The central character of the story as well as its narrator, Amir has a privileged upbringing. His father, Baba, is rich by Afghan standards, and as a result, Amir grows up accustomed to having what he wants. The only thing he feels deprived of is a deep emotional connection with Baba, which he blames on himself. He thinks Baba wishes Amir were more like him, and that Baba holds him responsible for killing his mother, who died during his birth. Amir, consequently, behaves jealously toward anyone receiving Baba’s affection. His relationship with Hassan only exacerbates this. Though Hassan is Amir’s best friend, Amir feels that Hassan, a Hazara servant, is beneath him. When Hassan receives Baba’s attention, Amir tries to assert himself by passive-aggressively attacking Hassan. He mocks Hassan’s ignorance, for instance, or plays tricks on him. At the same time, Amir never learns to assert himself against anyone else because Hassan always defends him. All of these factors play into his cowardice in sacrificing Hassan, his only competition for Baba’s love, in order to get the blue kite, which he thinks will bring him Baba’s approval.
The change in Amir’s character we see in the novel centers on his growth from a selfish child to a selfless adult. After allowing Hassan to be raped, Amir is not any happier. On the contrary, his guilt is relentless, and he recognizes his selfishness cost him his happiness rather than increasing it. Once Amir has married and established a career, only two things prevent his complete happiness: his guilt and his inability to have a child with Soraya. Sohrab, who acts as a substitute for Hassan to Amir, actually becomes a solution to both problems. Amir describes Sohrab as looking like a sacrificial lamb during his confrontation with Assef, but it is actually himself that Amir courageously sacrifices. In doing this, as Hassan once did for him, Amir redeems himself, which is why he feels relief even as Assef beats him. Amir also comes to see Sohrab as a substitute for the child he and Soraya cannot have, and as a self-sacrificing father figure to Sohrab, Amir assumes the roles of Baba and Hassan.