I'm a professional working in an ethnically diverse workplace. We hired a Chinese American contract worker. The first thing he did was to attach himself to the sole white man in the department, with whom he had no work relations. He would follow him everywhere like a "Fart-following worm" (as the Chinese expression goes) When other Chinese greeted him, he would ignore them. I would stand in his path, look him in the eye and raise my voice to say hello in order to get a reluctant greeting in return. Although he is a first generation Taiwanese immigrant, he would never be caught dead speaking Chinese. The only Asians he would grace with his company were Japanese who were friends with the white guy.
This kid couldn't even walk with his shoulders up. I don't think he feels very good about himself as an Asian. He's always letting the white guy take the lead. Although he is a U.S. citizen, he is not an American-born Chinese. He immigrated with his family at a young age. In my experience, it is more often the naturalized U.S. citizens who take a negative view of other (newer) immigrants sharing their ethnic background. The American-born Chinese, secure in their American identity, generally do not feel the need to dissociate themselves from immigrants in order to "fit in better" with the "mainstream".