In the novel The Watsons Go to Birmingham, how does Byron change throughout the story?

At the beginning of the novel, Byron is so badly behaved that Momma and Dad are pretty worried about him. Kenny describes Byron as "officially a teenage juvenile delinquent" (2). Byron shows a lack of maturity and judgment by doing things like sticking his tongue to the frozen car mirror after hitting Kenny with a snowball that he spits out of his mouth. Byron also enjoys lighting things on fire, and he keeps doing so even though Momma punishes him. She's afraid that he is going to burn down the house. Things get so bad that Momma and Dad decide to bring Byron to his grandmother's house in Birmingham, Alabama.
By the end of the novel, however, Byron has matured and begins to take on more responsibility. First, he saves Kenny when Kenny almost drowns in what he calls a "Wool Pooh" near Birmingham. Then, after Kenny is traumatized by having seen the Birmingham church bombing, in which four African American girls are killed, Byron is able to talk Kenny out of his funk, and Byron helps Kenny feel safe again. Byron becomes capable of showing caring and sensitivity toward others by the end of the novel.