One of the more peculiar practices in American and other Western cultures is the custom ironclad rule of tipping in certain individual consumer level transactions. Despite being “voluntary,” the consequences of not tipping at all or even just tipping below what is considered acceptable would probably lead you to receiving poor service in the future or an irate waiter running after you as you leave.
Tipping in this sense is definitely not standard in China, but to put it into the Chinese context, it’s best to think of it as the red envelopes stuffed with money (hong bao) that you are expected to pay government officials or your doctor/surgeon to simply do their jobs. JiaYou would probably take issue with this, but I think it’s actually quite similar.
One of the more subtle differences between New York and Shanghai (which can be generalized to Western and Asian societies overall) is the relationship between motorists and pedestrians.
In the U.S., pedestrians are treated as the equivalent of an endangered species. They are to be protected at all costs (admittedly, this is probably related to being a highly litigious society), and at times coddled (which is very much the case on the West Coast). In fact, in many East Coast cities, such as NY and Boston, pedestrians can even have an arrogant demeanor, assuming right of way without regard to their physical safely. If you honk at them when they are not walking with the light, they’ll actually glare at you and act indignant!