Eugenics: How “Improving Humanity” Became a Political Project

Eugenics is not only a Nazi history

Eugenics was a historical movement that sought to shape future generations by encouraging reproduction among people labeled “fit” and restricting reproduction among those labeled “unfit.” In practice this ranged from counseling and propaganda to marriage restrictions, institutionalization, and compulsory sterilization.

Nazi Germany radicalized eugenic ideas into an exceptionally violent racial-state project, but the movement did not begin with Nazism. Before 1933 it already had organizations, laws, and academic supporters in the United States, Britain, Germany, and elsewhere. Starting the story only with Hitler hides how ordinary institutions of science, medicine, and social policy can adopt a logic of biological ranking.

Francis Galton coined the term “eugenics” in 1883. He believed that many physical, mental, and social traits were strongly hereditary and that human populations might be improved in a manner analogous to selective breeding in animals. Modern genetics has shown many complex traits to emerge from many genes, environments, and their interactions, but Galton’s proposal was compelling in its time because it promised measurable social progress.

Eugenics therefore presented itself as a project for scientifically managing the future. Statistical measurement became joined to moral judgments about what kind of person should be desirable. That move from describing differences to ranking human value is one of the central transitions in the story.

Historically, “positive eugenics” generally meant encouraging reproduction among groups eugenicists judged desirable. “Negative eugenics” meant restricting reproduction among people labeled undesirable. Positive and negative here described two directions of population policy, not moral approval and condemnation.

The boundary was also blurred in practice. Better Babies and Fitter Families contests were less directly coercive than surgical sterilization, yet they still taught the public that reproduction could be scored, ranked, and steered according to an allegedly biological hierarchy.

The rediscovery of Mendelian inheritance around 1900 gave genetics a powerful experimental framework. Early eugenicists, however, often transferred simple inheritance models from traits where they worked well to complex phenomena such as intelligence, poverty, criminality, “morality,” and social success.

The problem was not that heredity is unreal, but reductionism: complex behavioral and social traits were frequently entered into pedigrees as if they were simple, stable, nearly Mendelian units. Environment, education, poverty, discrimination, and measurement error consequently received far too little weight.

Institutions make an idea durable

Eugenics did not remain a salon philosophy. The Eugenics Record Office was established at Cold Spring Harbor in 1910 and collected family pedigrees, questionnaires, and data on supposed hereditary traits. Similar networks connected universities, physicians, social agencies, charities, and legislators.

Once an idea moves into forms, archives, and administrative categories, it becomes much more powerful. A person is no longer merely the subject of a theorist’s opinion; they can become a file, a diagnosis, an institutional classification, and eventually the object of a legal order.

Eugenics was a transnational movement. International congresses, including the 1921 meeting in New York, brought together researchers, physicians, demographers, and political advocates. Such gatherings helped create the appearance of a modern and legitimate field of social science.

Institutional agreement, however, is not the same as truth. Eugenics is a powerful example of how networks of prestigious institutions can reinforce poor assumptions when measurement, social prejudice, and policy goals begin validating one another.

Better Babies and Fitter Families competitions became popular in the United States during the 1910s and 1920s. Children and families were measured, examined, and scored, while later competitions increasingly joined health assessments to pedigrees and allegedly hereditary character traits.

This reveals a softer side of eugenic policy: it does not necessarily begin with police. It can begin with a prize, an exhibition, a form, and social prestige. Yet the hierarchy remains—the question of which families represent the future and which should reproduce less.

Eugenic ideas intersected with marriage law, racial classification, and immigration policy. The U.S. Immigration Act of 1924 established national-origins quotas, sharply restricted migration from parts of Europe, and excluded immigrants from Asia; racial and eugenic arguments formed part of the broader political support for restriction.

It would be inaccurate to call every immigration or marriage rule purely eugenic. More precisely, eugenics supplied a biological vocabulary through which existing hierarchies of nation, race, class, and ability could be presented as scientific population management.

