Relationship of Self-Identity and Genetic Ancestry
Contrary to expectations under a social one-drop rule, or “Rule of Hypodescent,” which would mandate that individuals who knowingly carry African ancestry identify as African American, the probability of self-reporting as African American given a proportion of African ancestry follows a logistic probability curve (Figure S9A, Table S6), suggesting that individuals identify roughly with the majority of their genetic ancestry (Figures 4 and 5A). Individuals with more than 5% Native American ancestry are most likely to self-identify as Latino (Figures S9C and 5B), suggesting differences in sociological or historical factors associated with identifying with these groups. The transitions between Latino, African American, and European American self-reported identity by proportions of African and Native American ancestry illustrate both the complexity of how one self identifies as well as the overlapping ancestry profiles among groups (Figure 5B).