What are some examples of textual evidence that connect to this theme in the novel: "Jealousy has serious consequences if it's allowed to flourish"?
Jealousy seems to be a mix of low self-esteem plus envy; it's mainly about perception from those two weak points of view, too. If a person obsesses over these feelings for too long, there are sure to be negative consequences. In A Separate Peace, Gene compares himself to Finny's accomplishments, which were: first, socially winning over both adults and students (26-27); second, physical athleticism like breaking the school swimming record (44); and finally, creating Blitzball and the Super Suicide Society (39;33). Ironically, Gene realizes that his jealousy was unfounded right before he jounces the tree limb and breaks Finny's leg. It was then too late to stop the unsettled, erroneous, and long-standing emotions from breaking through his sub-conscious which made him act out on impulse. Had Gene been able to think about his realization longer before the tree incident, he may not have broken Finny's leg.