People shouldn’t be treated differently just because they look different.
Sadly, both children and adults frequently engage in this inappropriate behavior. Ask Ilka Brühl, who was born with the rare genetic condition ectodermal dysplasia, which caused her face to change shape.
A German student who received verbal abuse at school ended up wishing she could disappear in some way. She also did well in school and came to the realization that sharing her experience could also help other people.