Scout learns about poverty and about her own privilege when Walter Cunningham visits her house for dinner. Walter didn't bring a lunch to school, and when he is eating at Scout's house, he asks Calpurnia for molasses. When he pours syrup all over his food and then returns the syrup jar to its saucer, the action makes a clattering noise that causes Walter to duck his head. It's clear that he is embarrassed, and he's likely more embarrassed when Scout asks "what the sam hill he was doing." Calpurnia then summons Scout to the kitchen, where she lectures Scout on how to treat company. Scout learns that to Walter, syrup represents an almost unattainable luxury and that Walter lives in poverty. Earlier in the chapter, she says of him, "Walter looked as if he had been raised on fish food: his eyes, as blue as Dill Harris’s, were red-rimmed and watery." Walter clearly survives on very little sustenance, and from his visit to her house, Scout learns that others in Maycomb have far less than she does.
Walter's visit in Chapter 3 provides Scout insight into the lives of lower-class farming families. During dinner, Walter has a discussion about crops with Atticus and mentions that the reason he cannot attend school in the spring is because he needs to help his father with "choppin'." Atticus then elaborates on how America's economic hardship drastically affects farmers in their region. Scout then witnesses Walter pour syrup all over his meal and makes several rude comments. Calpurnia immediately takes Scout into the kitchen and gives her a lesson on manners, respect, and hospitality. Scout not only gains insight into Maycomb's farming community but also learns the importance of treating her guests with respect regardless of their social status. She also learns to keep her negative comments to herself and treat everyone equally.
By eating lunch/supper with Walter, Scout learns about societal differences and acceptance of others. Walter represents the lower class, poverty stricken people of Maycomb. As Aunt Alexandra would have Scout believe, the Cunnigham's are beneath the Finch's; however, through Atticus and Cal, Scout learns that all people are equal regardless of their financial status.