Surrogate bias: Behavioral and physiological effects of seeing ingroup and outgroup virtual agents touching one's embodied avatar.

Social touch is a primary channel for intergroup communication, yet how touch responses are shaped by group membership and individual differences (intergroup disgust, perceived attractiveness, ideological attitudes, implicit bias, and interpersonal distance preferences) remains poorly understood. Immersive virtual reality (IVR) offers a powerful tool to examine such processes under quasi-ecological yet controlled conditions. We recorded subjective and physiological responses - skin conductance and heart rate, used as autonomic arousal indices of implicit reactivity to socially salient stimuli - from heterosexual Caucasian participants (48 men, Experiment 1; 48 women, Experiment 2) as they observed touches applied to intimate, neutral, and social body areas of their gender-matched embodied avatar, delivered by Caucasian or African, male or female virtual agents. Behavioral results showed that men rated female avatars as more attractive, and attractiveness strongly predicted touch evaluations. Intergroup disgust predicted lower attractiveness of outgroup female avatars and greater interpersonal distance, while right-wing authoritarianism predicted greater touch appropriateness from female than male avatars. Women rated outgroup male avatars as more attractive; attractiveness predicted touch appropriateness, pleasantness, disgust, and erogeneity. Implicit racial bias indirectly reduced outgroup touch pleasantness via its effect on avatar attractiveness. Physiologically, men showed increased skin conductance to outgroup male touches on intimate and social areas, while women exhibited heart rate deceleration to intimate versus neutral touches. Interpersonal distance correlated with touch evaluation, suggesting a preparatory role for proxemics in social touch. Together, these findings demonstrate how IVR and physiological approaches can elucidate individual and social factors shaping intergroup proxemics, with implications for prejudice-reduction interventions.