Why does Atticus say Scout should ignore Jem in the treehouse?
Jem and Scout's relationship is at the verge of shifting as the story opens. As a 9 or 10 year old, Jem is leaving/has left behind the ways of young childhood and his focus in life is changing. As the story progresses, Jem begins to distance himself somewhat from Scout, which she senses, but does not seem to understand. In short, Jem is growing up;Scout doesn't understand his pre-pubescent moodiness and the distance she perceives as growing between them. Atticus simply tells Scout to ignore him because Atticus understands the changes that Jem is going through.