"That Hassan would grow up illiterate"

In Afghanistan there is a strict class system. Hassan is a Hazara while Amir is a Pashtun.  Hazaras are mistreated in society and work as servants or another job that does not require education. This means that Amir can receive a full education while Hassan who is a Hazara cannot. Therefore this is why Hassan will be illiterate and not get to go to school with Amir.