The New Science of Biosocial Race
"In a 2024 kidney transplant breakthrough, Dia'Londa Bagley received a lifesaving organ after hospitals abandoned a race-based formula that had for years systematically underestimated the severity of kidney disease in Black patients 6 ."
For decades, science has presented us with a paradox. On one hand, geneticists have proven that race, as we commonly understand it, has no biological basis. There are no genes unique to any racial group, and the vast majority of human genetic variation exists within, not between, populations 2 .
Postgenomic science has stirred new interest in the long-standing debate over the relationship between the biological and the social 1 .
Yet on the other hand, physicians observe stark health disparities along racial lines: Black Americans are more than three times likelier than white Americans to experience kidney failure, and often face different risks for conditions ranging from heart disease to maternal mortality 6 .
This paradox is dissolving thanks to a revolutionary new field of research exploring what scientists call "biosocial race"—the complex ways in which social processes of racialization become biologically embodied, affecting our health and even shaping our physiology across generations 1 .
Why genetic science rejects race as a biological reality
To understand the biosocial perspective, we must first dismantle a persistent myth: that racial categories reflect deep biological differences. The concept of biological race has been thoroughly debunked by modern genetics. As one educational initiative plainly states, "Race isn't biological" 2 .
From a genetic perspective, using skin color to categorize people is as arbitrary as differentiating people by which end of a boiled egg they crack open 2 .
Richard Lewontin's seminal 1972 analysis demonstrated that approximately 85% of human genetic variation exists within any local population .
The evidence against biological race is overwhelming. Richard Lewontin's seminal 1972 analysis demonstrated that approximately 85% of human genetic variation exists within any local population, with only about 15% distinguishing different populations . Subsequent studies have consistently reinforced this finding.
A massive 2024 NIH study analyzing the genomes of more than 200,000 participants in the "All of Us" cohort provided more definitive evidence than ever before that Americans' self-reported race is a poor proxy for their genetic ancestry 4 . The study found that socially defined groups don't map neatly onto genetic ancestry, revealing a much fuzzier understanding of race than the distinct categories we often imagine 4 .
"There are no races, there are only clines"—referring to the gradual geographic gradients of genetic variation that don't correspond to sharp racial boundaries .
| Level of Analysis | % of Genetic Variation |
|---|---|
| Within local populations | ~85% |
| Between continental populations | ~15% |
Vast majority of human genetic diversity exists within any local population .
The mechanics of biosocial embodiment
If race isn't biological in a genetic sense, how do we explain the persistent health disparities along racial lines? The answer lies in understanding how social experiences—particularly the stress of racial discrimination—can biologically embed itself in our bodies through specific physiological pathways.
One key mechanism involves epigenetics—molecular modifications to DNA that regulate how genes are expressed without changing the genetic sequence itself 1 .
Research has shown that psychosocial stress and trauma resulting from racial discrimination can lead to epigenetic changes in gene-expression patterns 1 .
For example, studies by Kuzawa and Sweet have demonstrated how chronic stress from racism can create epigenetic patterns that affect cardiovascular health and even birth outcomes in the next generation 1 .
Another fascinating pathway involves the human microbiome—the trillions of bacteria that inhabit our bodies and play crucial roles in our health.
Research has revealed that social and environmental factors associated with racialization can significantly shape our microbial communities 1 .
Your microbiome is influenced by your diet, environment, stress levels, and even the buildings you inhabit—all of which are shaped by social and economic factors that often correlate with racial identity due to structural inequities 1 .
| Pathway | Mechanism | Health Impact Examples |
|---|---|---|
| Epigenetics | Social experiences causing chemical modifications that regulate gene expression | Intergenerational effects on birth weight, cardiovascular disease risk 1 |
| Microbiome | Social and environmental factors shaping our microbial communities | Variations in immune function, metabolic health 1 |
| Chronic Stress | Sustained cortisol and inflammation from experiencing discrimination | Increased risk of hypertension, diabetes, premature aging 6 |
Removing race from kidney function equations
For decades, medical laboratories used a race-based equation to estimate kidney function. The test measured creatinine, a waste product released from muscles, but incorporated a "correction factor" for Black patients based on the incorrect assumption that they inherently have higher muscle mass 6 .
