Guest post by Amanda N. Weiss
People have long used selective breeding of crops and livestock to produce food and work animals with traits suited for our purposes. But ideas about good breeding stock have also seeped into the conversation about human traits throughout history, crossing the boundaries of morality and science.
The eugenics movement through the 1900s
In 1883, Sir Francis Galton first used the term “eugenics” to describe the idea of cultivating desirable traits within the human population by “improving stock”. There are two arms of eugenics: positive eugenics, which seeks to promote reproduction of the “right” people, and negative eugenics, which seeks to prevent “wrong” or “defective” people from reproducing. In the minds of eugenicists, people of color were among those cast as undesirable due to fears about race-mixing and “race suicide”. Another major target of the eugenics movement was mentally disabled people, referred to as “feeble-minded”, who were portrayed as diseased, animalistic, and destructive.
Some eugenicists appealed to the theories and work of scientists to support their claims. Gregor Mendel’s work cross breeding pea plants in the 1800s had demonstrated laws of genetic inheritance for certain traits, and some eugenicists incorrectly applied these laws to complex traits such as intelligence or criminality, which we now know result from a combination of many factors. Additionally, some eugenicists, including Caleb William Saleeby, focused on protecting in utero fetuses of the “right” kind of parents from exposure to toxins such as alcohol.
Many disciplines were part of the eugenics movement, and the medical field helped to legitimize eugenics as a science in the public eye by subsuming it under the banner of its expertise. Researchers in the United States also played a major role in the eugenics movement. In the early 1900s, at the request of zoologist Charles B. Davenport, the Carnegie Institution started a research station to study evolution, including “race change”, at Cold Spring Harbor Laboratory in New York. Less than a decade later, the Eugenics Record Office was established there. This office collected information about physical and mental traits, traced through family lines. Some leaders of this office, such as educator Harry Laughlin, advocated for eugenic government policies, including restricting immigration of “antisocial, and otherwise undesirable, persons” and sterilizing “unfit” people to prevent them from reproducing. Another entity associated with the Eugenics Record Office was the Eugenic Section of the American Breeders Association, which had research committees dedicated to areas including “Heredity of Feeble-mindedness”, “Heredity of Criminality”, immigration, and sterilization.
However, not all scientists were on board. From early on in the eugenics movement, some scientists rejected the oversimplification of gene-trait relationships and the flawed methodologies of many eugenics research studies; even some eugenicists were critical of the quality of eugenics research. One prominent opponent of eugenics was Lionel Penrose, an English scientist whose research focused on understanding mental disorders. He helped discover that environmental factors and genetics both contribute to mental disabilities. Penrose also changed the title of the journal Annals of Eugenics to Annals of Human Genetics in 1954. Likewise, in the 1960s, following Penrose’s suggestion, University College London changed the name of its Department of Eugenics, Biometry, and Genetics to the Department of Human Genetics and Biometry.
Despite the opposition, eugenic ideals found their way into public practice, including public health. While some eugenicists believed that stopping the spread of germ-based diseases was interfering with natural elimination of the “unfit”, others believed that public health measures helped to preserve the “fit” along with the “unfit”. Both public health and eugenics sought to rid society of what they considered to be illnesses that threatened the well-being of the population.
Options mentioned for eliminating unwanted traits included euthanasia, as mentioned in a report by the Eugenic Section of the American Breeders’ Association, and execution, as discussed in the 1918 textbook Applied Eugenics. However, both documents focus more on sterilization of the “unfit”, and Applied Eugenics states that execution has “value in keeping up the standard of the race”, but “is wholly out of accord with the spirit of the times, and is not seriously considered by the eugenics movement”.
