Not to hijack this thread, but I’m curious as to what these (perceived) differences are. IME, Asians are no more or less uncouth in public than non-Asians.
(On the other hand, one thing that’s definitely different about Chinese dining vs. Western dining is that Chinese dining is guaranteed to be noisy. Ain’t no such thing as “a quiet dinner” in an authentic Chinese restaurant… 
)
To be brief and not commit said hijacking:
Disregard for personal space. Lack of eye contact and nonverbal cues for acknowlegement of presense, proximity, much less for communication of intent. Omission of courtesy speech such as “excuse me” or “sorry” in the event of inadvertent contact.
I’ve read that the Japanese commuters dislike “gaijin” travelers in their midst because they somehow mess up the group cohesion, and impede the efficiency of the flow. Consider this the western counterpart.
And it extends to the roadways… but I promised myself I wouldn’t go there. ;j
If you want to discuss this further, start a new thread in IMHO and I’ll find it.
Aside from the lack of eye contact, I can’t say I’ve seen a pattern of such behavior myself. But hey, different sample pools and all that.