The human mind has adapted the capacity to deaden its own ability to percieve and look for stimuli if those stimuli are always negative. Some people have developed practices to avoid sucumbing to this process, but few people learn them these days.
Many cultures have a group of sayings and stories to help people who do these practices but they have largely been forgotten the world over.
When one group of people dehumanizes another through their behavior the other group gradually begins to be come dehuman. They stop being able to hear the other group, they stop being honest with them and they begin to view them as capable of nothing but inflicting harm. They stop believing in the ability to communicate with them using words.
There is little that can be done for any society who has discovered this phenominon and is using it to cause the poor or immigrant or minority populations within their societies to act up to the point where they can legally be killed or perminantly incarcerated. Once social policy reaches the point that a person can go years without any genuine communicative interaction with the dominant group perminant mental calcifications form. If this process goes on for too long people cant notice if you have changed.
Under normal circumstances in multi cultural and multi class societies people acknowlege a degree of humanity and a degree of variability in all groups. When this stops, people start killing eachother as if they are clearing a non human mass that is blocking them from obtaining the basics of life.
