Yes, I believe there is some truth to that. Since China shares borders with many countries, people living near those borders often have cultural similarities with neighboring countries. It's often mentioned that people in the central mountainous regions are friendlier than those on the coast, possibly because life is harder there and they need to work together more. The environment definitely influences people's personalities, especially in a large country like China.

Not really, I don't think there's a huge difference in personalities across different regions in China. Generally, people everywhere have similar attitudes and behaviors. Plus, culturally, we Chinese share many common values and traditions, which kind of brings a sense of uniformity in how we act and think, regardless of where we are from.