Allport's Scale

The scale

1. Antilocution: Antilocution occurs when an in-group freely purports negative images of an out-group. Hate speech is included in this stage. Although antilocution itself may not be harmful, it could set the stage for more severe outlets for prejudice.
2. Avoidance: Members of the in-group actively avoid people in the out-group. No direct harm may be intended, but psychological harm often results through isolation.
3. Discrimination: The out-group is discriminated against by denying them opportunities and services, putting prejudice into action. Behaviors have the intention of disadvantaging the out-group by preventing them from achieving goals, getting education or jobs, etc. Examples include Jim Crow laws in the US, the Statute of Kilkenny in British Ireland, Apartheid in South Africa, the Nuremberg Laws in 1930's Germany and antisemitic laws in the Middle East.
4. Physical Attack: The in-group vandalizes, burns, or otherwise destroys out-group property and carries out violent attacks on individuals or groups. Physical harm is done to members of the out-group. Examples include pogroms against Jews in Europe, the lynchings of blacks and Italians in the US, ongoing violence against Hindus in Pakistan and Muslims in India.
5. Extermination: The in-group seeks extermination or removal of the out-group. They attempt to eliminate either the entirety or a large fraction of the undesired group of people. Examples include the Cambodian genocide, the Final Solution in Nazi Germany, the Rwandan genocide, the Armenian Genocide, the Genocide of the Hellenes and ethnic cleansing in the Bosnian War.