Like the other educator response states, Harlem is portrayed as a place full of temptations. Sonny’s brother, to an extent, consequently sees Harlem as a place that can infect one’s psyche and prevent one from achieving success in life. Sonny’s brother almost resents the problems he sees in Harlem and generally blames people who give in to these temptations rather than blaming the system of cyclical poverty. He views himself as superior to those who weren’t able to resist the temptations and “make it.”

This brings us to Sonny himself, whom his brother sees as the ultimate Harlem failure. Sonny certainly is a drug addict, and perhaps if he had had a more affluent upbringing, he wouldn’t have fallen into addiction. However, I think his biggest vice—if you could call it that—is his love of music. Sonny’s dedication to his dream of becoming a musician forced him to give up a more traditional lifestyle and put him in situations where drugs were readily available. Considering the familial history of addiction, it isn’t surprising that Sonny would become an addict if he just experimented like many others in his social circle likely did.

Overall, Sonny and his brother are both impacted by Harlem’s particular society, and each reflects a different view of it.

This is a complex question. The narrator makes clear that Harlem is a place of darkness, with temptations for any child brought up there, and he notes that the same temptations still exist for the students he teaches.  But Sonny's brother also remembers a support system  when "old folks were talking after the big Sunday dinner" (444) and Sonny knows there is darkness and joy when he says, "All that hatred down there, all that hatred and misery and love" (458). 

Sonny's brother has managed to stay in Harlem and become a "solid citizen" with a teaching career and a family.  He has escaped the temptations of Harlem.  But do you see anything lacking in him?  Does he have any soaring joy in his life? He is not always the most sympathetic figure in the story. His wife is more comfortable talking to Sonny than he is, and there he is often lacking in empathy. He had written his brother out of his life.  He has succeeded in not getting caught up in a life of drugs and crime by holding himself apart, but this makes him a somewhat rigid figure. This is the tradeoff for the narrator.

Sonny, on the other hand, has succumbed to the temptations but in the final scene in the story, the reader can see that he has great depth and that there is great joy as well.  This, too, is a tradeoff, isn't it? In order for Sonny to "fly," he has endured great sorrow, and he talks about a woman singing the street to make his point, saying, "...it struck me all of a sudden how much suffering she must have had to go through - to sing like that" (456).  

As for Sonny's biggest vice, it is clearly his drug addiction, likely an inherited addiction, since we are told that the father had a drinking problem.  If Sonny had been raised on Long Island, would he have become a heroin addict?  Maybe not, but he probably would have become an alcoholic.