Please think of examples of both subcultures and countercultures in the United States. Ethnocentrism is a cultural judgement. It is a universally encountered pattern of viewing one's own culture and experience as superior. We may use our own cultural experience as the yardstick for comparing other cultures. Usually, when this is the measure, the other culture will be found lacking in some way.
Ethnocentrism is a by-product of the socialization process.
Often, we suggest that cultural relativism is the opposite of ethnocentrism. Cultural relativity defers judgement in favor of objectivity and understanding of someone else's way of life. It is a suspension of judgement in favor of understanding. Both of these concepts are very important for us in the United States. We need to employ cultural relativity whether we are looking at another culture or at a subculture within our own society.