Throughout the book, the author explores the idea that children can be capable of great cruelty. This theme is brought to the fore as the main characters slowly escalate their bullying of Linda. The novel juxtaposes childhood innocence with the brutality of bullying to communicate how children manage to escalate situations when left to themselves.

The book regularly alternates between scenes of classic childhood experiences while Jill is at home and scenes of brutal bullying while Jill is trick-or-treating or at school. This juxtaposition reminds the reader that the characters are children while they commit these acts of abuse. What starts as a note passed around class quickly escalates when Mrs. Minish’s watchful eyes are away. Linda doesn’t even know her nickname is Blubber until she gets on the bus, where Wendy involves both the fifth and sixth graders on board in calling Linda Blubber and bullying her. With the bus driver busy driving, “nobody paid any attention” (11) to his threats to quiet them down. Uncontrolled, the kids play keep-away with Linda’s jacket, shoot spitballs at Linda, mock her weight, and create songs about her nickname. By the time Linda needs to get off the bus, Jill can “tell she was close to crying” (11).