In Divergent book, characters do not really change, but show more about themselves as you get to know them. We can´t really tell if many charactes change through time, due to the lack of knowledge we have about their past (obviously not mentioned in the book.)
Characters such as Four start revealing more about himself, as Tris (narrator) gets to know him better. In my Opinion, Tris is the only character, who we can tell that has changed as time passes. This is beacause Tris is the protagonist and also the narrator of this story. That's why we are mostly connected to her, and we can see how her personality, actions, and feelings change. Tris started as a confused girl insecure about herself, and she end up being on of the bravest and strongest characters.
Characters such as Four start revealing more about himself, as Tris (narrator) gets to know him better. In my Opinion, Tris is the only character, who we can tell that has changed as time passes. This is beacause Tris is the protagonist and also the narrator of this story. That's why we are mostly connected to her, and we can see how her personality, actions, and feelings change. Tris started as a confused girl insecure about herself, and she end up being on of the bravest and strongest characters.