Define Your Looks

Today in class, Sal was talking about how different cultures define people on the way they look. For example in the United States you are either caucasian, african american, asian, pasific islander, or indian. In African there are 8 different categories of race. You can change your race as long as you can prove your ancestry unlike in America you are what you look like. Other countries have different categories for different races. My freshman year of high school during world history my teacher had on the board "What is your nationality?" and you discussed it with the people around you. Everyone was saying my mom is from this country or my grandparents are from this country. I consider myself to be 50% German, 25% polish and 25% Russian because that is all were my grandparents are from, but how can you be only part Russian or Polish? At the end of the activity we discussed with the class and everyone walked out trying to figure out why we wasted the whole class time on this. It took me until my junior year to understand that fact. In American we consider our self to be from different countries that our nationality isn't American. Why is this? Just like in Africa you can change your race category, Americans don't view themselves in one way but in many ways. Why do we want to change who we are?