“Jem thought about it for three days. I suppose he loved honor more than his head, for Dill wore him down easily” (Lee 16).
When Scout says this she is proving the fact that Jem is so incredibly immature that he would do anything (lose his head) and go the greatest extent just to prove a point... That he is not scared. In the beginning of the story Jem is seen as someone that can get swayed very easily, and he constantly wants to prove his importance to his friends. Having to constantly prove this to someone is a trait of a child, meaning that Jem still has a little boy mindset at this point in the story.
“Jem seemed to have little fear of Boo Radley now that Walter and I walked beside him. Indeed, Jem grew boastful" (Lee 31).
As Jem progresses throughout chapters 1 through 3 the the reader can see that his confidence begins to grow higher and higher as his age grows. This quote shows that because he was surrounded by friends he is comfortable with his confidence or the scared trait he once had within himself vanishes. Through this interaction with his friends, Jem begins to discover this newfound confidence in himself he never knew he had. He is overall becoming more self aware as he matures into a young adult.
“Jem was not one to dwell on past defeats: it seemed the only message he got from Atticus was insight into the art of cross examination” (Lee 68).
Through saying "insight" it proves that Jem himself is beginning to listen to Atticus' main example that he sets for his children. To not judge someone until you see things from their perspective. Overall showing that he is mentally growing as a person, and learning the fundamentals of never judging a person on their actions or outward appearance. Here Jem begins to view adult figures as something of importance, and that he should take their morals and examples into consideration with his everyday life.
“ ‘That’s because you can’t hold something in your mind but a little while,’ said Jem. ‘It’s different with grown folks' His maddening superiority was unbearable these days. He didn’t want to do anything but read and go off by himself” (Lee 184).
As Jem grows older and the chapters of the story go on more differences between Scout and Jem are made present. Scout begins to come to the realization that her brother feels that he is superior towards her and won't treat her as just a “friend” anymore. He will start to play his protective brotherly role in her life. And, while this may be hard for Scout to wrap her head around she understands that her brother is maturing and turning into a young adult, and that he would much rather do grown-up activities such as, reading, instead of playing childish games with his little sister.