DURHAM, N.C. – The Black-white health gap is one of the most striking examples of the depths of racial inequality in the United States. Why does it persist? A new paper from researchers at the Samuel DuBois Cook Center on Social Equity at Duke University investigates—and refutes—a popular argument for the causes of this disparity.
“How Epigenetic Inheritance Fails to Explain the Black-White Health Gap” explores the hypothesis that the trauma of slavery inflicted upon the enslaved population in the U.S. precipitated epigenetic changes that have been passed down and persist to the present.
This argument, labeled as Post-Traumatic Slavery Syndrome or Post-Traumatic Slavery Disorder, postulates that these inherited changes at the genetic level are negatively affecting the health of contemporary African Americans.
“Blaming the inherited trauma of slavery for modern health disparities is inaccurate, imprecise and irresponsible,” said public policy professor William A. Darity Jr., co-author of the paper who directs the Samuel DuBois Cook Center at Duke. “All that Black Americans have ‘inherited’ is a perpetual resource disadvantage in a society that refuses to enact policies to correct the condition.”
The paper will be published in the February 2025 issue of Social Science & Medicine and is now available online.
Many statistics underscore the depths of the racial health gap: Black life expectancy for many years has averaged four years less than white life expectancy, a gap that expanded during the COVID-19 pandemic. Black infant mortality is twice as high as that of white infants, and Black mothers are three times as likely as white mothers to die of pregnancy-related causes.
The consensus understanding of the cause of these gaps is they are the product of historical and ongoing systemic racial disparities. The Black-white health gap stems, at least in part, from the racial wealth gap — the 2022 Survey of Consumer Finances, collected by the Federal Reserve, found that the average white household had more than a million dollars more in wealth than the average Black household — coupled with disparate access to land and housing, well-paid employment, quality education, adequate sanitation, nutrition and medical care.
However, in recent decades the transgenerational slavery trauma hypothesis has gained prominence. This argument suggests that the extreme injuries inflicted upon the enslaved in the United States have been transmitted across multiple generations, resulting in poorer mental and physical health for their living descendants.
“It is romantic to say that the trauma stemming from these atrocities is in our genes,” says Darity, a leading scholar of black reparations in the U.S. who is also a professor of African and African American Studies and economics.
“But this framing is dangerous since makes these problems seem more intractable than they are, when they can, in fact, be addressed by changing the material conditions Black Americans experience today.”
In the paper, the authors emphasize that there is no direct evidence for the transgenerational trauma hypothesis: There is no data spanning the five-plus generations to the period of U.S. slavery. Moreover, as free and enslaved blacks both experienced racialized trauma, there is not a valid control group to isolate the effects of the trauma of enslavement.
The authors then proceed to review the studies often invoked in indirect support of the transgenerational trauma hypothesis. The authors note, intergenerational epigenetic transmission has been demonstrated in laboratory animals but not in humans. The human studies invoked typically analyze the effects of Holocaust-induced trauma in subsequent generations, or the effects of grandparental food consumption on the health of grandchildren.
However, in parsing these studies, the authors find “no evidence of a pathway five or more generations, the minimum to attribute modern-day outcomes to slavery-era trauma.”
Moreover, given the persistence of discrimination in the country, they find the transgenerational trauma argument unnecessary, as it does not explain anything that is not already explained by “ongoing exposure to a day-to-day trauma-inducing environment.”
The authors conclude by stating the need for clarity around these arguments, especially as discussion around Black reparations continues to grow. Only precise arguments can help identify the proper causes — and enable the necessary solutions.
“There are many good arguments for pursuing Black reparations, or similar policies to promote racial equity,” says Darity, “but this is not one of them.”
CITATION: Charney, Evan, William A. Darity, and Lucas Hubbard. 2025. “How Epigenetic Inheritance Fails to Explain the Black-White Health Gap.” Social Science & Medicine 366 (11): 117697. doi: 10.1016/j.socscimed.2025.117697.