Answer:
Prejudice or stereotype
Explanation:
If you think someone is good/bad of something due to their ethnicity or any underlying non related factors.
Prejudice definition.
1 : a liking or dislike for one rather than another especially without good reason She has a prejudice against department stores. 2 : a feeling of unfair dislike directed against an individual or a group because of some characteristic (as race or religion) 3 : injury or damage to a person's rights.
Stereotype definition.
noun
1.
a widely held but fixed and oversimplified image or idea of a particular type of person or thing.
"the stereotype of the woman as the carer"
Similar:
standard/conventional image
received idea
cliché
hackneyed idea
formula
2.
a relief printing plate cast in a mold made from composed type or an original plate.
verb
view or represent as a stereotype.
"the city is too easily stereotyped as an industrial wasteland"
Hope this helps!