What are Jem Finch's personality traits in To Kill a MockingBird, and how does he show these traits?

The personalities of Jem and Scout are actually very
similar in To Kill a Mockingbird. Jem shows a hot
temper on more than one occasion in the novel (though he is
not as quick-tempered as Scout). He destroys Mrs. Dubose's camellias after she insults
Atticus, and he becomes very angry after the guilty verdict is revealed in the Tom
Robinson trial. Jem is very sensitive--much more so than
Scout. He shows this side when he finds out that Nathan Radley has lied to him about
cementing the knothole, and he shows them again after Mrs. Dubose's death. He also shows
his heroism when he stands by Atticus at the jail in the
face of the lynch mob, and he tries to fight off Bob Ewell to save his sister after the
Halloween pageant. He is also a bit of an introvert, since
he has few (if any) close friends, and he loves to read. He also loves
sports (there are many sports references in the novel) and
he goes out for the football year his first year of high school.