The researchers discerned the result from an Internet-based experiment with 457 volunteers. Participants were presented with virtual characters on their computers screens, some wearing masks and some not, at various distances away from the subject. Subjects were asked to judge whether the “interpersonal distance between themselves and a virtual character was appropriate for social interaction or not.”

“Each virtual character was presented twice,” the researchers explained. “Responses were provided by pressing the “L” (appropriate) or “S” (inappropriate) keyboard keys. Participants were instructed to respond spontaneously and as fast as possible.”

Tallying the results, the researchers found that subjects permitted a much closer interpersonal distance for virtual characters with face masks compared to those without face masks. Volunteers allowed mask-wearing characters to be about 15% closer.