No child of six years of age could have told of the many dramatic events that occurred in To Kill a Mockingbird. Harper Lee begins with the adult Scout's explanation to let the reader know that it is told from the future perspective of the narrator. Scout begins with the tale of Jem's broken arm in part because it was the climactic event of both of their lives. Addtionally, it foreshadows the ending and leaves the reader wondering how the arm will be broken. It also gives the reader a notion that all's well that ends well: Scout, Jem and Atticus will live on past the events of the story. It is a feel-good opening to a story full of mixed emotions, humor and hate. The family history is a way of not only introducing the characters, but to show how the generations of the Finch family react to the ways of the world, both good and bad.
In the book "To Kill a Mockingbird" Scout has grown and matured and wants to bring the reader to the events of the year that had changed her life and had matured Jem and her. She begins the story by telling about Jem's arm so that the reader will have an understanding of the children's ages, the kind of person Jem is, and her relationship with her brother.
The background of the town and the interaction of the people as well as how Scout first viewed her own is also central to the theme of change. The reader believes that it is a nice quiet and comfortable sleepy little town. However, as Scout matures through the events of Tom Robinson's trial, the reader and Scout begin to see the ugliness that lies beneath in the behavior and prejudice of the townspeople.