My school and my department has a lot of undergraduate students from China. When I took this instructor's class, he routinely
pressured the foreign students to answer questions about their home country that they weren't comfortable answering. (This is a math department; his questions weren't relevant to the course.)
pressured the foreign students to quickly answer when they struggled to either understand him or respond in English.
sneered when they answered one his questions wrong, no matter how strange the question was.
didn't accept "I don't know" from Chinese students.
He never did this to any of the domestic students. This was a topic of discussion among the American students before his class—we all noticed it. Several Chinese students dropped his class because of the way he treated them, but they didn't complain because that isn't considered kosher in China. (He actually said, "I don't understand why 'A' students are dropping," after a very talented Chinese student withdrew from this class.)
I can't point to any one thing he said or did that clearly crosses the line—I would have reported him to the dean's office and the department chair if he had—but he came up to it too many times for me to be comfortable with his behavior. I liked the guy in the beginning of the course, but I was sick of the way he treated my Chinese friends by the end.
To summarize: I feel this adjunct's behavior towards Chinese students borders on harassment, but isn't obviously harassment. Should I do anything? What?
To clarify—this class already ended, but I'm told he still keeps up this crappy behavior. And the Chinese students actually come from mainland China.