Amir and Hassan
Rather than discussing Amir and Hassan separately, I will analyze them together since their characters complement each other.
From the onset, Amir and Hassan do not share a complete and balanced friendship, as Amir does not behave as a true friend to Hassan. He does not understand why Baba likes Hassan so much, considering he is only a Hazara servant. Also, Amir overhears Baba saying that Amir can not stand up for himself and that Hassan has to protect him. Therefore, Amir feels obliged to prove himself to his father in order to gain his affections.
Amir’s love for Hassan is selfish as he exploits him for his own purposes. For instance, in the kite flying tournament, Amir uses Hassan to run the kite for him. In addition, Amir has too much pride. He does not want to believe that Hassan is a better person than himself. Amir is a wealthy Pashtun, whereas Hassan is a poor Hazara; Amir is educated whereas Hassan isn’t. Yet, Hassan is a true friend to Amir, because he holds no bad intentions or feelings for him. His love for Amir is selfless. He is loyal and honest. So why are they friends?
Amir enjoys the control he has over Hassan, while Hassan has only pure intentions. If it wasn’t for Hassan’s purity, there would be no friendship. Hassan is unaware of Amir's jealousy and exploitive behaviour, and simply goes on being a friend to him. Moreover, although Amir enjoys having control, there is a part of him that is pure. He is only a child, and thus holds some innocence. This is why at times he treats Hassan as a true friend, such as when he engraves their names on the pomegranate tree. He lies in the middle of the spectrum, between Hassan’s purity, and Assef’s evil. Amir represents a realistic person, such as us, who is flawed.