In To Kill a Mockingbird, who is Francis, what's he like, and why did Scout get in trouble?

Francis is Aunt Alexandra's grandson. We see his character introduced in Chapter 9, when Jem, Atticus and Scout attend Christmas dinner at Aunt Alexandra's. Scout and Francis are a year apart in age and do not get along at all. Francis first gets Scout going when he says this about her friend Dill:"You mean that little runt... Grandma says he hasn't got a home...he just gets passed from relative to relative...You're mighty dumb sometimes, Jean Louise." Francis is merely repeating what he hears his mother saying about the people that Atticus and his family surround themselves with. He continues with, " Guess you don't know any better though...I guess it ain't your fault if Uncle Atticus is a n-lover..." Francis continues his taunts and Scout's temper explodes. It is here that she gives him what he had coming-a good swift punch to the face. Scout, of course, gets blamed for saying things she didn't say and is then later punished by her Uncle Jack.