I think that the way in which the novel shows how individuals are shaped by their cultural heritage can be seen through Changez. At the outset of the novel, Changez is an individual who is able to transcend culture. He comes to America, does what he can to shed his own cultural identity and immerse himself in the culture that will be responsible for him accomplishing his own vision of the American Dream. Culture is avoided and is something that he shows himself skilled at being able to transcend. Even when people say things or insinuate items that are culturally offensive, he seeks to put them off to the side and not let them interfere with his pursuit that is largely devoid of cultural reality.
The attacks of September 11 demonstrate so compelling and so horrifically powerful that Changez is no longer able to avoid defining himself in cultural terms. Changez might suggest that it is in times of extreme crisis where cultural refuge is taken in the hopes of providing some structure in a setting that is devoid of it. In his mind, America reverted to a culture of nostalgia in targeting nations like Afghanistan and Pakistan. Changez felt that America's "nostalgia" is what enabled it to view the world being shaped through its own cultural notion of identity. Changez experiences this in reverting to his own cultural identity as he perceives America reverting to its own. In this, Hamid makes clear that the war on terror has constructed binary cultural oppositions that enable individuals to retreat to it as opposed to embracing the more difficult path of trying to understand "the other." In the response of both sides that follow the attacks of September 11, there is a clear embrace of how cultural identity enables individuals to perceive the world and their place in it.