The kid I mentioned in an earlier post won some sort of district or state math competition in second grade. The school does not promote these competitions, the parents signed her up independently. The kid wanted to bring in her trophy for show-and-tell and the teacher refused to allow her to do that or talk about it. She said that would be bragging. This teacher also told the parents "There's nothing I can do for your DD" when they asked about getting her higher level math.
If the kid had won a swim competition would there have been the same response? No sports trophies brought in for show-and-tell? Somehow I don't think so.