Arnold starts The Absolutely True Diary of a Part-Time Indian feeling like the reservation outcast, but once he transfers to the fancy white school in Reardan, he becomes a basketball star who gets carried around on people's shoulders. How does Arnold go from zero to hero?
Well, the journey to a new identity is not an easy one for Arnold, trust us.
When Arnold transfers to Reardan, he sees himself as having two different selves: Junior from the outcast from the reservation and Arnold from the white high-school at Reardan. The rest of the novel is really all about reconciling these two different selves.
So how does he do it?
Well, Arnold learns to see himself not simply as Junior the Indian or Arnold the traitor, but as someone who belongs to many different tribes (24.31-24.44). He becomes a multi-tribal kind of guy. He moves between locations, kind of like a "nomad" (30.182). By seeing himself in this way, Arnold resolves his split personality crisis and finds a meaningful, less restrictive form of identity.
Our environment can define who we are. By changing our environment, we can change ourselves.
By seeing himself as a member of many different tribes, Arnold is able to forge a new and meaningful identity. He becomes multi-tribal, which means that he belongs to many different groups.
Arnold is a nomad, just like the old time Indians. Even though he leaves his home on the reservation, he's not abandoning his family, history, or identity as a Native American.