There is not a kid alive who hasn't been teased about their appearance at one time or another or who has not teased another kid about some aspect of their clothing, accessories, or non-race based physical attributes. As for "boosting self-esteem" I hope that my kids have a strong enough sense of self to work out how to handle unkind comments without an adult rushing in to help them. I would think if parents rushed in, it would only make the teasing worse. I'm talking teasing, transient unkind comments, not bullying or racist remarks. I'm sick of all these overprotective parents who don't want their children exposed to any kind of criticism or comments that might damage their fragile little egos. I think the real question you should be exploring is how parents can tell teasing from bullying and recognize when their kids need genuine help.