DNA, Self-Reported Ancestry, and Social Scientific Inquiry

• In Event: Advances in Social Science Genomics (Co-sponsored by Sociology of Population Section)

Abstract

Today, one in five Americans has taken a genetic ancestry test (GAT), which estimates the proportion of a person’s DNA that falls into various geographic categories. While much research has focused on [i] conceptually distinguishing race from ancestry and [ii] exploring how people interpret GAT information, few social scientific studies have constructed and utilized these quantities – which we call genetic similarity proportions (GSPs). Consequently, the empirical distributions and measurement properties of GSPs remain underexplored. After conceptually distinguishing between genealogical and genetic ancestry, we leverage computational genomic methods to estimate GSPs of genotyped respondents from the nationally representative Add Health study. Utilizing a unique survey question on respondents’ self-reported ancestral countries, we observe that – although a person’s self-reported ancestry is associated with their GSPs – there exists considerable variation in GSPs among individuals with the same self-reported ancestry. In addition, among respondents who self-report ancestry from the Americas and/or from Sub-Saharan Africa, GSPs are robustly associated with skin tone and racial classification; this suggests that such measures index individual characteristics that are racialized in contemporary American society. We close by discussing how GSPs could inform demographic research on the evolving racial, ethnic, and ancestral diversity of the United States.

Authors

• Luyin Zhang, Princeton University

• Sam Trejo, Princeton University