How does Harper Lee show Scout and Jem learning about racism?

Comprising the main portion of the book's examination of racism and its effects are the underlying themes of prejudice vs. tolerance: how people feel about and respond to differences in others. At one end of the spectrum are people who fear and hate, such as the members of the jury who convict an innocent man of rape because of his race. Atticus and Calpurnia, on the other hand, show understanding and sympathy towards those who might be different or less fortunate. When Scout brings a poor classmate home for dinner and then belittles his table manners, for instance, Calpurnia scolds her for remarking upon them and tells her she is bound to treat all guests with respect no matter what their social station. Atticus similarly bases his opinions of people on their behavior and not their background. Unlike Alexandra, who calls poor people like the Cunninghams "trash" because of their social station, Atticus tells his children that any white man who takes advantage of a black man's ignorance is "trash."