Indiana 1907: coercion becomes law

Indiana enacted the first U.S. state law mandating eugenic sterilization for certain people in state custody in 1907. The statute rested on the belief that criminality, “idiocy,” “imbecility,” and other undesirable characteristics were transmitted by heredity.

Sterilizations were halted in 1909, and the Indiana Supreme Court struck down the original law in 1921 for lack of due process. A new regime followed in 1927. Indiana matters because it shows how quickly eugenic language moved from theory into administration and irreversible surgical coercion.

Indiana did not remain an exception. By the early 1930s many U.S. states had enacted compulsory or involuntary sterilization laws. Their principal targets were people in state psychiatric hospitals, institutions for people with intellectual disabilities, prisons, and welfare systems.

This produced a pronounced class asymmetry. People with private resources could often avoid the institutional machinery, while poor, institutionalized, and socially marginalized people were more exposed to state reproductive policy.

California became the most active U.S. state in eugenic sterilization. Archival research indicates roughly 20,000 sterilizations in state institutions across the twentieth century, with substantial ethnic, gender, and class disparities.

California also matters internationally. German eugenicists followed American sterilization practice, and California appeared in discussions of large-scale feasibility. That is a documented connection; it is not evidence that the Nazi system can be reduced to a simple American export.

In Buck v. Bell, the U.S. Supreme Court in 1927 upheld a Virginia statute under which Carrie Buck was ordered sterilized. The decision became a legal symbol of the moment when the nation’s highest court accepted the proposition that the state could permanently alter an individual’s reproductive capacity in the name of an asserted public interest.

Later historical research exposed how deeply problematic the diagnoses and social labels applied to Buck and her family were. The case warns that formal procedure cannot cure injustice when the system’s basic categories are already built on false or discriminatory assumptions.

Who became “unfit”

Eugenic categories included disability, mental illness, epilepsy, poverty, criminality, sexual behavior, and ideas of “moral degeneracy.” Some of these have biological components; others are primarily social classifications. Eugenic regimes often collapsed them into one hereditary narrative.

Because institutions applied these classifications under conditions of unequal power, they were not distributed neutrally. Women, poor people, immigrants, racial minorities, disabled people, and residents of institutions were often more exposed than people with the social standing and resources to resist.

For part of the eugenics movement, population improvement was explicitly tied to claims of white or “Nordic” superiority. Other advocates spoke more about health, intelligence, dependency, or social cost. The movement was not ideologically uniform, but racism cannot be reduced to an irrelevant fringe.

Nor is it enough to describe eugenics as nothing but racism in a laboratory coat. Its power came from the combination of racial and class hierarchy, ableist prejudice, hereditary determinism, demographic anxiety, and the genuine prestige of modern science.

Sterilization and eugenic programs also operated in Canada, Scandinavian countries, and elsewhere. They differed in law, purpose, duration, and degree of coercion. It is therefore misleading to imagine one global program with a single command center.

It is accurate, however, to speak of an international field of ideas. Specialists read one another, attended congresses, compared legislation, and translated models into local political contexts. A transnational history does not require a secret headquarters; documented exchange is enough.

German racial hygiene developed before the Nazi seizure of power and had its own academic, medical, and nationalist roots. After 1933 the Nazi state incorporated these ideas into a totalitarian project in which hereditary policy and racial antisemitism fused with a coercive state apparatus.

This is a crucial boundary against the simple import myth. American and German eugenicists were connected and Germans studied American laws, but the Nazi system was not a copy of one foreign statute. It was a distinctive radicalization within a specific political regime.

The German law of 1933

On 14 July 1933 Nazi Germany enacted the Law for the Prevention of Offspring with Hereditary Diseases. It mandated sterilization for people with a list of diagnoses the regime treated as hereditary, ranging from certain mental illnesses to deafness, blindness, and “severe alcoholism.”

