How does Hosseini provide certain evidence of a transformation in Amir during dinner with the general? What are the implications of this change in Amir?

In Chapter 25, Amir asserts his independence and stands up for himself.... as a man. The General's words are harsh, and as readers, we know that only months before, Amir would have been ashamed. He is no longer ashamed, thus when General Taheri interrupts dinner to say, "People will ask. They will want to know why there is a Hazara boy living with our daughter. What do I tell them?" Amir communicated his anger and tells the general that Sohrab was the son of his illegitimate half-brother. He also stood up for Sohrab the way he should have stood up for Hassan, telling the General to never call Sohrab a "Hazara boy" in front of him again.