be sensitive to other kids

I really think your son's case is too extrem. chinese kids may not be popular ones but seldoms are disliked so much because they are gentle. make sure talk to his teacher, ask for her advice.
Due to culture reason, make sure your son is sensitive to other kids. once i told my son one question was "easy". he told me it was not allowed to use "easy" in his class. his teacher said that it maybe easy for you, but may be hard to other kids, and they may feel hurt. since your son is smart and fast at his project, if he shows any disapproval of his parterner (even unintentional), others may want to stay away from him.