Racial Biology and Medical Misconceptions

In 2016, Hoffmann et al. documented persistent racial misconceptions among medical students and residents.1 The authors showed a series of statements regarding biological differences between groups described as “Black” and “White” to three groups of “White” people: participants without medical training, medical students from the University of Virginia (UVA) and UVA residents. . Participants were asked to determine whether statements such as “black skin is thicker than white skin” were true or false; in this example, 58% of the lay audience and 25-42% of medical students and AVU residents answered “true”. The study showed that multiple false beliefs were held by the public and medical trainees, and it was widely praised for bringing attention to this issue.

A closer reading of the article, however, reveals the true depth of the challenge: throughout the introduction and discussion, the terms “Black” and “White” are used as if they were referring to real biological entities. , and not to the groups socially defined by these terms. actually identify. Herein lies the biggest racial misconception still prevailing in the medical community: socially defined races continue to be viewed as if they accurately reflect biological variation within our species (see sidebar for more). more). Socially defined racial categories are based on several characteristics in addition to genetic ancestry, including physical appearance, culture, language, and religion. They are historically contextual, so definitions of “blackness” in America vary by region and over time: in 1910 Alabama you were defined as Negro if you had only one great-grandparent of ancestry African, while in Michigan, two great-grandparents grandparents were the rule. In the Caribbean, any European ancestry was enough to define someone as white. The Amerindian “race” is defined by the cultural criterion of belonging to a tribe; race may change depending on affiliation.

Further reading on medical misconceptions about race.

  • Amutah C, Greenidge K, Mante A, et al. Distorting race – the role of medical schools in spreading physician bias. N Engl J Med 2021;384:872-8.

  • Fan S, Hansen MEB, Lo Y, Tishkoff SA. Going global by adapting locally: a review of recent human adaptation. Science 2016;354:54-9.

  • Graves JL. Biological theories of race beyond the millennium. In: Suzuki K, von Vacano DA, eds. Reconsidering Race: Social Science Perspectives on Racial Categories in the Age of Genomics. New York: Oxford University Press, 2018: 21-31.

  • Graves JL. Viewing the World Through Colored “Race” Glasses: The Determination Bias Fallacy in Biomedical Research and Practice. In: Gómez LE, López N, ed. Mapping “race”: critical approaches to health disparities research. New Brunswick, NJ: Rutgers University Press, 2013: 39-52.

  • Kaufman JS, Merckx J, Cooper RS. Use of racial and ethnic categories in medical tests and diagnoses: primum non nocere. Clin Chem 2021;67:1456-65.

  • Li A, Deyrup A, Graves JL, Ross L. Race in reading: problems in pediatrics (the “work”). Acad Med (in press).

  • Loring Brace C. “Race” is a four-letter word: the genesis of the concept. Oxford and New York: Oxford University Press, 2005.

  • Stephenson GT. Racial Distinctions in American Law. New York and London: D. Appleton, 1910.

In the 20th century, bio-anthropological and population genetic analyzes of human variation demonstrated conclusively that anatomically modern humans do not have biological races. Since human biological variation is driven by genetic drift (random variation in allele frequency associated with ancestral lineages) and uncorrelated selection pressures, physical traits cannot be used to delineate racial groups. Traits such as skin color, tooth size, bone density, presence of hemoglobin S, and craniofacial measurements do not correspond to socially defined racial categories.

The challenge of population mixing further complicates the issue of socially defined race: Due to chattel slavery and colonialism in America, people of primarily African descent and groups included in the “Hispanic” ethnic category come from multiple ancestries with substantial regional variations. For example, although the average proportion of European ancestry among African Americans is around 16%, the proportion exceeds 30% in some states.2 Additionally, a growing number of people socially defined as “black” in the United States come from various African nations. These individuals have little or no European admixture. Finally, although populations differ in the frequency of alleles that can predispose people to a given disease, no population is disease free. The focus on disease associations with particular populations, reinforced by “classic” test questions and vignettes, risks delaying diagnosis and leading to inadequate care.

The modern science of human biological variation is not well understood by biomedical scientists and clinicians, and such material is generally not required in undergraduate programs or medical training – hence the persistence of racist assumptions in medicine. Epidemiological data is fundamental to the preclinical program: since diverse populations are affected by various disease states in varying proportions, educators describe most disease entities in terms of gender ratio among affected patients, typical age early and often associations with socially defined diseases. races. Historically, these associations do not take into account the cultural and social determinants of health, such as poverty and access to care. Although some institutions attempt to correct the frame of presentation of race, deeper questions regarding the validity of scientific knowledge regarding human biological variation still require careful attention.

Linking socially defined race to disease is rarely neutral and has a long history. Take, for example, the frequently cited association between keloids and African ancestry. According to UpToDate, “keloids have been reported in 5-16% of people of Hispanic and African descent.”3 The cited reference is a review article that does not provide experimental data; the upper limit, 16%, is derived from a published, but not peer-reviewed, discussion at a 1931 dermatology meeting that cited observations of Congolese miners. Interestingly, at this same meeting, a researcher (Naegeli) reported that a population-based study of Swiss adults found that 13.3% had keloids. The clinical relevance of this disparity (16% vs 13.3%) is questionable. Of note, in October 2021, Dr. Deyrup provided the authors of the UpToDate article on keloids with data demonstrating the weak association between socially defined race and keloid formation; in January, the sentence quoted above was deleted. However, as of January 19, 2022, the association between socially defined race and keloids is retained in the genetics section of the article.

The Racialization of Disease Spreads in Textbooks and is Reinforced by Medical Licensing Examinations and the Test Prep Industry: A 2011 Evaluation of the 8th Edition of Robbins and Cotran Pathological Basis of Diseasea widely used medical school textbook, found that of 31 statements linking African ancestry to the disease, 17 could not be confirmed by the literature and 3 were directly contradicted (related to squamous cell carcinoma, malignant tumors of the liver and biliary tract, and malignant hypertension and accelerated nephrosclerosis).4 In 2017, a review of the use of race and ethnicity in UWorld Step 1 QBank, a popular test preparation resource, showed variations depending on whether a racial or ethnic descriptor was central to interpretation. correctness of a question or simply incidental: while the descriptor “White/Caucasian” was central in only 7.4% of the questions, for Native Americans, race was “diagnostic” 100% of the time.5

So how do you solve this deep-rooted problem? To assess the validity of scientific data, physicians need a better understanding of modern science of human biological diversity. We believe that a course in biological anthropology focusing on this subject should be highly recommended for admission to medical school, and that the medical college admission test should assess basic knowledge of human biological variation. and social definitions of race. For programs that decide not to follow a course requirement, a reading list on human biological variation and its discordance with socially defined race could be compiled. As others have argued, the preclinical curriculum needs to reinforce understanding of socially defined concepts of race versus biological ones – perhaps in the courses that many medical schools now offer on race disparities. health.

Given the long history of racialization in medicine, continued education about human biological variations and diseases will be needed to correct generations of misinformation. Symposia and overview presentations on the cultural determinants of health disparities, the puzzling contributions of population mixing, and the potential harm of associating a socially defined race with disease entities will help physicians eliminate “racial glasses” through which they see patients first and help them focus on finding more meaningful underlying diagnoses. Publishers and authors of textbooks should carefully assess the scientific validity and clinical relevance of their material.4

Ultimately, medical trainees will model what they see in their instructors and referring physicians. We suggest that such a step change is a crucial step towards the eventual adoption of individualized medicine, in which clinicians appreciate actual causal factors in order to better tailor care to patients.

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