On the Boundaries of Race: Identification of Mixed-heritage Children in the United States, 1960 to 2010

Socially constructed race groups have boundaries that define their membership. I study temporal trends and group-specific patterns in race and ancestry responses provided for children of interracial marriages. Common responses indicate contemporary definitions of race groups (and perhaps emerging groups); uncommon responses reveal socially defined limits of race group membership. I leverage dense, nonpublic, Census Bureau data from 1960 to 2010 to do this and include a more diverse set of families, a longer time span, and more accurate estimates than prior research. I find that the location of race group boundaries varies over time and across 11 distinct family types. Since mixed-heritage responses became possible in 1980, they have been common in most groups. Part Asians have almost always been reported as multiracial or mixed ancestry. A number of (non-Asian) mixed-heritage children are described as monoracial on the census form, particularly children with American Indian heritage. Over time, part whites are decreasingly reported as monoracially white (white race with no nonwhite ancestry). Black heritage is reported for part blacks, but monoracial black responses became nonmodal by 1980. Part Pacific Islanders show similarities to part Asians and part American Indians. Given the predominance of multiracial and mixed-ancestry Asian responses since 1980, Asian multiracial may be an emerging socially recognized race category. Black multiracial shows a similar pattern. Monoracial responses (especially common among white-American Indians and black-American Indians) create important but hard-to-measure complexity in groups' compositions.