We tend to think of jealousy as something that has free reign in kids and teens but that tapers off when we grow up and get all mature and stuff. The Interestings is here to make it crystal that that this is so not the case. Jealousy runs rampant in the novel, mostly in the form of the main character, Jules, and it seems to actually get worse when she becomes an adult. As she gets older, she covets the lives and things of others more. Her life and relationships are governed by jealousy, so much so that the book almost treats it like it's inevitable.
Questions About Jealousy
Jules doesn't seem to be jealous equally—why might she be more jealous of Ash than Ethan, when Ethan is the successful one?
Why don't we don't really see jealousy in the second generation (i.e. Mo, Rory, Larkin)? Do we see it in the Interestings' parents? What does this tell us about jealousy's legacy?
Is jealousy really inevitable when friends have different levels of success, like the book sort of hints?
Chew on This
Jules's jealousy is tied so tightly to her love for Ethan and Ash that it almost seems like she thinks her obsession with them should have pulled her across that success gap.
Rory and Larkin are super different but get along without jealousy, so we'd be willing to say that they're the more perfected form of Jules's and Ash's friendship.