Previous research by Amy Krosch, assistant professor of psychology in the College of Arts and Sciences, has shown that white people who identify themselves as political conservatives tend to have a lower threshold for seeing mixed-race Black and white faces as Black.

More often than liberals, Krosch found, white political conservatives show a form of social discrimination termed “hypodescent” – categorizing multiracial individuals as members of the “socially subordinate” racial group.

In new research published Feb. 22 in Philosophical Transactions of Royal Society B, Krosch used neuroimaging to show that this effect seems to be driven by white conservatives’ greater sensitivity to the ambiguity of mixed-race faces rather than sensitivity to the Blackness of faces; this sensitivity showed up in a neural region often associated with affective reactions.

Taken together, these study results suggest white political conservatives might overcategorize mixed-race faces as Black, not because of an aversion to Blackness, but because of an affective reaction to racial mixing more generally, Krosch said. The study appears in a special issue about political neuroscience.

“We knew from our previous work that conservatives tend to categorize more mixed-race faces as their ‘socially subordinate race, or according to hypodescent,” Krosch said, “a principle closely related to notorious ‘one-drop’ rules, used to subjugate individuals with any nonwhite heritage by denying them full rights and liberties under the law from the earliest days of American slavery through the Civil Rights Era.”

In the new study, Krosch said, she and the other researchers wanted to figure out why this is the case: “Specifically, we wanted to know if conservatives and liberals differ in the way they are literally seeing, thinking, or feeling…