If you refused to bow when greeting a Japanese friend, insisting on shaking hands instead, you'd be displaying your ethnocentrism, or your belief that your own culture is superior to others.

Anyone who judges people or traditions based on his own cultural standards is guilty of ethnocentrism. It means believing that the way you're used to doing things is the only right way to do them, and that people or cultures that do things differently are wrong. Ethnocentrism comes from the Greek ethno, or "people" and centric, "center;" so when you put your own people, or culture, at the center of the world, you're letting your ethnocentrism show.

Definitions of ethnocentrism

n belief in the superiority of one's own ethnic group

Type of:
partiality, partisanship
an inclination to favor one group or view or opinion over alternatives