When Donald Trump talks about undocumented immigrants, he often brings up genetics.
Immigrants are “poisoning the blood of our country,” he said at a rally last year.
“Many of them murdered far more than one person, and they’re now happily living in the United States,” he said earlier this month. “You know, now a murderer, I believe this, it’s in their genes. And we got a lot of bad genes in our country right now.”
The former president’s language underscores a larger trend, experts tell STAT. The eugenics movement is once again taking center stage in the U.S. — both in the immigration policies and rhetoric promoted by Trump, and through a rise in race science in academic literature.
Eugenics — the pseudoscientific idea of fixing social problems through genetics and heredity via policies ranging from selective breeding to forced sterilization and genocide — was popular at the turn of the 20th century, before the devastation of the Holocaust quelled public support for it. The reasons for its resurgence include an increase in funding of race science from private donors, as well as proponents of scientific racism and white nationalists manipulating the push to make science more public.
Even well-intentioned scientists have fed into this shift by promoting genetic determinism — the idea that genes are the primary driver of traits and behaviors — and by platforming problematic work in the name of academic freedom.
“I wasn’t surprised that people are being demagogic about this stuff, but I am a little surprised that they’re so clearly not even hiding [it],” said Paul Lombardo, a professor of law at Georgia State University who has done extensive work on the legacy of eugenics. “This is not just saying the quiet part out loud. This is coming up with quotations in which, instead of using quotation marks, you’ve got swastikas at each end of the sentence.”
‘Bad genes’ and the birth of eugenics
Trump is frequently accused of racism, but the fact that he is embracing eugenic thinking has not drawn sufficient attention, according to Shannon O’Brien, a political scientist at the University of Texas, Austin, who has written a book on eugenics in American politics.
While racists harbor hatred for others because of their ethnicity or the color of their skin, eugenicists take it a step further and “like to legislate people out of existence,” O’Brien said. “They are OK with sterilization. They’re okay with extermination, and they believe that certain groups are superior and it’s OK to enact things that make it difficult for other ones to exist. I find that far scarier than racism.”
Asked about Trump’s rhetoric and the eugenics movement and his remarks about “bad genes,” Karoline Leavitt, the campaign’s press secretary, told STAT, “President Trump was clearly referring to murderers, not migrants.’’
The former president also has a history of statements suggesting that certain people are genetically superior. A 2016 documentary pointed out Trump’s father, Fred, introduced him to “racehorse theory” as a child — the idea that “that if you put together the genes of a superior woman and a superior man, you get superior offspring.” He’s used this idea to promote his own intelligence as well. “I had an uncle who went to MIT who is a top professor, Dr. John Trump. A genius. It’s in my blood. I’m smart,” he told CNN in 2020.
This way of talking about genetics is rooted in a long history that begins with the English anthropologist Francis Galton, who took his cousin Charles Darwin’s theory of evolution and applied it to humans, first using the term eugenics in 1883. The nascent field of eugenics matured into a full-fledged field of study in the United States. Much later, in the 1990s, the sequencing of the human genome inadvertently created a new surge in eugenics — emboldened by the idea that scientists could isolate genes responsible for complex behaviors, like poverty, crime and intelligence.
How companies like 23andMe bolstered genetic determinism
Those affiliated with the Human Genome Project hoped sequencing the genome would end notions that genetics created significant differences in different groups — “that it would lead us to this post-racial world,” said Aaron Panofsky, the director of the Institute for Society and Genetics at the University of California, Los Angeles.
“But it turns out that both scientists and the public spend all their interest in the 0.1% of genetic variation that makes us different, not the 99.9% that makes us the same.”
In promoting their research to the public and getting research funding from the government, geneticists often hyped up the role genes play in people’s lives. The Human Genome Project “was a huge public undertaking,” said Emily Merchant, a historian of science at the University of California, Davis. “It was almost $3 billion and took more than a decade to complete. So it needed a lot of popular support. The scientists who were trying to generate that popular support did it by promoting genetic determinism.”
This sentiment persisted in ensuing years because of popular genetic testing companies like 23andMe and Ancestry.com, which marketed its products with the premise that an understanding of genetics held the secret to good health and could quantify people’s sense of belonging to racial or ethnic groups.
In the early 2010s, there was another shift in how mainstream academic circles discussed ideas that intelligence was genetic or that race had a biological basis. Richard Lynn, a psychologist who claimed that people from certain countries had lower IQs, promoted a biased dataset on IQ differences between countries that became increasingly widespread in academia. Another theory, called “differential K theory,” began to circulate around this time, stating that Black people have lower IQs and are more aggressive.
