The Outsiders fits into a genre of young adult fiction and is often called a "coming-of-age" novel. Generally, a coming-of-age story is one in which events lead the main characters (protagonists) to experience psychological or moral growth that takes them from childhood toward emotional maturity.
What genre would you consider the book, The Outsiders?
Character change is very important in a coming-of-age story. In The Outsiders, Darry characterizes Ponyboy as lacking common sense. Ponyboy agrees with his older brother, admitting that he is smart at school but sometimes he just doesn't think. These occasions get Pony into trouble that he could avoid. This is one aspect of Ponyboy's character that evolves throughout the book — he learns that his behavior impacts others.
As Ponyboy narrates the novel, the reader sees the changes in Pony's viewpoints as he deals with many issues that are common in an adolescent's life. The most powerful issue is that life is not always fair. From the deaths of his parents, to the economic conditions that cast them as "greasers," to the deaths of his friends, life is not fair to Ponyboy.
During the two weeks in which the novel takes place, Pony sees three deaths — two greasers and one from the rival gang, the Socs — the "West-side rich kids." By realizing that death at a young age is equally unfair for all of them, Pony is able to not only survive, but to justify his own existence. He takes it upon himself to make all of their deaths mean something; thus, his "coming-of-age."