
The last thing a foreign student need is to start a fight or lose the respect of their peers through some apparently harmless action. While people tend to be at least a little tolerant of foreigners’ strange ways, abusing this privilege too often or after you’ve been told about local customs, is asking for trouble.
Under no circumstances, it is a good idea to expect the rest of the world to adapt to you and follow those sophisticated, civilized patterns that seem normal to your perspective. Different cultures aren’t inherently worse or better than one another, so the “when in Rome” principle applies.