immediately begins to socialize in Maycomb. Scout thinks good people are defined by doing the best they can with what they have, but Alexandra seems to believe that the older a family's history, the better the family is. Alexandra even forces Atticus to teach Scout and Jem about their family history. But this strange change in Atticus makes Scout cry, and with relief he gives up.
Scout's inability to understand the logic behind Alexandra's insistence on the value of social class reveals that there actually isn't any logic. Instead, this worldview is just another form of prejudice, this time economic and social..