One's sense of who one is as a person is produced out of a matrix of categories and labels that serve to identify one's place in society and, indeed, oneself: Catholic, democrat, college student, child of divorced parents, American, musician, etc. Sometimes specific identity categories or labels (the terms we use to identify who we are) feel completely determining, as for instance in the cases of someone who is gay or African-American. Postmodernism has attempted to destabilize identities while multiculturalism has attempted to celebrate and consolidate them.
An excerpt about identity by Paula Moya:
[Socially determined identities] can be enabling, enlightening, and joyful structures of attachment and feeling, [constituting] modes [of understanding, of thinking] by which people experience, understand, and know the world. The significance of identity depends partly upon the fact that goods and resources are still distributed according to identity categories. Who we are -- that is, who we perceive ourselves or are perceived by others to be -- will significantly affect our life chances: where we can live, whom we will marry (or whether we can marry), and what kinds of educational and employment opportunities will be available to us. . . . [P]ast and present structures of inequality . . . are often highly correlated with categories of identity.
. . . . Who we understand ourselves to be will have consequences for how we experience and understand the world. Our conceptions of who we are as social beings (our identities) influcence -- and in turn are influenced by -- our understandings of how our society is sturctured and what our particular experiences within that society are likely to be. . . . However, our different views about how our society is structured and where we and others fit into it are not all equally accurate. So, for example, a white man who identifies as a white supremacist might experience his job lay-off as a direct consequence of federal government or Jewish conspiracy rather than as a result of corporate consolidation or economic restructuring. In this case, his understanding about the way society is structured is more erroneous than accurate -- as are his ideas about his putative racial superiority. Identities are . . . often assumed or chosen for complex subjective reasons that can be objectively evaluated. (Paula Moya, ed., Introduction, Reclaiming Identity <http://www.eserver.org.clogic/3-12/moya.html> 5 Dec. 2003, pars.10-11.)