All cultures have categories to distinguish people into “us and them” by ethnicity, race, religion, or nationality
organization
We give names or other symbols to the classifications. We name people “Jews” or “Gypsies”, or distinguish them by colors or dress; and apply the symbols to members of groups
polarization
One group denies the humanity of the other group. Members of it are equated with animales, vermin, insects or diseases. Dehumanization overcomes the normal human revulsion against murder
preparation
Genocide is always organized, usually by the state, often using militias to provide deniability of state responsibility. Special army units or militias are often trained and armed.
Extremists drive the groups apart. Hate groups broadcast polarizing propaganda.
Victims are identified and separated out because of their ethnic or religious identity. Death lists are drawn up. Members of victim groups are forced to wear identifying symbols