Summary: Researchers identify how activity in the anterior insula contributes to the way political ideology shapes perception of race.
Source: Cornell University
How does political belief shape the way people perceive race?
Previous work by Amy Krosch, an assistant professor of psychology in the College of Arts and Sciences, showed that White people who identify as politically conservative are more likely than liberals to classify racially ambiguous, mixed Black–White faces as Black. This tendency—known as hypodescent—assigns multiracial individuals to the socially subordinate group.
In a new study published Feb. 22 in Philosophical Transactions of the Royal Society B, Krosch and colleagues used functional magnetic resonance imaging (fMRI) to explore why conservatives are more likely to apply hypodescent. Their findings suggest the effect is driven less by a heightened sensitivity to Black facial features and more by a stronger affective response to racial ambiguity. That response shows up in a brain region commonly tied to emotional processing: the anterior insula.
Taken together, the results indicate that White conservatives’ tendency to classify mixed-race faces as Black may stem from an aversion to racial ambiguity itself rather than from an explicit aversion to Blackness. The study appears in a special issue focused on political neuroscience.
“Our earlier work established that conservatives more often apply hypodescent,” Krosch said, “a classification pattern historically related to ‘one-drop’ rules that helped deny full rights to people with nonwhite ancestry. In this project, we wanted to know whether the difference between conservatives and liberals arises in perception, cognition, or emotion—do they literally see mixed-race faces differently, think about them differently, or feel differently about them?”
Mixed-race faces present at least two distinct stimuli: racial prototypicality (the degree to which a face looks more stereotypically Black or White) and racial ambiguity (how difficult it is to categorize the face). In behavioral studies these dimensions can be hard to separate. Neuroimaging offers a way to identify neural signatures associated with sensitivity to either feature, which can shed light on how political ideology relates to hypodescent.
The research team recruited 41 self-identified White participants who reported their political ideology on an 11-point scale before undergoing fMRI. While brain activity was recorded, participants classified computer-generated faces that varied from 100% White to 100% Black in 10% increments. The study examined which neural regions responded to Blackness and which responded to ambiguity, and how those responses differed by ideology.
The anterior insula was a central focus because prior studies link it to emotional and ambiguity processing, as well as to ideological differences. The insula plays a role in affective reactions and in signaling uncertainty, so variation in anterior insula activity could reveal whether conservatives’ bias relates to emotion-driven responses to ambiguity rather than altered visual perception or deliberative thought.
The imaging results showed that participants who reported more conservative political views had a lower threshold for labeling mixed-race faces as Black. Crucially, conservatives exhibited greater anterior insula activation in response to racially ambiguous faces. They also made categorizations more quickly than liberals. Together, these findings suggest conservatives may have a stronger affective reaction to ambiguity, prompting faster, more categorical decisions that align with culturally familiar, hierarchy-affirming classifications—namely hypodescent.
Importantly, conservatives and liberals did not differ in neural responses tied to low-level visual processing or broader social-cognitive regions when responding to Blackness or ambiguity. This pattern indicates the difference lies not in basic visual perception or deliberate social reasoning but in an affective response to ambiguity: conservatives may maintain a stricter boundary around whiteness because of how racial ambiguity makes them feel.
These findings advance our understanding of how political ideology influences race categorization. By revealing a neural mechanism—heightened anterior insula sensitivity to ambiguity—that links conservatism to hypodescent, the study provides insight into why multiracial people are often assigned to their most subordinate group, a categorization that increases their vulnerability to discrimination and contributes to persistent racial inequalities.
“Because minority-group categorization has wide-reaching social consequences and affects many people, it is critical to understand how ideology can reinforce racial hierarchies,” Krosch said. The study highlights an emotional pathway by which ideology can shape perceptual and social outcomes.
About this neuroimaging research news
Source: Cornell University
Contact: Gillian Smith – Cornell University
Image: The image is in the public domain
Original Research: Closed access. “The neural basis of ideological differences in race categorization” by Amy R. Krosch, John T. Jost and Jay J. Van Bavel. Philosophical Transactions of the Royal Society B
Abstract
The neural basis of ideological differences in race categorization
Multiracial individuals are frequently categorized into their socially subordinate racial group, a pattern known as hypodescent. Prior research indicates that political conservatives are more likely than liberals to demonstrate this bias. What remains unclear is how ideology shapes categorization: do conservatives and liberals literally see mixed-race faces differently, do they think about them differently, or do they have different affective responses?
To address these questions, a politically diverse sample of White participants categorized mixed Black–White faces as Black or White during fMRI. The study tested sensitivity to Black prototypicality (features associated with Black appearance) versus racial ambiguity (difficulty of categorization). Results showed that conservatism correlated with greater anterior insula activation to ambiguous faces, and that this neural response mediated conservatives’ tendency toward hypodescent. In other words, heightened sensitivity to racial ambiguity—rather than to Black prototypical features—appears to drive greater categorization of mixed-race individuals into the subordinate group, suggesting an affective mechanism linking ideology to race categorization. The findings have implications for research on race perception and political psychology.