Don't stand so close to me: a behavioral and ERP study of preferred interpersonal distance

The space between people, or interpersonal distance, creates and defines the dynamics of social interactions. Given that invasion of one's interpersonal space may trigger threat and anxiety, a critical question is if high vulnerability to social anxiety (SA) is associated with avoidance and attentional biases when anticipating invasion to one's interpersonal space. Therefore, the current study sought to examine the behavioral mechanisms, time course and neural correlates underlying the threat of interpersonal distance invasion with a focus on different SA levels, using both a behavioral and an ERP experiment. Preferred interpersonal distance was assessed using a paradigm that involves responding to different virtual protagonists (friend or stranger) approaching the participant by indicating where one would like the protagonist to stop. In addition, participants' level of social anxiety was measured. The behavioral experiment indicated that levels of SA predicted one's preferred interpersonal distance such that higher SA individuals preferred further distance from a stranger. At the neural level, across groups, early (N1) but not late (LPP) differences were found between stranger and friend conditions. Importantly, SA individuals were characterized by attenuated early ERP responses, suggesting less attentional resources allocated to social stimuli. The results suggest that high SA individuals feel discomfort earlier than others in social engagement, which may lead them to stand further away, thus creating less communicative social interactions.