Amir is also seen as a child in need of love, this is shown by the number of times Amir tries to win back his fathers love by coming up with various schemes to get his father to love him, this is shown by Amir getting Hassan to fly his kite for him in the kite running tournament, the only reason Amir gets Hassan to do this is to attempt to win back his fathers love and to make Baba see him as the child he really wanted.
Hassan, unlike Amir, is a selfless and joy-filled character. As Amir says, "Hassan never denied me anything," and we watch Hassan again and again think of others before himself. Hassan covers for Amir when they get in trouble. He defends Amir when the neighborhood bullies threaten them. The boy also serves Amir and Baba with the thoughtless goodwill of a saint. Hassan gets even more saintly. When Amir betrays Hassan in the alleyway, Hassan looks up with resignation. Amir describes his expression as "the look of the lamb". Hassan's ability to suffer without becoming bitter really separates Amir and Hassan. Even years later, after being driven out of the house by Amir and losing his father to a land mine, Hassan writes letters to Amir filled with warmth and nostalgia for their time in Kabul. Somehow, Hassan never thinks to hold a grudge against Amir. It's unthinkable – it's simply not part of the makeup of this character.
Maybe Hosseini has portrayed Hassan in this way to make us believe that he is the child and has had the life that Amir should have been. Although this could be true Hassan also enrages Amir by never betraying him and being as “loyal as a dog”, this is shown when Assef threatens Hassan to give him the kite he cut down in the competition, and Hassan refuses to say that it is Amir’s kite, and this overall leads to Hassans rape, and never throughout this ordeal does Hassan question his loyalty to Amir.
Hassan and Amir are both portrayed as being brothers, they are seen as this because they have both lived and played with each other for the whole of their lives. It is even said that Hassan and Amir have fed from the “same breast”, this shows that the two have a primal relationship with eachother, and it is like they could even be related through blood.
Also as Hassan is Ali’s son and Amir is Baba’s son, Amir and Hassan’s friendship is a binary opposite of Baba and Ali’s friendship, this is because even Baba and Ali were like brothers just the same as Amir and Hassan. Also in these two friendships the father and sons are in correlating roles of the friendship, Baba and Amir both take the lead role with most power in the relationship leaving, Hassan and Ali to take up the role as the loyal friend, because both these relationships are as similar as eachother, this might represent that Baba may have betrayed Ali the same way as Amir betrayed Hassan.
Hosseini portrays Hassan and Amir in very different ways, first he shows Hassan to be the loyal friendly happy child who is always respectful to his leader, and one who would never betray the closest of friends. Hosseini portrays Amir as a child who is jealous, spiteful, weak and pathetic, this is because of the betrayal of Hassan by Amir, and that he is prepared to do anything to get what he wants, in this case his fathers love. But despite all of this Hosseini still portrays the two characters as two brothers separated by class and power, as binary opposites of what their fathers once were and we are led to think that something may have happened between Ali and Baba because of these very close similarities.