Personal biases held by physicians and others in the field of healthcare continue to affect patients of all kinds. These can be biases about specific diseases or treatments or biases about the patients themselves.

Pain management is one area in which racial disparities have been widely documented but haven’t been fully understood. A new study published in PNAS indicates that incorrect beliefs about racial differences cause white doctors and medical students to make less-appropriate pain-treatment recommendations. In short, black patients may be getting short-changed on pain management if their doctors think that black bodies are inherently stronger than white bodies.

To study the phenomenon of racial bias in pain treatment, the researchers conducted two studies. They first examined the beliefs of whites who were not medical professionals to establish baseline prejudices about pain perception for people of different backgrounds. They found that white adults with no medical training endorse at least some false beliefs about biological differences with black people, including the incorrect belief that blood coagulates at different speeds for people of different races.

They also found that among white participants, there was a racial difference in participants’ perceptions of others’ pain, particularly among those who held other incorrect beliefs about the biological differences between races. This bias was fueled by the pervasive belief that a black body is inherently stronger and a white body inherently weaker.

Having established these racial biases in non-medical professionals, the researchers went on to investigate whether they influenced evaluations of pain perception when black patients are treated by white doctors.

When white medical students and medical residents were asked similar questions, the researchers got the same results. For medical professionals who held many false beliefs about biological differences between the races, the racial bias in pain perception appeared again—they rated the pain of black patients as “less painful” compared to that of white patients.

This bias carried over into their treatment recommendations. Doctors and medical students who held more false beliefs about biological racial differences also recommended less-appropriate treatment for black patients, likely due to their incorrect perceptions of these patients’ experiences of pain.

In contrast to this, when white doctors and medical students had a more realistic grasp on biological differences, they showed the reverse effect. These participants were more likely to rate the pain of white patients as “less painful” than that of black patients. However, these participants did not show any bias in their treatment recommendations.

We know there’s a large racial disparity in pain management, both in terms of patient treatment and outcomes. This paper shows that these disparities may be due to fantastical beliefs about biological differences between people from different racial groups and that these beliefs persist even among highly educated medical professionals.

As such, the paper illustrates the need for diversity awareness training in medical education. It could help doctors to examine their own biases and ensure that patients of all races are receiving the appropriate treatment.

PNAS, 2016. DOI: 10.1073/pnas.1516047113, (About DOIs).