While they are still living in Afghanistan, Baba shows great disappointment in his son. Aside from Amir's literary pursuits, which Baba frowns upon, Baba has noticed that Hassan has had to defend Amir from the taunts and threats of other boys. Baba rightly perceives this as a weakness on Amir's part, and his son's lack of interest in sports and other physical endeavors further infuriates him. Baba finally has a reason to be proud when Amir wins the kite flying contest, but that soon changes when Amir asks his father to consider dismissing Ali and Hassan from the house. When Amir firmly rejects Amir's request, Amir shamefully plants his own birthday presents under Hassan's mattress in order to disgrace Hassan.
Things change for the better once Baba and Amir flee to America. Baba's own social and political power has been shattered, and Amir slowly grows into a mature adult, graduating from college and achieving his goal of being a published writer. Amir marries a woman he loves, instilling further pride in Baba; and upon Baba's death, the two have become closer than they ever have.
At the beginning of the novel, Baba seemed to be ashamed with his son, Amir. His disappointment can be due to his son's hobbies, such as reading and writing stories. Baba didn't want this nonsense. Baba was a strong, well known and respected man who is more of a outdoor and sporty sort of character. Whereas Amir, is what I believe is an embarassment for Baba to have such a weak son. Baba didn't want this, he wanted a son who was just like him, someone who played sports like soccer, being able to stand up for themselves and someone who would make Baba himself, proud. As a secret, Baba honestly feels guilty and ashamed for what he has done in the past.
But, as the story develops and goes on, Baba's feelings for his son Amir becomes from a strain relationship to a strong father and son relationship.