Why does Cambodian border inspection only accept tips from China people?

According to our observation, border inspectors only ask China people to tip, while Japanese and Americans who have passed the customs successively do not ask for tips. I want to know what China people are like in the eyes of border inspectors.

Experience: You can pretend to tip when you stamp the border. When he relaxes his vigilance and puts the stamped passport where you can get it, he can quickly pick up his passport and leave. It's basically useless to play dumb. They are thick-skinned and will ask you directly.

I don't care about money, but I really don't want to encourage their corruption. Moreover, every time you tip, the image of China people will probably continue to decline by one degree. The image of China people is mostly caused by their own actions.

Speaking of tipping, by the way, Cambodia does have a tradition of tipping. Hotels, motorcycle drivers, tour guides, etc. Everyone needs a tip. Amount 1000 riel (about RMB 2 yuan).