In To Kill a Mockingbird, what do Scout and Jem learn from Tom Robinson's trial? How does it benefit them? How does it change them?

andlearn that while there are
a lot of racists in Maycomb, not everyone is racist.  They also learn that people are
complicated but generally have good intentions.

Before the
trial,expressed concern to his brother Jack about how the trial would affect Scout and Jem.  He
knew that they would hear a lot of talk, about him and about the trial.  His children would have
to mature a little early.  A rape trial is a very grown-up thing.

You know whats going to happen as well as I do, Jack, and I hope and pray I can get Jem
and Scout through it without bitterness, and most of all, without catching Maycombs usual
disease. Why reasonable people go stark raving mad when anything involving a Negro comes up, is
something I dont pretend to understand€¦ (Ch. 9) 

When
the Cunningham mob comes to lynch Tom Robinson, both Scout and Jem intervene.  They learn that
the Cunninghams are not bad people, but they just got carried away. Atticus tells them that most
people are well-intentioned.  This later pans out when Atticus tells them that two Cunninghams
would have hung the jury, because they were open-minded and willing to accept that Robinson was
innocent after hearing the evidence.

Scout and Jem do not become racists,
despite Scout using the N-word.  She is just repeating what others said.  Jem certainly is no
racist.  He strongly believes that Tom Robinson will be acquitted.  However, another thing that
Scout and Jem learn is that the world is not always fair.  Even with Atticuss evidence that Tom
Robinson could not have caused Mayellas injuries, he is convicted. 

Scout and
Jem also learn that race relations in Maycomb or more complicated than they thought.  During the
trial, they meet Dolphus Raymond, who pretends to be drunk all of the time because he is living
with a black woman and they have children.  Maycomb tolerates him because he is from a wealthy
family. 

In a reflection that shows her growing understanding of the world,
Scout realizes that Maycomb's reaction to Mayellas relationship with Tom Robinson is different
than Dolphus Raymonds with his wife because Mayella is poor. 

She couldnt live like Mr. Dolphus Raymond, who preferred the company of Negroes,
because she didnt own a riverbank and she wasnt from a fine old family. Nobody said, Thats
just their way, about the Ewells. Maycomb gave them Christmas baskets, welfare money, and the
back of its hand. (Ch. 19) 

Jem determines that there are
four kinds of people in Maycomb.  Normal people like the Finches, the Cunningham types, the
Ewell types, and the Negroes.  This is the understanding of race and class relations he has
developed from the trial.