Unpacking the social nature of interpersonal distance: Behavioral and physiological insights from real-time...

Interpersonal distance (IPD) refers to the space individuals maintain between themselves and others to facilitate comfortable interactions. In a series of three experiments, we collected both behavioral (IPD preferences) and physiological (electrodermal activity) measures from 86 participants performing different versions of the Stop Distance Paradigm. Our aims were to (a) investigate IPD correlates when individuals actively regulate their interpersonal boundaries according to personal comfort, (b) target the physiological components of space invasion, (c) isolate the social components of IPD from other non-social factors and (d) examine the role of higher-level social mechanisms and interpersonal cues provided by the interacting person. We found that when individuals actively regulate their interpersonal boundaries, active and passive approaches modulate IPD differently at both behavioral and physiological levels. When individuals lack control over the interaction, violations of personal space elicit strong autonomic responses, reflecting an affective reaction to boundary intrusion. Notably, these responses were specific to human interactions, underscoring IPD as a social construct rather than a mere function of spatial proximity. Finally, we propose that IPD is modulated by perspective-taking strategies (self- vs. other-focus) and social cues such as gaze direction and other's attitude. Together, these findings offer a more comprehensive view of IPD as a dynamic, bidirectional process characterized by integrated behavioral and physiological signatures.