The major case of extreme ethnocentrism that comes to my mind in the United States is during the second civil war. Racism was deep-seated, very powerful, and degrading. African Americans did not have the opportunities to go to school and become educated. When they did get the chance, they usually had to quit and take care of an ailing family member or because of work requiring them to do so. Segregation kept whites and blacks from associating with one another to understand more about each other from a personal level. This left white people feeling very superior and better than blacks; it left black people feeling alienated and unimportant in society. The effects of that time period are still felt today. The past is carried with us throughout future generations.
Another instance, outside of the United States of America, is that many Muslims may find the practices of European women that adhere to the adopted practice of polygamy there to be highly immodest and completely immoral. These attitudes of superiority or hostility can lead to discrimination and violence.
We need to look at ethnic backgrounds and belief systems from a more objective prospective if we ever want to put an end to all the hatred it ensues. We need to