“What is your ancestry?” Chances are, we’ve all heard this question from time to time. Often, we’ll respond to this line of inquiry with something similar to: “oh, I’m about three-quarters Scottish, one quarter Danish.” But have you ever stopped to consider just where the idea came from? At some point, someone came up with the idea that our parents’ lineage constitutes 50% of our genetic inheritance, our grandparents make up 25%, and so on. While reading “Eugenics as Indian Removal,” an article in The Public Historian 29, No. 3, it struck me that this very idea, which we often so easily dismiss as a simple conversation starter, became the basis for the eugenics movement, and numerous policies that persist even today.
The idea that one inherits racial and ethnic traits from one’s parents (the percentages for which decrease as you go higher up in the family tree), is called “fractional inheritance,” and it first appeared in the writings of Sir Francis Galton in the late nineteenth century. Fractional inheritance then led to the logic that a person’s racial identity could be assigned based on the race of his or her most socially subordinate parent. For example, Virginia’s 1866 declaration that “every person having one-fourth or more Negro blood shall be deemed a colored person, and every person not a colored person having one-fourth or more Indian blood shall be deemed an Indian,”  This practice was known as hypodescent, and together with the notion of fractional inheritance, they formed the basis for the “science” of eugenics.
After the Civil War, Progressives throughout the South latched onto the idea that science could contribute to real, quantifiable social reform. They came to believe that biological determinism, and the study of the role one’s genes play creating behavior, could be used to better society. With the scientific trifecta of fractional inheritance, hypodescent, and biological determinism, scientists had all the evidence they needed to link race to behavior. In the North, progressives were bolstered by scientific evidence collected by Henry Goddard, Charles Davenport, and others.
And here is where things get just a bit more complicated. It would be easy to say, simply, that these ideas led to negative eugenics, and to leave it at that. But then, somehow, they became policy at the federal and state levels. For instance, the federal government passed the Johnson-Reed Act in 1924, putting a stranglehold on immigration from the Mediterranean and Eastern Europe. In the South, anti-miscegenation laws attempted to limit the interaction and reproduction between whites and blacks. As these laws across the country were deemed inadequate to protect racial progress, many states began to implement forced sterilization programs. North Carolina, for example, passed laws in 1919, 1929, 1933, 1935; Virginia did in 1924. Then, in 1927, the United States Supreme Court upheld Virginia’s forced sterilization law in the case of Buck vs. Bell. While the case of Buck vs. Bell concerned a patient in a mental health facility, and did not focus on the lineage of the person in question, it essentially legitimized the practice of eugenic sterilization in general. For several decades following the ruling, sterilization efforts focused on the “feebleminded” or the “degenerate.” However, as federal policies shifted and public health facilities began to desegregate, sterilization of Native Americans and other groups skyrocketed due in large part to coercion and other practices at state-run healthcare providers. 
Hypodescent, and thus the ability to negatively categorize human beings by their parental heritage, were obviously at the core of each and every one of these policies. Even though eugenics has been discredited from an ethical standpoint, we continue to use the ideas at its heart to influence and create policy. Native American tribes, for example, still determine lineage and tribal ancestry through the use of the “blood quantum.” Society also identifies a person as “mixed-race” based on the skin color of their parents. We still consider the notion of fractional inheritance to be a determining factor in a person’s identity, and we still develop policies operating under that assumption. Is this right or wrong? I will let you decide.
 “Eugenics as Indian Removal: Sociohistorical Processes and the De(con)struction of American Indians in the Southeast,” The Public Historian, Vol. 29, No. 3 (2007): 56.
 Ibid, 57-60.