African Americans are routinely under-treated for their pain compared with whites, according to research. A study released Monday sheds some disturbing light on why that might be the case.

Researchers at the University of Virginia quizzed white medical students and residents to see how many believed inaccurate and at times “fantastical” differences about the two races — for example, that blacks have less sensitive nerve endings than whites or that black people’s blood coagulates more quickly. They found that fully half thought at least one of the false statements presented was possibly, probably or definitely true.

Moreover, those who held false beliefs often rated black patients’ pain as lower than that of white patients and made less appropriate recommendations about how they should be treated.