Evidence for this theory often includes the kind of language or rhetoric that is used in the buildup to (or in the subsequent justification for) extreme violence against groups of people, such as the Rwandan genocide, or the Holocaust. In both of these cases, the victims were characterized as “cockroaches” or “vermin” that needed to be exterminated by the perpetrators of the violence. They were dehumanized, thus making acts of extreme cruelty possible.