Race - How does it affect a person's identity?

I think for people, your race and heritage tells you where you belong almost. It helps you feel like you should know where you fit in and who you should hang out with and such. Personally, though I don't think it should matter because it doesn't define you. Your personality should define you, not your skin tone. Yet, for James because he is mixed and is black while having a white mother he is uncertain of where he fits in or belongs. He is uncertain of who he can hang out with or what in his eyes is socially acceptable or not. I think his biggest struggle is trying to figure out who he is due to being mixed.  The thing I don't understand about this and maybe if I was mixed I would, I don't know, but why doesn't he base himself and who he fits in with and who he wants to be based on his personality not his family, or his skin tone, or his heritage because those aren't him. He is who he wants and chooses to be, and while he can't change his skin tone, it shouldn't become his identity.