The most consistent finding out of this vast literature, the one fundamental result, is that personal space expands with anxiety. If you score high on stress, or if the experimenter stresses you ahead of time—maybe you take a test and are told that you failed it—your personal space grows with respect to other people. If you’re put at ease, or the experimenter flatters you ahead of time, your personal space shrinks. In at least some studies, women have an especially large personal space when approached by men. People in positions of social status or authority have a reduced personal space, especially toward each other. A large, self-confident man who has just been flattered by admirers—President Trump, let’s say—tends to have the smallest personal buffer zone of all.
In the 1990s, neuroscientists made a major breakthrough in understanding personal space with the discovery of a network of neurons in the brain that keeps track of nearby objects. Sometimes called peripersonal neurons, these individual brain cells fire off bursts of activity when objects loom near the body. In my own experiments, I came to call them bubble-wrap neurons. They monitor invisible bubbles of space, especially around the head and torso, and when they rev up, they trigger defensive and withdrawal reflexes.
In the past 10 years, these networks in the human cerebral cortex have been linked to social behavior. They coordinate the unconscious, hidden dance of personal space, computing a margin of safety and nuancing our movements and reactions to others. The mechanism works so smoothly that we don’t usually notice it. Just like ants instinctively feel each other with their antennae to communicate and maintain the larger social order, so we rub personal buffer zones and exchange information at a deep, unconscious level.
To someone like myself, a nerd who has spent decades studying personal space, I can’t help noticing a recent, radical change. As social life migrates online, the old social scaffold of physical space around a human body becomes less relevant. Twitter, Facebook, and texting are lifted out of the face-to-face, spatial framework. Instead, we interact as formless entities, bundles of information in a domain with no Euclidean distance metric. Not all online interactions lose their spatial scaffold—immersive video games maintain a sense of space and distance—but many people now spend an appreciable part of the day in a cyberspace with no real, face-to-face interactions. The human social dance is being restructured at a fundamental level.
At first, I thought this development must be a disaster. Our social skills evolved over millions of years to piggyback off of personal space, and removing that scaffold could muck up our social development. We could lose the ability to connect at a deeper, instinctive level. The cyber-troll phenomenon, for example, is arguably social behavior deranged and disinhibited by the removal of face-to-face, three-dimensional space. And the internet has certainly enabled a vast, dark world of cyberbullying, public shaming, cyber-stalking, and crime.