How Jem Finch display immaturity throughout the novel?

Jem Finch displays immaturity particularly towards the beginning of the novel. When Scout begins telling the story, Jem is only ten years old. As a ten-year-old boy, Jem displays immaturity by believing and spreading the rumors that surround their reclusive neighbor, Boo Radley. Jem is infatuated with the idea that a monstrous being lives next door. He does not hesitate to discuss with Walter Cunningham Jr., Dill, and Scout how Boo Radley is a grotesque malevolent being. He even recreates the false legends about Boo in a game the children name "One Man's Family." Jem also invades the Radley's privacy by sneaking into their yard and peeking through their window. Jem also shows immaturity by losing his temper and ridiculing his younger sister for being a "girl." However, Jem matures into an empathetic, respectful individual as the novel progresses.