Jem realises, in the novel, the amount of segregation and racism in Maycomb County, he says that there are 4 kinda of folk, the ordinary like us, the neighbours, the Cunninghams, the Ewels and the black people.

After the trial he cries and this shows that he understands what is happening and how wrong the white people are. As he speaks to Scout we can see that he is maturing and has grown an understanding of the world and society around him and due to his father, Atticus, he is also able to know what is right and stand up for it.
In the novel we see this when he says “it’s not right”. This short quotation indicates his maturity and how much he’s grown.