Genetics is the scientific discipline devoted to studying and manipulating heredity and variation in living organisms. When genetics took shape as a discipline at the beginning of the 20th century, eugenicists embraced the budding field because it was thought that the discipline offered a scientific foundation for eugenic beliefs and policies. Traits ranging from criminality to intelligence, eugenicists thought, could be linked to genes for criminality and intelligence. This meant that multiplying or eliminating the relevant gene(s) could achieve the challenge of decreasing criminality or increasing intelligence. As the science of genetics matured, however, it became clear that the relationship between genes and traits was much more complex than eugenicists imagined. Eugenic ideas, however, did not disappear. Some critics have identified a “newgenics” that persists into the present, which takes the increasing complexity of genetics serious while still trying to control human heredity.

Genetics: The Science of Heredity
Genetics took shape as a discipline at the turn of the 20th century. At that time, Gregor Mendel’s research on pea plants (e.g. round vs. wrinkled peas, purple vs. white flowers, long vs. short stems) was rediscovered after nearly forty years of neglect; Mendel’s principles of segregation, independent assortment, and dominance formed the empirical foundation for a new science tasked with discovering the physical unit of heredity. For geneticists, the physical unit was the “gene” (what Mendel referred to as “factor”). Geneticists sought to link traits in organisms with genes on the chromosomes of those organisms, tracing how traits were transmitted from generation to generation and how variation emerged in that process. Importantly, geneticists were not just interested in understanding this hereditary process; they wanted to use that knowledge to manipulate and control heredity by, for example, increasing crop yield or breeding hardier livestock. The success of agricultural genetics is a testament to the ability—in certain contexts—of being able to manipulate and control heredity.

Genetics: In Service of Eugenics?
Might human genetics, like agricultural genetics, also be susceptible to manipulation and control? Eugenicists hoped so. In the early decades of the 20th century, eugenicists were concerned that the unfit were out-breeding the fit—that individuals with traits like criminality, degeneracy, pauperism and feeblemindedness were having more and more children, while individuals with high intelligence, strong leadership abilities, and creativity were having fewer and fewer children. Overlaid with this attention to eugenic traits was a belief that the desirable traits were most common among the socioeconomic group occupied by the eugenicists (largely middle- to upper-class whites), while the undesirable traits were most common among socioeconomic groups deemed of less value by the eugenicists (largely lower classes, minority groups, and immigrants).

Before genetics came along, eugenicists shaped their concerns in terms of protecting the “human germ plasm” and the “national protoplasm”. When genetics arrived with its focus on genes as the physical unit of heredity, eugenicists largely adopted this scientific development and co-opted the new field as the scientific foundation for their social vision. Human genetics, as eugenicists saw it, simply was eugenics. So the eugenic fight to decrease traits like criminality and feeblemindedness became reframed as a fight to eliminate genes for criminality and feeblemindedness, and the eugenic effort to increase traits like intelligence and leadership became reframed as an effort to multiply genes for intelligence and leadership.

Eugenicists employed a variety of different forms of eugenics to proceed with their vision. To eliminate genes from the unfit, eugenicists employed negative eugenics: people with traits like feeblemindedness were exposed to involuntary sterilization so that they could not pass their genes on to another generation; anti-miscegenation (or anti “race-mixing”) laws were passed to prevent people with good genes from marrying people with bad genes; and immigration restriction acts were enacted to prevent people from regions of the world deemed to carry bad genes from entering the nations where eugenicists lived. To multiply genes from the fit, eugenicists employed positive eugenics; for example, fitter family contests were held, where families deemed especially fit were honoured for their eugenic contribution to society, and eugenic sermon contests were organized, where pastors could be awarded for taking the message of good breeding to their pulpits. The union of eugenics and the nascent field of genetics was a particularly forceful combination. Eugenics was most influential in the first three decades of the 20th century after it embraced genetics and as genetics was in the infancy period of its development.

Genetics: In Conflict with Eugenics
As genetics matured, however, it quickly became clear that the eugenicists’ simplistic understanding of heredity did not match the complex, biological reality. Traits as complex as criminality and intelligence, it became clear, were not transmitted from generation to generation in the same fashion as flower color or pea shape. Geneticists came to realize that the dichotomous notion of “nature versus nurture” was misleading, since complex human traits were the developmental products of many, many genes, along with many, many environmental factors.

By the 1930s/1940s, the science of genetics thus came to directly undercut the rationale for eugenic policies. Attempts to increase intelligence or decrease criminality could not simply be targeted at increasing or decreasing the breeding of individuals with those traits. If a life of poverty was largely the result of environmental exposure to poverty, then no amount of immigration restriction would eliminate pauperism if impoverished environments continued to persist in a nation. If criminality was in part the result of many, many genes, then no amount of sterilization would eliminate crime because even people who did not engage in criminal behavior could carry genes associated with the trait and pass them on to the next generation. And if there was no single gene for intelligence, then no amount of eugenic match making would ensure that each new generation would be more intelligent than the last.

This scientific development, however, did not mean that the eugenic interest in controlling human heredity disappeared. Medical genetics, which thrives today in hospitals and medical schools, continues to utilize information about human heredity in order to intervene in that process. Prenatal testing, for example, utilizes genetic information about parents and/or a fetus to provide information about the potential traits of that fetus, allowing parents, for example, to terminate a pregnancy if they deem the fetus’ life would not be worth living (or prepare themselves for living with a child that has some particular condition). Unlike involuntary sterilization or immigration restriction, prenatal testing puts the attempt to control human heredity into the hands of parents (rather than the state). And unlike involuntary sterilization or immigration restriction, prenatal testing typically focuses on genetic conditions that do follow patterns of Mendelian inheritance (unlike criminality and intelligence). Still, the utilization of genetic information to decide, for example, whether or not to terminate a pregnancy, harkens back to eugenic interests in controlling human heredity.

Conclusion
Eugenics became less and less popular as the 20th century advanced. Part of the decline in popularity was surely social. After World War II, the world learned more about the atrocities enacted by the Nazis, who employed eugenic arguments to justify their actions; couples sought to marry and have families based on love rather than based on some eugenic obligation to a fitter future generation; and minority groups fought to bring attention to the systematic environmental disadvantages they were exposed to as a result of the biases of more powerful groups. But the erosion of eugenics was also surely a scientific story: As genetics became a more mature science, it simply did not support the eugenic understanding of how heredity works. And when that happened, eugenicists no longer could claim to be supported by legitimate science. Still, eugenic ideas persisted. Some critics have argued, for example, that prentatal testing is a form of “newgenics” because it is a modern instantiation of individuals utilizing genetic information to control human heredity.

-James Tabery

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