Ethnocentrism refers to the belief that one's own ethnic group is superior to others. It involves judging other groups from the perspective of one's own ethnicity. The term was coined in the 19th century by Polish sociologist Ludwig Gumplowicz to describe this view that one's own ethnic group is central to reality. In the early 20th century, American sociologist William Graham Sumner further defined ethnocentrism as the view that one's own group is the center of everything, and that all other groups are rated in comparison to it.