This is especially true in how we see ourselves and how others see us. This is, in Jungian terms, called Persona and Shadow. Persona is how we want others to see us, the ideal image of ourselves (like), while Shadow is a collection of negative images we hide in our subconscious mind (dislike). The big problem is that we then project the Shadow onto others to dehumanize and demonize, the classic example being the foisting of the German national Shadow of untermenschen (ie sub-human), onto the Jews, rendering them expendable, rationalizing their extermination as 'defective'. But on a daily basis all around the world, Shadow is being foisted on one another all the time in all spheres of existence, having especially taken root in the young with our current problem of bullying. It's an epidemic.