There is a large gap between the “self-reported” racial ancestry of Americans and what their DNA reveals, a new study has shown—confirming long-held warnings from those familiar with racial ancestry studies.
According to the paper “Subcontinental genetic variation in the All of Us Research Program: Implications for biomedical research” (published in The American Journal of Human Genetics), large numbers of “Blacks” and “Hispanics” who categorize, or “self-report” themselves as such (in U.S. Census returns, for example), are in fact highly racially mixed and do not fit into any single racial category.
The study was conducted by analyzing approximately 2 million genetic variants in more than 230,000 participants, a subset of the more than 400,000 people whose whole genomes are in the “All of Us” database.
The paper concluded that rather than fitting into clear-cut genetic clusters based on self-reported racial or ethnic labels, many participants’ genomes revealed “different gradients of ancestry spanning continents.”
“Notably, All of Us Hispanic or Latino participants spanned nearly the entire spectrum of genetic variation . . . Most Hispanic or Latino (92%) people did not self-identify within any specific race category, and those (8%) who did were represented across all possible predefined racial categories,” the paper reported.
In addition, those who identified as Black or African American had varying proportions of African and European genetic variation.
Among “Blacks,” Body Mass Index (BMI) measurements—a trait, which like all human traits, is genetically determined—were decided by regional African ancestry. West-Central African ancestry was associated with a higher BMI, whereas East African ancestry was associated with a lower BMI.
Significantly, the paper added that “race and ethnicity may serve as proxies for capturing socio-cultural or environmental factors that are not typically accounted for by standard covariates in association models”—in other words, that race and racial origin do indeed provide a model to study human populations.
