,they call it culture different.You might be very sensitive, and your boss might be hot-temper or arrogant. Your boss and the american fellow can talk about jokes, sport, wine, politics, etc while discussing research topic, can you be part of it?
If I were you, I would leave this group as soon as possible.
Don't worry, because
天生我才必有用,千金散盡還複來
Not to mention a paper