These questions become even more subtle and interesting when they're addressed to a distinct and enduring traditional cultures coexisting within the boundaries of a large and complex society.  Certainly Americans visiting abroad have no trouble recognizing their fellow countrymen and women, be they black or white, descended from Mexican or Polish ancestors, rich or poor.  As a people, we have much in common, a great deal that we more or less share: a recent history, a language, a common denominator of popular music, entertainment, and politics. But, if we are fortunate, we also belong to a small, more particular community, defined by ethnicity or kinship, belief system or geography.  It is in this intimate circle that we are most "ourselves," where our jokes are best appreciated, our special dishes most enjoyed.  There are the people to whom we go first when we need comfort or empathy, for they speak our own brand of cultural shorthand, and always know the correct things to say, the proper things to do.