How are mockingbirds used as symbols and motifs in To Kill a Mockingbird?
For example, comparing Boo and Tom to mockingbirds - can this idea be developed? Like saying that they're 'christ-like' figures as they suffer for the sins of others.
It is Miss Maudie who affirms that it is a sin to kill a mockingbird, since "they don't do one thing but sing their hearts out for us."
The mockingbird, as a metaphor, is used to convey two meanings in particular, the first of which is a moral and the second of which is a social reality.
The moral sentiment behind the idea of a mockingbird can be taken directly from Miss Maudie's statement. Mockingbirds are figures of innocence and beauty. They share the world, or, perhaps more importantly the neighborhood, with Scout and Jem and should be treated with admiration. They should be protected or at least left alone.
Tom Robinson and Boo Radley match this metaphor and this moral in that they each do good deeds yet find punishment instead of admiration. Tom helps Mayella Ewell with chores that no one else is willing to help her with and he refuses payment. Boo shares trinkets with Scout and Jem and later saves their lives.
Atticus attempts to offer some protection to both these men, recognizing them as "mockingbirds" and following the moral message of the metaphor. However, the majority of the town views the men differently. This is the second, social meaning of the metaphor.
Mockingbirds need to be protected from Jem and Scout by Atticus' mandate because, without this instruction, Jem and Scout would not have known better. They would not have given the proper admiration to these figures.
Similarly, the town treats Boo Radley as a personage to be dragged through the proverbial rumor mill and treats Tom Robinson without any respect at all. These men are persecuted - to varying degrees - because the town does not "know better".
Due to the nature of society, mockingbirds, in their innocence, are subject to injustice. Scout realizes this as she matures through the novel, articulating her point of view at the novel's close.
Scout tells her father that revealing Boo Radley's role in Bob Ewell's death would be "like shootin' a mockingbird."
In answering this question, you need to think about what Atticus says to the children about mockingbirds...."never shoot a mockingbird....they do nothing but sing for us." Apply that quote to the lives of Boo and Tom. What have they ACTUALLY done to deserve the punishment received (Boo's treatment by the town of Maycomb and Tom's "guilt" simply because of the color of his skin).