In the movies, more people are probably murdered in elevators than in any other closed space—perhaps with the exception of the shower. In reality, the probability of being the victim of a deadly attack in an elevator is virtually zero. Yet the way people act toward others when they ride together in an elevator suggests that they have serious concerns about their safety. If the elevator is crowded, everybody stands still and stares at the ceiling, the floor, their watch, or the button panel as if they've never seen any of these items before. When two strangers ride together, they stand as far apart as possible, and avoid facing each other directly, making eye contact, or making any sudden movements or noises.
Much of our elevator behavior is not the result of rational thinking. It's an automatic, instinctive response to the situation. The threat of aggression is not real, yet our minds respond as if it were and produce behaviors that are meant to protect us. Elevators are relatively recent inventions, but the social challenges they pose are nothing new. The scenario of being in close proximity to others in a restricted space has been repeated innumerable times in the history of humankind.
Imagine two Paleolithic cavemen who follow the tracks of a large bear into the same small, dark cave. There each discovers, not a bear, but another hungry caveman ominously waving his club: clearly an awkward situation that requires an exit strategy. In those Paleolithic days, murder was an acceptable way to get out of socially awkward situations the way we use an early morning doctor's appointment as an excuse to leave a dinner party early. In the cave, one of the cavemen whacks the other over the head with his club and the party is over. Occasionally, the caveman's chance encounter is with a female of the species, which makes it an opportunity for reproduction. But if a male caveman encounters another of his kind, it's bad news. Similarly, when male chimpanzees in Uganda encounter a male from another group, they slash his throat and rip his testicles off—just in case he survives and has any future ambitions for reproduction.
Our minds evolved from the minds of these cavemen, and their minds, in turn, evolved from those of their primate ancestors—apes that looked a lot like chimpanzees. Although some of our mental abilities appeared relatively recently in our evolutionary history, the way our minds respond to potentially dangerous social situations is nothing new. Just as the way we feel pain in response to bodily injuries probably hasn't changed in millions of years, the way primate minds respond to social threats hasn't been modified very much either. On the contrary, evolution has been so conservative in this domain that the minds of humans, chimpanzees, and even macaque monkeys—whose ancestors began diverging from ours 25 million years ago—still show traces of the original blueprint.
The way people behave in elevators is not a popular topic for scientific research these days, but it was all the rage in the 1960s. An anthropologist named Edward T. Hall wrote a book in 1966 called The Hidden Dimension, in which he argued that when a person invades someone else's personal space, all kinds of trouble ensue. According to Hall, personal space is like an invisible bubble that people always carry around themselves. The radius of the bubble can be short or long, depending on the individual or the cultural norms of the society in which he or she lives. Noting that human personal space is the equivalent of an animal's territory, Hall suggested that aggressive responses to violations of personal space represent attempts to defend one's territory.
Given what we now know about animal behavior, the analogy between human personal space and an animal's territory is no longer useful. Territorial behavior is quite rare in primates and mostly confined to species that are only distantly related to humans. Moreover, humans do not aggressively defend the invisible bubble around themselves the way territorial animals defend the place where they live. What we do instead is take measures to protect ourselves from the risk of aggression whenever potentially dangerous individuals are close to us. Being next to another individual simply increases the probability of aggression, especially if this individual is a stranger. The relationship between close proximity and risk of aggression has been studied and is well understood in other primates, including species that do not defend territories, such as rhesus macaques and baboons. By recognizing the evolutionary continuity between the human mind and the minds of nonhuman primates, it becomes clear that people's reaction to the presence of others in an elevator is simply a response to the risk of aggression.
When two rhesus macaques are trapped together in a small cage, they try everything they can to avoid fighting: moving with caution, acting indifferent, and suppressing all the behaviors that could trigger aggression are good short-term solutions to the problem. The monkeys sit in a corner and avoid any random movements that might inadvertently cause a collision, because even a brief touch could be interpreted as the beginning of hostile action. Mutual eye contact must also be avoided because, in monkey language, staring is a threat. The monkeys look up in the air, or at the ground, or stare at some imaginary point outside the cage. But as time passes, sitting still and feigning indifference are no longer sufficient to keep the situation under control. Tension between the prisoners builds, and sooner or later one of them will lose her temper. To avoid immediate aggression, and also to reduce stress, an act of communication is needed to break the ice and make it clear to the other monkey that no harm is intended (or expected). Macaque monkeys bare their teeth to communicate fear and friendly intentions. If this "bared-teeth display"— the evolutionary precursor of the human smile—is well received, it can be a prelude to grooming. One monkey brushes and cleans the other's fur, gently massaging the skin and picking and eating parasites. This act can both relax and appease another monkey, virtually eliminating the chance of an attack. So, if you are a rhesus macaque and find yourself trapped in a small cage with another macaque, you know what to do: bare your teeth and start grooming. If you are a human and find yourself riding in an elevator with a stranger, I recommend you do the same: smile and make polite conversation.
One morning when I was living on the 20th floor of a high-rise building I rode the elevator with a middle-aged man who seemed to be particularly intimidated by my presence. As I stepped in, he smiled nervously and started talking immediately. He talked non-stop and managed to give me his entire medical history, complete with symptoms, diagnoses, and treatments, before we reached the ground floor. I doubt that this man expected to receive medical advice from me. Rather, he was clearly an insecure and emotionally vulnerable person who used massive verbal grooming to appease a perceived potential aggressor in a risky situation. Not all my experiences are like this, of course. When I ride in an elevator with an attractive woman, I'm generally treated with indifference, which in this case is not a sign of fear or intimidation. When my girlfriend rides in an elevator with a man, the man often strikes up a conversation with her and ends up asking for her phone number. People's responses to potential mating opportunities are just as predictable as their responses to potentially dangerous situations.
The beauty of human nature, however, is that although the average behavior of human beings can be scientifically predicted, there is a lot of unpredictable variation above and below the mean. Once, on the way up to my apartment, I met an old lady who got in the elevator on the 2nd floor, pressed all the buttons from the 3rd through the 22nd floor, and walked out on the 3rd floor with a grin on her face. For more, see: Games Primates Play, or follow me on Twitter