There are many ways that you can approach the idea of social hierarchy in The Kite Runner. Here are some ideas for you:
1. Social hierarchy has a great effect on the development of identity in The Kite Runner. Class is closely tied to one's self-worth and subsequent life choices; this is clearly seen in the development of the characters Amir and Hassan.
2. One's class heavily influences one's outlook on life. Oftentimes, class gives people either a sense of control and agency or the feeling of always being at the whim of others. The Kite Runner highlights the ways in which class shapes one's view of life.
3. Class is highly rigid and violently enforced in The Kite Runner. However, characters often figure out how to subvert the structure of social hierarchy in ways that show a commonality between all people, regardless of class.
What is important is to think about how you feel class and hierarchy shapes the characters of the novel. Do you think their class is a defining feature of who they are? Do you think that class is not important when it comes to their relationships, or do their relationships exist as they are because of class?