An estimated 400,000 people were forcibly sterilized under the system. A network of hereditary-health courts, physicians, and institutions implemented it. Eugenics thus became routine state medicine and law rather than propaganda at the margins.

Historical evidence shows that German eugenicists knew American sterilization laws and literature; California was cited, and Harry Laughlin produced an influential model sterilization law. American and German experts also met within international professional networks.

None of this means that the United States “created Nazism.” Nazi racial policy combined eugenics with antisemitism, imperialism, nationalism, dictatorship, and a genocidal project. The transatlantic connection matters precisely because it can be documented without exaggeration.

Nazi physicians and officials also used eugenic reasoning in programs that killed disabled and mentally ill people, especially Aktion T4. The idea that lives could be ranked by biological and social “value” helped create an institutional vocabulary for exclusion and destruction.

Genocide should not be presented as the automatic, inevitable final stage of every eugenic policy. The Holocaust had a specific antisemitic, racial, imperial, and totalitarian ideology. A stronger conclusion is that eugenics can provide dangerous tools of classification when joined to dehumanization and unchecked state power.

The history of Nazi medicine shows active participation by parts of the medical profession in sterilization, “euthanasia,” and experimentation. In the United States as well, physicians and administrators of state institutions played central roles in recommending and performing sterilizations.

This matters for institutional responsibility. Expertise can constrain political arbitrariness, but it can also legitimize it when a profession adopts a political objective and translates it into diagnoses, forms, and procedures.

Why call it pseudoscience if real scientists participated?

Eugenics did not consist solely of fake laboratories. It used genuine statistical methods, pedigrees, medical examinations, and emerging genetics. The failure lay in inference: complex and poorly defined social traits were treated as stable hereditary units, while value judgments were concealed inside the language of measurement.

“Pseudoscience” is therefore useful only if it does not become an excuse for easy distance. The danger is not merely obviously fake science; it also lies in real methods applied beyond what they can establish, and political values presented as biological facts.

In 1942 the U.S. Supreme Court in Skinner v. Oklahoma invalidated a law mandating sterilization for certain repeat offenders on equal-protection grounds. The Court emphasized the gravity of procreation as a basic civil right and the irreversible nature of sterilization.

Skinner did not simply erase Buck v. Bell, nor did it end eugenic sterilization overnight. Legal and institutional regimes changed unevenly, and in some states the practice continued for decades.

Nazi crimes severely discredited the word eugenics, yet sterilization programs in the United States continued in some places. In North Carolina, more than 70 percent of the people sterilized under the state program were sterilized after 1945. California’s legal framework likewise persisted deep into the twentieth century.

This disrupts the comforting story that the world saw the error in 1945 and immediately changed course. Institutions have inertia. Once a practice is embedded in welfare agencies, hospitals, and law, a new moral climate can weaken it without instantly removing it.

After the Second World War, the Nuremberg Code, the Universal Declaration of Human Rights, and later bioethical and human-rights instruments increasingly placed individual dignity, consent, and equality at the center. The Genocide Convention also included measures intended to prevent births within a protected group among the acts that can constitute genocide when accompanied by the required intent.

This did not solve every old problem. It did change the normative starting point: state and profession must justify interventions into an individual’s body, rather than requiring the individual to justify their existence before a plan for a “better population.”

Disability and reproductive autonomy

Disabled people were among the principal targets of historical eugenic programs. Contemporary human-rights law therefore expressly protects the right of persons with disabilities to family life, to decide the number and spacing of their children, and to retain fertility on an equal basis with others.

This does not prohibit medicine that treats disease or reduces suffering. It does demand caution when the value of a person begins to be equated with genetic “quality,” or when social support is replaced by the idea that it would be preferable to prevent certain kinds of people from existing.

Not every decision involving genetics is eugenics. Three elements are especially important to the historical core of the concept: ranking people or future people by hereditary traits, an aim of altering the composition of a population, and institutional or state power to encourage, restrict, or impose that reproductive selection.

