Researchers recently evaluated personal spacing comfort with people we know; much of the previous research had evaluated distances we keep from strangers. Mukai, Isomura, and Onagawa (study published in Scientific Reports) “investigated the responses to the presence of friends and acquaintances at different relative positions in IPS [interpersonal space, at a distance of 30 cm]. . . . the greatest discomfort, the greatest decrease in heart rate, and the greatest increase in HRV occurred in the F-see condition [participants stood face-to-face with their friend and looked at the center of their eyes]. The researchers attributed the decrease in heart rate and increase in parasympathetic activity to the presence of familiar people. . . heart rate only decreased in relative positions F-see and R-see [the participant looked at their friend’s right profile with their eyes fixed on the head]. . . . ‘Our study suggests that social relationships between two people influence our physiological responses during social interactions,’ says Dr. Mukai.”
“Exploring the Effect of the Presence of Familiar People in Interpersonal Space.” 2024. Press release, Waseda University, https://www.waseda.jp/top/en/news/80258