Throughout "To Kill a Mockingbird" Jem see-saws between childhood and adolescence - at times has a wise head on young shoulders and at other times loses his cool. His father looks to him to set a good example for his young sister. Jem finds it hard to understand why life is not always fair and he wants to define people and put them into compartments as he grows older. His innocence of childhood is gradually stripped away.
Jem, Scout and Dill's fascination with Boo Radley and wanting to find out why this man hides in his home is well documented. Boo is a bit of an enigma to Jem, Scout and Dill. The Radley residence is scary to them but at the same time holds out a great fascination. They want to know what goes on behind the closed doors and get Boo to come out - he keeps himself to himself and never leaves the house and there are tales circulating from the gossip mongers as to what has gone on behind those doors. .
They ask themselves why anyone would want to do that - hide away? Their initial view is that there must be something evil about this man, but gradually their own prejudices on this subject are broken down after Miss Maudie and Atticus gave their own understanding and knowledge of Boo Radley and his hardship.
Jem's learning of how to deal with racism from people within their community, at school and from family members and how they manage to disarm it on occasions or just learn that life is sometimes unfair. .
'To Kill a Mockingbird' is a perfect book to use as an example to show what racism was in America in the 20's and 30's.
As the book was written in 1960, I imagine it may have had an impact on overturning some of the deeply instilled racist feelings which still existed at the time in the Deep South.
The rabid dog is potentially a deadly, dangerous menace to the town, and its presence frightens everyone in the community, black or white.
Jem was shocked and surprised to see his father take total control over the situation and had to rethink his perception of father's capabilities.