As the trophy of the kite-flying tournament, the kite can explain the unique characteristics of each individual in relation to itself, so its symbol takes on a dual meaning--one for Amir and one for Hassan. For instance Amir, especially as a child, is perpetually in pursuit of Baba’s affections.
Without a mother, Amir only has Baba to look up to as a role model and so it is his sole mission to gain recognition from Baba, who seemingly has too many expectations from a mere child. Thus, to Amir the kite symbolizes the key to winning Baba’s heart.
On the other hand, the kite to Hassan symbolizes the friendship and loyalty he feels towards Amir. Therefore, when confronted by Assef and his gang in the alleyway, he fears losing the kite to Assef would jeopardize that friendship and so submits to Assef’s brutality.
Evidently, the motives behind both Amir and Hassan’s decisions are meant to achieve the opposite ends. This discrepancy represents the difference between two general people: the selfish and the righteous.