5 causes:
1) Dissimilarity & Social Distance: Appearance, race, religion, economic, food preferences, skin color (in-group)
2) Economic Competition: Threatens economic benefits or jobs at other group's expenses
3) Scapegoating: Receives blame when others feel threatened; skin color, distinctive physical features
4) Conformity to social norms
5) Media stereotypes
6) Dehumanization: Psychological process of thinking abt certain other people/ groups as less than human