How does Jem become a hero in Scout's eyes in Chapter 4 of Harper Lee's To Kill a Mockingbird?
In Chapter 4, Scout receives quite a fright when she rolls in the tire right up to the Radley's porch. She hears Boo Radley laughing when she gets up to run back to the boys who are also yelling at her to bring the tire back. She does think that Jem is brave to run back and get the tire for her; but she believes he is a hero for a couple of other reasons. First, Jem shows that he is brave by wanting to play out the Radley family drama in their front yard for everyone to see. Of course, Dill gets the villain roles, Scout gets the women's roles, and Jem always gets to play the hero of their stories.
Next, since Scout heard laughter coming from inside the Radley home, she knows that someone is watching them. She doesn't tell this to Jem, but she does protest playing the game by saying, "He can get out at night when we're all asleep" (39). Jem reassures her over and over again that no one will get her at night because they probably killed Boo, anyway, and stuffed him up the chimney. He also tells Scout that no one will get her with him and Calpurnia there to protect her during the day and Atticus can protect her at night. Scout says, "Jem was a born hero" (39). The fact that Jem says that he is one of her protectors shows Scout that he is a hero that she can depend on.
Scout actually encounters many frustrations with Jem during the chapter. After having been rolled to fast in the tire, the tire spits her out in the Radley's yard where she hears something inside that frightens her, but she doesn't tell the boys.
For her to consider Jem heroic, she must have seen evidence of his bravery. This occurs twice earning Jem a new respect in Scout's eyes. First, Jem overcomes his great fear of the Radley's place in order to retrieve the tire. Because Scout feels partially responsible for this, his gesture is even more heroic and brave because it relieves her responsibility.
As the children are playing the Boo Radley game, Jem takes the heat from Atticus and lies to him about the game protecting both Scout and Dill.