Demographic Data : Race, Ethnicity, and Gender

What are commonly known as "demographic characteristics" include a person's sex, ethnic or hacial heritage, family ties, and so on. Some of these, like martial status, can reglect a person's choices or efforts; others, like age and sex cannot. Ethnic background, or classification by race, might seem totally exogenous to the individual : how can one change the color of one's parent's skin or the culture of one's grandparents' origin? But in fact some individuals can freely choose to define themselves as white, black, Hispanic, Asian, and so forth while other individuals can downplay or emphasize these characteristics of their birth and upbringing.