How does Jem develop empathy and tolerance when he witnesses the Tom Robinson trial in Harper Lee's To Kill a Mockingbird?

In Harper Lee's To Kill a Mockingbird, at first, witnessing Tom Robinson's trial, especially hearing the verdict after seeing that all of the evidence points to Robinson's innocence, only serves to make Jem bitterly angry, angry to the point of tears. However, as he continues to work through his feelings, Jem develops a better understanding of people that shows he has developed a sense of empathy and tolerance. Jem's sense of empathy and tolerance can especially be seen towards the end of Chapter 23.

In Chapter 23, Scout's announcement that she plans to invite her schoolmate Walter Cunningham home for lunch once school starts up draws some very bitter comments from her Aunt Alexandra. Aunt Alexandra denies Scout permission to invite Walter home, saying that the Cunninghams are "not our kind of folks" and even going so far as to call Walter "trash." Aunt Alexandra's comments make Scout so angry that she wants to attack her aunt and bursts into tears. Jem takes his sister into his care and tries to console her. While consoling her, Jem explains some new revelations he has acquired about people.

As he explains to Scout, when he was younger, Jem used to think the same thing as Scout--that all people were the same. However, witnessing the prejudice that caused an innocent man to be convicted and sentenced to death has led Jem to try and develop some new conclusions about people. As Jem explains to Scout, he has become forced to ask himself the question, "If [people] are all alike, why do they go out of their way to despise each other?" (Ch. 23). Jem further explains to Scout that people in different social classes have different education levels, and it's lack of education that breeds hatred.

Seeing that all people have differences in education allows Jem to look compassionately at all people--he sees that they cannot help what they do due to their education levels. For this reason, he is even able to view his aunt with compassion and empathize with her disdain for others. He empathizes with her because he agrees that the Finches are, luckily, more educated than people like the Cunninghams and the Ewells, and that education level places the Finches in a greater, more important position in society. Yet, Jem also sees his aunt as being less educated than Atticus; therefore, he understands why his aunt is able to show less tolerance of others than Atticus--she can't help it. Hence, because Jem has developed this newfound understanding that people cannot always help what they do due to education levels, he is able hear his aunt speak negatively of others without being angered, whereas Scout is still very much angered by it. His ability to hear his aunt speak out against people shows he has developed a sense of compassion and empathy he is able to extend to even his aunt.