Indeed, sterilization became a major fixture in the United States’ eugenics policy. Over 30 states in the U.S. ended up with sterilization laws on the books, and the 1927 Supreme Court case Buck v. Bell upheld a state’s right to forcibly sterilize people. Notably, Carrie Buck, the young woman whose sterilization was the subject of this case, had been committed to a mental institution after giving birth from a pregnancy from rape by her foster mother’s nephew at age 17. Altogether, these laws and practices resulted in at least 60,000 sterilizations of people in institutions before World War II. Later, in the 1970s, there was also a huge wave of sterilizations of Native American women, including many procedures performed without consent.
The eugenics programs in the United States were also influential beyond the country’s own borders. Nazi Germany took inspiration from U.S. immigration policy and sterilization laws for its own “racial hygiene” program, and U.S. eugenicists likewise supported Nazi eugenic policies.
After WWII, in 1953, the double helical structure of DNA was discovered by James Watson, Francis Crick, and Rosalind Franklin (though Franklin was not appropriately credited at the time). Despite being involved in a critical step forward for genetics, Watson later came to be known for his racist and sexist remarks that echoed eugenic thought. Watson believed intelligence was based on genetics, such that African American people were inherently less intelligent, and that the gender disparity in science may be due to women being inferior by nature. In his later years, Watson was largely shunned by the scientific community, and several articles have been written about his controversial legacy in the wake of his recent death.
Modern-day influences of eugenics
These days, it’s generally accepted that this traditional form of eugenics reflects prejudice rather than actual science. So, why is it so important for us to keep eugenics in discussion, especially within the scientific community? Ultimately, eugenics underlies the origins of some current practices and continues to haunt legal policy.
Several pieces of healthcare that we benefit from today grew from eugenic roots. For instance, Margaret Sanger, the nurse who drove forward the push for birth control education and access in the United States, allied herself with eugenicists and wrote about birth control as a tool for preventing the breeding of people considered “unfit”. Additionally, the profession of Marriage and Family Therapy was originally closely associated with eugenic ideas about promoting the “right” kind of marriages to improve future generations.
Eugenic lines of thought have also persisted in some modern genetics research, even though most contemporary scientists would reject the idea of eugenics overall. In the first decade of the 2000s, a small sample genomic study found that a specific version of the “warrior gene” occurs frequently in the Mãori people of New Zealand, and one of the researchers made a controversial claim about the gene and predisposition for criminal behavior. The Mãori population is stereotyped as aggressive and discussion around the “warrior gene” does not always emphasize the importance of environmental effects on traits associated with this gene. Additionally, this version of the gene also appears with high frequency in several other populations. In the present day, as gene editing technologies improve, we are also faced with questions about the morality of editing genes to enhance certain traits. Some are in favor of “liberal eugenics”, wherein parents can use reproductive technology to select for desired traits in their own children. However, the line defining traits that are pathological, or reasonable to select for or against, is not always clear.
Furthermore, eugenic threats continue to loom over people with disabilities. A study published in 2022 found that 31 U.S. states and Washington, D.C. still had laws on the books that allowed for disabled people to be forcibly sterilized. Less directly, policies regulating disability benefits may affect a disabled person’s ability to have enough financial security to have and raise children. For instance, in order for a non-blind disabled person to receive Social Security disability benefits in 2025, they must not earn more than $1,620 per month. Additionally, Supplemental Security Income, which some people qualify for based on a disability, may be affected if the recipient gets married. Likewise, if a “disabled adult child” (an adult whose disability started before they turned 22 and whose parent(s) receive or were insured for Social Security benefits) gets married to someone who is not a “disabled adult child”, they will lose their Social Security Disability Insurance. If a disabled person relies on their benefits to stay alive and well, marriage may not be an option; through financial requirements, laws indirectly restrict the choice of people with disabilities to have children.
Notably, disability rights advocates and civil rights organizations expressed concern when the National Institutes of Health Director Jay Bhattacharya proposed a plan for an autism registry earlier this year. Though the Department of Health and Human Services stated soon after that the data platform would not be a registry, concerns remained about lack of communication with advocates and data privacy. There was also no guarantee that the data would be used to help people with autism rather than hurt them.
