Harper Lee's To Kill a Mockingbird and John Steinbeck's Of Mice and Men both concentrate on the treatment of disenfranchised parts of society, members of the community who have less power and respect than others. The plots of both books concentrate on the inhumane treatment of people who are weak or different and therefore largely misunderstood.
For example, in To Kill a Mockingbird, Scout and Jem come to realize that Boo Radley, long thought to be scary in the community because he is a bit mentally disabled, is actually a decent, honest man who saves Jem's life at the end of the novel. As Atticus tells Scout and Jem in Chapter 10, "remember it's a sin to kill a mockingbird." A mockingbird is a symbol of a weak, defenseless creature because all the bird does is sing. One should not harm it, Atticus says, because it is defenseless. In addition, Tom Robinson, the African-American man who Atticus defends, is like a mockingbird because he too is innocent and defenseless but is facing great persecution and violence because of his race.
In Of Mice and Men, weak and defenseless characters such as Lennie are also treated with cruelty. Lennie is a developmentally disabled man who is often misunderstood because he combines innocence and mental slowness with great physical strength. In the end, his friend George shoots him out of mercy because a mob is after Lennie. Again, the plot of this novel is about how weak or defenseless people are targeted in society because they are misunderstood. Both authors emphasize the inhumanity of this type of treatment.