Ethnocentrism, coined by William Graham Sumner, is the viewpoint that one's ethnic group is the center of everything, against which all other groups are judged. Within culture, language, behaviour, customs, and religion can be a basis for ethnic distinctions, and sub-divisions.
In the modern world, however, the crossing of the lines between cultures, that at one time happened only occasionally, has become an everyday occurrence. Technological advances in communication have progressively overcome previous obstacles to communication - physical obstacles that once helped to keep ethnic distinctions distinct. Ethnic lines still exist, and co-exist, and cultures of the world often find that their central concern, that of maintaining an identity despite rapid transculturation, is still possible.
The reasons for maintaining an ethnicity are often personal, and relate to the cohesion of familiar personal and social elements - in other words, attachment or accustoment. We all are born into a human culture, and it is the culture that shapes our self-awareness and understanding of other individuals. It also reflects, depending on the cultural teaching, customs or patterns of behaviour in relating to other cultures. This behaviour can range from universal acceptance or feelings of inferiority compared with other cultures, to racism, which many consider an aspect of xenophobia.