This meant Black patients were often judged to have less advanced kidney disease than non-Black patients with the same creatinine levels, delaying their eligibility for life-saving transplants 6 .
Reviewing physiological studies on muscle mass and creatinine metabolism across different populations 6
Assessing how the race coefficient affected transplant waiting lists and health outcomes 6
Creating new estimation formulas that didn't incorporate racial categories 6
Medical institutions across the country, including Johns Hopkins, adopted the new race-neutral equations in 2022 6
The change had immediate, life-altering consequences. With the race modifier removed, many Black patients were reclassified into more advanced stages of kidney disease, properly positioning them on transplant waiting lists 6 .
Dia'Londa Bagley, who received her kidney transplant in June 2024, would likely have remained ineligible for a transplant under the old race-based system 6 .
As her physician, Dr. Derek Fine, noted, for someone on dialysis, getting a transplant "triples your life expectancy" 6 .
This case exemplifies how erroneously treating race as a biological category can have dire consequences.
| Metric | Before Race-Neutral Equation | After Race-Neutral Equation |
|---|---|---|
| Assessment of kidney function | Overestimated for Black patients | More accurate for all patients |
| Transplant eligibility | Delayed for Black patients | Appropriate timing for Black patients |
| Basis of calculation | Partially based on disproven assumption about race and muscle mass | Based on individual physiological measures |
Key concepts and methods in biosocial research
The ability to discern how social, political, and economic structures directly impact clinical interactions and health outcomes 6 . Medical educators are now integrating this into curricula to help future physicians understand health disparities.
An approach that moves beyond simply using racial categories as proxies and directly studies how racism—rather than race—affects health 3 . This means explicitly measuring experiences of discrimination, residential segregation, and other manifestations of structural racism.
Recognition that health disparities are transmitted across generations not through genes, but through "the legacies of inherited wealth, inherited environments that vary in their amenities, opportunities and resources, and other inherited factors through which the experiences of parents affect the physiology of offspring" 2 .
The anthropological perspective that recognizes "race becomes biology through the embodiment of social inequality" . This approach doesn't see biology and culture as separate domains, but as deeply intertwined.
From fixed categories to fluid processes
The emerging science of biosocial race requires us to fundamentally rethink what race is—its ontology, or fundamental nature. Traditional debates about race have generally fallen into three camps: those who see race as biological, those who see it as purely social, and those who argue that if race isn't biologically real, we should abandon the concept altogether 1 .
The biosocial perspective challenges all these positions by revealing a more complex picture. As Chellappoo and Baedke argue, "the emerging picture of a shifting landscape of entanglement between the social and the biological requires us to increase the complexity of our ontologies of race, or even embrace a deflationary metaphysics of race" 1 .
The science of biosocial race represents a paradigm shift in how we understand human difference. It offers a way out of the old, unproductive debate between those who would biologicalize race and those who would deny its material impacts on health and physiology. As one researcher aptly summarizes, race is best understood as a "culturally constructed label that crudely and imprecisely describes real variation" .
This new understanding has profound implications. For researchers, it means developing more sophisticated methods that directly measure the specific social and environmental factors affecting health, rather than using racial categories as crude proxies 3 5 . For physicians, it means abandoning race-based clinical algorithms that can cause harm, as exemplified by the successful removal of race from kidney function equations 6 .
"There is no biological basis to race... Society determines that. A lot of people have been concerned that we were using this social construct of race in a way that had biologic consequences" 6 .
For all of us, it means recognizing that while race may be a social construct, its effects can be powerfully biological—and that by changing the social conditions that produce health disparities, we can create a biologically healthier society for everyone.
The challenge before us is to build what the National Academies of Sciences, Engineering, and Medicine calls a "racism-conscious" approach to research 3 —one that acknowledges the reality of racial inequality without reinforcing biological essentialism.
As this science continues to evolve, it promises not only to transform medicine and research, but to fundamentally reshape our understanding of how society becomes biology, and how we might intervene to create a more equitable biological future.