Coercion can be direct, such as an operation without free consent, or indirect, such as loss of support, institutional dependency, or a system in which some reproductive choices are effectively unavailable. The type and degree of coercion matter historically; not all forms of choice are equivalent.

Genetic counseling, voluntary testing, treatment of hereditary disease, somatic gene therapy, and an individual reproductive decision are not eugenic by themselves. They can be practiced within a framework of patient interest, informed consent, and nondiscrimination.

The comparison becomes stronger when there is a policy of selection, pressure directed at particular groups, institutional definition of “desirable” traits, or an aim of reshaping a population. Without such steps, the term eugenics becomes so broad that it can no longer distinguish treatment from a political project.

Contemporary genomics understands polygenic traits, pleiotropy, population differences, environmental effects, and limits of prediction far better than early eugenics did. Medical genetics also operates inside legal and ethical frameworks built in part from the memory of historical abuse.

More knowledge does not remove the normative question. Even a highly accurate prediction does not tell society whether it should be used to choose future people. “Can” does not imply “ought,” and a statistical difference does not create a hierarchy of human worth.

Genome editing: therapy, heredity, and future generations

The World Health Organization distinguishes somatic genome editing that can treat disease in an individual from heritable editing whose changes could pass to descendants. It therefore calls for stronger governance and recognizes substantially greater ethical concerns around heritable applications.

Eugenic history is a warning here, not an equation. Treating sickle-cell disease in a consenting patient is not the same as a state program to reduce births within a group. The comparison moves closer to historical eugenic terrain when therapy becomes the design of preferred inherited traits and when choice becomes social pressure or institutional policy.

Preimplantation genetic testing for monogenic disease has a different evidentiary and ethical profile from selecting embryos by polygenic scores for complex diseases or traits. In the latter case predictions are statistical, population-dependent, and constrained by the small number of embryos actually available for selection.

The American Society for Reproductive Medicine has recently stated that polygenic embryo testing for complex disorders is not ready for clinical use and should not be used for nonmedical trait selection. That is a useful reminder not to describe present technologies as more capable than they really are.

Historical eugenics teaches most clearly about state and institutional power, while contemporary technologies also raise questions about markets. If trait selection becomes a commercial service, advertising, status competition, insurance, and unequal access could create pressure even without formal compulsion.

That is not proof of a new eugenics. It is a reason to examine the structure around individual choice: who defines desirable traits, who can pay, who is excluded, and whether people retain a realistic right not to participate.

Five warning signs

An analogy with eugenics becomes especially well grounded when several features converge: hereditary ranking of people, a hierarchy of “better” and “worse” lives, reproductive selection, institutional or economic coercion, and an aim of changing a population. No single feature is sufficient by itself.

This framework is more useful than historical name-calling. Instead of instantly branding a new technology eugenic—or dismissing the analogy in advance—we can ask which concrete mechanisms of the old system are actually being reproduced.

UNESCO’s human-genome framework emphasizes that a person’s dignity and rights do not depend on genetic characteristics and that individuals must not be reduced to their genome. This directly reverses the eugenic logic that often treated people primarily as carriers of desirable or undesirable hereditary material.

Science can describe risk, inheritance, and probability. Society must separately decide how to prevent statistical description from becoming permission for discrimination or coercive reproductive policy.

The greatest danger of history is not that it returns with the same uniforms and vocabulary. More often a structure of reasoning returns: a social problem is translated into biology, a population is divided into desirable and undesirable, technique acquires moral authority, and the individual becomes a means to a future collective goal.

This article therefore does not offer the equation “genetics = eugenics” or “transhumanism = Nazism.” It asks a harder question: when does care for health become power over who should be born, what they should be like, and who gets to set the standard?

Eugenics becomes political when descriptions of heredity are turned into permission to rank human worth and manage other people’s reproduction.