Prejudice is a negative attitude towards a group based solely on membership in that group. There are three main types of prejudice: racial, automatic, and gender prejudice. Prejudice arises from desires to justify social status differences and childhood exposure, though it is not necessarily maintained into adulthood. Prejudice has motivational sources like frustration-aggression theory and social identity theory, and cognitive sources like categorization of people into groups and perception of differences between in-groups and out-groups. Ways to reduce prejudice include empathy training, anti-discrimination laws and regulations, changing social norms, increasing awareness of inconsistent beliefs, and more contact between groups.