In addition to disability-related concerns, some of the anti-immigration rhetoric prevalent in more recent times echoes the sentiment of early 1900s eugenics. According to NPR/Ipsos polling, the percentage of respondents who falsely believed that immigrants are more likely than U.S.-born people to be criminals or be in prison increased between 2018 and 2022. During President Trump’s campaigning in 2020 and 2023, he described his supporters in Minnesota as having “good genes” and undocumented immigrants as “poisoning the blood”. However, Gallup polling shows that in 2025, compared to last year, fewer Americans want lower immigration rates, and most Americans think positively of immigration, suggesting that anti-immigration sentiment may be falling out of favor.
Nevertheless, extremist views about racial inferiority of non-white people have inspired violence in recent years. Several mass shootings within the past decade have been associated with “Great Replacement” theory, which posits that the white populations in the U.S. and Europe are being replaced by immigrant people of color. This conspiracy theory originally gained prominence in the United States after eugenicist and environmental conservationist Madison Grant published his book, The Passing of the Great Race, in 1916.
Likewise, recent years have seen the rise of pronatalism, the promotion of reproduction, in the United States. Pronatalism arises from a fear about a decline in the population, and some pronatalists believe that some specific populations should reproduce more. At the first Natal Conference in 2023, speakers alluded to the need for “better” people to proliferate.
Conflict about “good genes” and white supremacy has also found its way into more mundane parts of the public sphere. A few months ago, American Eagle released an advertisement campaign with the tagline “Sydney Sweeney Has Great Jeans”, in which one of the ads features Sweeney saying that inherited genes determine traits, including the complex trait of personality. The campaign elicited backlash online from critics who felt that this ad coming from the mouth of a white, blue-eyed woman had eugenic undertones, but others felt that the backlash was “woke” and an overreaction. When asked in an interview about it, Sweeney replied that “[…] when I have an issue that I want to speak about, people will hear”, which sparked further backlash. Sweeney later said “I don’t support the views some people chose to connect to the campaign” and “I have come to realize that my silence regarding this issue has only widened the divide, not closed it.”
Mitigating eugenic thought through education
Given the persistence of eugenic influence in society, researchers have begun exploring genetics education strategies to minimize false beliefs about biology that align with eugenics. Namely, “humane genomics” education appears to reduce belief in genetic essentialism, which is the incorrect idea that genes determine traits in a fixed way and that race is a genetic categorization. Additionally, the Next Generation Science Standards include, at multiple grade levels, the concept that the environment affects traits.
Critical evaluation of genetics education and the history of eugenics also arose in a 2024-2025 exchange between prominent U.K. geneticists in the pages of the American Journal of Human Genetics. Adam Rutherford, a lecturer, former editor at Nature, and science communicator, argued that genetics education focuses too much on a simple gene-determines-trait model, and that teaching single-gene inheritance as introductory genetics leads students to develop incorrect understandings of the relationship between genes and traits. Meanwhile, Walter F. Bodmer, Head of the Cancer and Immunogenetics Laboratory at the Weatherall Institute of Molecular Medicine, and Brian Charlesworth, Professor in the Institute of Ecology and Evolution at the University of Edinburgh, argued that even during the height of the eugenics movement, some scientists criticized eugenics, and that single gene major inheritance does occur for many traits and thus serves as a reasonable introductory model. This discourse highlights the importance of considering how teaching methods for basic scientific concepts have implications beyond the classroom.
So, where does that leave us now, and what can we take away from the history of eugenics and its lingering impacts on society? We can’t look at the eugenic atrocities of the past that were rationalized with pseudoscience or misapplication of scientific ideas and think that they can’t happen here and now. Active work is needed to reduce the prevalence of genetic misconceptions associated with eugenic beliefs. Developments in teaching strategies hold promise for addressing this problem in upcoming generations, but scrutinizing broader aspects of society is necessary to understand and undermine the deeply entrenched eugenic roots that remain.
