I think the problem comes from when you say "they expect them to act white." Why? Because of something I was rambling about- there's a matter of identity. It's the key to... well, everything. Skin color, gender, sexual preference, religion, language, nationality, anything and everything. It's a matter of accepting there are differences and not looking down on someone for them, as opposed to expecting someone to abandon that identity in order to fit in.

The moment you expect someone to conform to your identity or else be shunned is the moment it all goes pear-shaped.