The Spread of Fear: Perceptual Deindividuation Drives Racial Bias in Fear Generalization

Fear often generalizes beyond its original source, but little is known about how social categories like race shape this process. In a fear-conditioning paradigm, 284 racially diverse participants learned to associate an aversive sound with one Black and one White face. We then assessed how participants generalized fear to novel faces varying in similarity to the original target. Although physiological responses tracked physical similarity regardless of race, behavioral responses revealed a racial asymmetry: participants generalized fear more broadly to novel Black faces. Sigmoid modeling showed that participants applied a lower perceptual threshold when identifying Black faces as threatening. These biases were most pronounced among individuals high in general threat sensitivity, who relied less on similarity when evaluating Black faces, resulting in more frequent misidentification. These findings offer a novel perspective on how fear spreads across group members and contributes to real-world disparities in threat perception and misidentification.