Somewhere For Me
All Star
Because it's a social construct by definition, stemming from the human desire to label or categorize. Want some somewhat entertaining examples? Take a look at any thread about a mixed *Black* individual and see people struggle to decide whether the individual is mostly, Black, White, etc. The subject of genetics is a very complicated one. Religion though? One can't even fathom all of the flagrant things that have occurred as a result of religion.
A lot of people still seem to follow the archaic three races (Caucasoid, Negroid, and Mongoloid) ideology. What a lot of people don't know is that ideology is a deeply flawed one based on racism and pseudoscience.
It's particularly hard on Americans to understand because we never had a culture based on diverse tribal ethnicity like other places. Over here, whatever you "look" like, is what you get labeled with regardless of what your ethnicity or nationality is. We are more obsessed with phenotype and parentage than ethnic, national, or tribal identities/connections.