Outgroup Homogeneity Effect: The perception that individuals in the outgroup are more similar (homogeneous) than they really are, as well as more similar than the members of the ingroup.
Prejudice:A preconceived opinion about someone based on their membership in a particular group, which isn't based on reason or actual experience.
Discrimination:Unjust treatment of different categories of people or things, especially on grounds such as race, age, or sex.