You can point out the stereotype and show how it can be limiting or hurtful of the person being stereotyped.

You should ask yourself if you have done anything to present yourself as a stereotype and then address it with others and try to keep it in mind for yourself also.

You can give them your personal view of their competence and then give examples of how they are underestimating themselves and their strengths.

Others are treating them according to perceptions rather than their actions. Indicators can be comments others are making.