“The national IQ database, differential K theory, they should have died the death bad science deserves to die. They have no scientific merit,” said Rebecca Sear, an evolutionary behavioral scientist at Brunel University who has documented the resurgence in eugenics in demography. “They’ve both been extensively critiqued. They are both currently thriving in the academic literature.”
While controversial among the scientific community, ideas like Lynn’s continued to spread in academia, in part because of the ethos of academic freedom — the idea that scholars should be able to research and debate any issues in their field, and that rejecting a paper based on problematic findings is tantamount to censorship.
“That’s a very, very problematic argument, but I think it is quite widespread,” Sear said. “Academic freedom isn’t the freedom to say literally anything in an academic forum. It’s the freedom to say anything with a sound methodological basis.”
While these ideas lacked scientific rigor, Sear explained, they were often not intended for other scientists. “Scientific racism really is not aimed at academia. It’s aimed at the outside world. And this, I think, is why it’s so often such bad science,” Sear said.
The appropriation of open science
The open science movement around this time also proved to boost the spread of flawed research on race, ethnicity, and genetics. Academic journals increasingly were publishing papers without paywalls, so anyone could access them, and often requiring the data underpinning research to be available.
Some scientists had also begun posting early drafts of their work, called “preprints,” on public forums. By doing science in the public square this way, people with explicit political agendas could access, manipulate, and reinterpret published research in a way that sometimes took academics by surprise.
Online, white nationalists used popular genetic testing websites to prove how white they were, and reanalyzed scientific data with a bent to affirming biological differences between races. They also seized on uncertainty among biologists about how to discuss race in the academic literature. Discussion forums on the subject might lean on anti-science conspiracy theories, but users could sometimes make sophisticated arguments about statistical uncertainties or the distinction between correlation and causation.
“They read both against and with the scientific literature, and that’s the way in which it becomes a very complicated dance that they sometimes make,” said Panofsky, who has studied the ways that far-right movements weaponize genetics.
The solution to the weaponization of genetics isn’t gatekeeping research, experts studying the issue agree. But, they say that academia hasn’t confronted the ways science can be used to embolden bigotry.
“We have basically a metric for how much Nazis like your research,” said Jedidiah Carlson, a population geneticist at Macalester University who led an analysis of how preprints circulate among right-wing extremists online. But it’s not a feature many are interested in. He wants to see researchers more attuned to the long-term impact of their work.
Incentive structures in research are also responsible for the continued popularity of research on topics like the links between genetics and intelligence or educational attainment, Carlson said. It’s “easy to get money for it, because you can say this has immediate policy implications for education and immigration policy … It’s just treated as this generic ‘apolitical’ research when it never has been.”
Challenging the idea that genes are ‘in the driver’s seat’
The failure to deeply engage with the dark history of eugenics and the way it’s informed a number of academic fields is linked to current political hostility directed toward immigrants, according to Marielena Hincapié, an immigration scholar and lawyer at Cornell University who hosted a symposium on the 100-year legacy of eugenics and the Immigration Act of 1924.
She points to recent attacks on immigrant communities carried out by people that believe in the Great Replacement Theory, a conspiracy that posits there is a concerted effort to diminish the power and influence of white people in the United States. The gunman behind one such attack, in Buffalo, New York, directly cited genetics research in his thinking.
The incident sparked some soul searching within the genetics community, which has also pushed back on problematic use of its research. In one case, a genetics consortium challenged the use of its data by a private company to screen embryos. On another occasion, a now-defunct app claimed it could test users on whether they had genes associated with same-sex sexual orientation, drawing on a paper published in Science. That prompted a protest petition signed by more than 1,600 scientists.
There’s also growing interest in the scientific community in how social determinants, such as economic policies, racism, and climate change, shape people’s health, and in the field of epigenetics, which studies how the environment affects gene expression. These paradigms open up an understanding that “genes are not necessarily in the driver’s seat, but they’re in an interactive relationship with a whole bunch of other factors,” said Panofsky. “They seem to open a door to a post-deterministic biology and genetics.”
Even so, the field has yet to truly rethink its buy-in of the idea that genes play a central role in people’s abilities and behaviors, Panofsky said. That thinking can inadvertently support the kind of problematic rhetoric Trump has applied to immigrants. While much of the U.S. has moved on and forgotten about its eugenic past, the country hasn’t done the work to refute the ideas it made so popular.
“We presume that we’ve done the work of rooting these matters out of our society,” said Michele Goodwin, a professor of constitutional law and global health at Georgetown Law. “But that presumption is proving to be quite thin and weak in these times.”
Just over 100 years ago, eugenicist Harry Laughlin testified before the U.S. House of Representatives that “The character of our civilization will be modified by the ‘blood’ or the natural hereditary qualities which the sexually fertile immigrant brings to our shores.” His argument wouldn’t be out of place today.