Scout develops more understanding of the trial process and empathy for the Ewell and Robinson families during the trial.
In the weeks and months leading up to the trial, Scout learns a lot about the legal process. She does not really understand why her father is defending Tom Robinson, what Robinson is accused of, or why the residents of the town are reacting to her father with such disdain. During the trial, she learns about the roles of race and class.
Scout follows the testimony well, and understands that Mayella had a tough life.
As Tom Robinson gave his testimony, it came to me that Mayella Ewell must have been the loneliest person in the world. She was even lonelier than Boo Radley, who had not been out of the house in twenty-five years. (ch 19)
This demonstrates an understanding of class and empathy. Scout realizes that Mayella, as an Ewell, has certain disadvantages.
Scout also develops an understanding of race as she thinks about Tom Robinson’s life, and the people’s reactions to him. For example, when Tom says he felt sorry for Mayella, Scout realizes that this is a fatal mistake.
The witness realized his mistake and shifted uncomfortably in the chair. But the damage was done. Below us, nobody liked Tom Robinson's answer. (ch 19)