It could happen just about any time you step out in public. You get onto an almost-empty bus, but the next passenger inexplicably decides to bypass dozens of vacant seats to sit right next to you. While you’re waiting in line at the supermarket , the next customer insists on standing only two inches behind you and shouting into his cell phone . You go into a public restroom, and the next person to enter decides to use the adjacent stall. Transgressions like these don’t just make us feel uncomfortable; we often feel squeamish, anxious, alarmed, and downright violated. It’s the attack of the personal-space invaders.
In any society, shared definitions of personal space govern how we interact with other people. We all have an unspoken expectation that we’ll be granted a small “bubble” of sanctuary around our bodies, and when someone pops that bubble by standing or sitting too close or extending an unexpected touch, we feel intruded upon. Our perception of personal space is one of our deepest and most powerful forms of nonverbal communication, and we expect other people to play by the rules. Not only is it upsetting to experience an invasion into our physical space, but we also react to breaches in our psychological space, like intrusive scents, sights, and sounds, such as overpowering perfume, lecherous gazes, or loud music.
Based on our understanding of how personal space works, researchers can accurately predict which stall people will choose when they walk into a bathroom , and which seat they’ll take at a communal table They also know that humans react to personal-space invasions with stunning similarity.
The Study of Space
In 1966, an anthropologist named Edward Hall coined the term proxemics, which he called the study of the distance between people as they interact. Hall found that people’s body language , posture, and need for personal space changed subtly depending on their precise circumstances. He visualized a person’s personal-space requirements as a target, with the person standing at the center, and designated four zones, radiating outward in concentric circles, that marked acceptable distances for interaction:
- Intimate distance, from six to eighteen inches away from the body, is used for interacting in intimate relationships and kissing, hugging , or embracing.
- Personal distance ranges from 1.5 feet to four feet away from the body, and is used for talking with good friends, family members, and those the person knows well.
- Social distance, from four to twelve feet away, marks the space required for interacting with coworkers, acquaintances, or professional service providers, or having other polite but impersonal encounters.
- Public distance is the required space for public speaking , and can range from twelve feet to twenty-five feet away.
Room of One’s Own
Our adherence to personal-space rules is so strong, it’s even been found that people who play virtual-reality games like Second Life  follow real-life personal-space rules within the game. But one big problem with personal space is that every person has a slightly different definition. In general terms, cultural influence is a major determinant of personal-space requirements. People in the United States, Canada, England, and Nordic countries have the largest personal-space requirements. Those living in South America, Europe, and Asia have far smaller standards of personal space.
Even within a country, people’s definitions of personal space vary depending on the population density where they live. People living in densely populated cities like Mumbai, Beijing, or Mexico City  tend to require less personal space than people living in sparsely populated places within the country. In America, New Yorkers often have smaller requirements than residents of western states, like Montana and Wyoming. Because everyone has different standards, gestures that are innocent in one place can be interpreted as hostile in another. Some people might see those with small personal-space requirements as pushy or rude, while those with large personal-space requirements are sometimes seen as cold or aloof.
Sometimes it simply depends on the individual person and his or her mental state, gender, social status, and history. Psychologists have found that women have smaller comfort zones than men. People of higher social stature demand more personal space than those of lower classes. Victims of abuse  usually display a need for larger amounts of personal space than other people, and demands for extensive personal space are common traits of certain psychiatric diseases, like schizophrenia. It may even be possible that damage to certain regions of the brain could result in lessened perception of personal space. A study from the California Institute of Technology, published in the journal Nature Neuroscience, found that people with damage to their amygdala, an organ that processes memory and emotions, had a lessened concept of personal space. Ultimately, most of the personal-space invaders we encounter are simply people who are inept at reading social cues and don’t realize that their behavior is intrusive.
Going to Your Happy Place
Whether people are confronted with a close talker or a bus-seat buddy, experts have identified that most people react with a similar set of evasive behaviors. In public spaces, people reliably try to keep as much distance between each other as possible, and most instinctively try to keep equidistant, like birds on a telephone wire, to permit each person the maximum amount of space. Two people in an elevator will stand in opposite corners; three people in public restrooms will insist on at least a one-stall buffer between each of them. People tend to avoid eye contact in crowded public situations; this helps to avoid intimacy and results in people’s thinking of each other not as human beings, but as inanimate features of the environment—much easier to ignore. Some try to create at least an approximation of physical boundaries by opening up a newspaper or book, which creates a separation between the reader and the rest of the crowd. On a crowded subway car, this gesture is like putting up a miniature wall. It’s even common for people to put bags or purses on their lap in an unconscious move to protect themselves and their space, or to close their eyes completely to create the illusion of psychological space. Some psychologists have even theorized that the popularity of iPods is due at least in part to people’s intense and innate desire to carve out a private zone for themselves.
Maintaining personal-space boundaries is normal. It’s okay to be a little creeped out when a stranger passes up empty chairs to sit next to you. It’s okay to recoil a little when a waiter touches your arm unexpectedly. There will always be people without an understanding of the basic rules of personal space. So just relax, open up a newspaper, and start whistling a few bars of “Don’t Stand So Close to Me.”