Face in collision: emotional looming stimuli modulate interpersonal space across development and gender.

Basic visual functions have evolved to allow for rapid detection of dynamic stimuli in our surrounding environment. In particular, looming stimuli are of relevance because they are expected to enter the individual's interpersonal space representing a potential threat. Different studies showed that emotions can modulate the perception of visual looming stimuli and the borders of interpersonal space, defined as the area around the body that individuals maintain between themselves and others during social interactions. Here, we investigated how emotions modulate the perception and the physiological correlates of interpersonal space and whether such indexes change across age and gender. Children and adults were asked to quickly react to emotional looming stimuli while measuring their skin conductance response (SCR). We found that emotional looming stimuli shrink the borders of interpersonal space of males more than females, and that this pattern does not change with age. In addition, adults reacted faster to angry than happy and neutral faces, which is in line with the notion that threatening stimuli capture attention more quickly than other types of emotional stimuli. However, this was not observed in children, suggesting that experience with negative stimuli, rather than the evolutionary meaning they possess, may influence the boundaries of interpersonal space. Overall, our study suggests that interpersonal space is modulated by emotions, but this appears to be modulated by gender and age: while behavioural responses to emotional looming stimuli refine with age, physiological responses are adult-like as early as 5 years of age.