In human civilisation there has always been a sense of self. Sometimes called id or ego, each person is an entity in his or her own right. In western cultures there is emphasis on the needs of the individual¹, while other world cultures may concentrate on communal 'hive' existence² so a sense of self is not as important. The concept of personal space³ is an invisible and undefined three-dimensional area surrounding an individual which, when invaded, causes sensations of nervousness, discomfort and/or embarrassment. It is a common human psychological phenomenon.

The Invisible Comfort Zone

Have you ever had the feeling that someone has got a bit too close to you for comfort? Halitosis (bad breath) aside, your mind is telling you that the other person has crossed an imaginary line. Chances are that they have invaded your personal space. So what is personal space? And why do we feel so strongly about it? Some may say it is 'an area with invisible boundaries, surrounding a person's body into which intruders may not come.' It is often referred to as being like a bubble that we carry around with us, which can expand and contract according to the situation. Others quite simply remark it's their personal space buddy so get the heck out of it now or they'll call the cops. Whatever the case it is something that humans use when interacting with each other in everyday life.

There is some speculation that the human need for personal space stems from evolutionary sources. The theory goes that the introduction of unknown and potentially dangerous objects or entities into the space immediately surrounding a soft, shell-less human triggers a desire to run away, and perhaps further explains the amusing habit of many humans to squeak like a small rodent when suddenly tapped on the shoulder.

Personal space may also stem from the animalistic behaviour known as 'staking territory'. Most animals will claim territory using scent glands or urinating, as demonstrated by dogs upon trees, lampposts, fire hydrants or mailmen. Humans however, due to social constraints, have a more difficult time of it. With little or no concept of territoriality or territorial behaviour, humans may tend to move randomly from one place or another with no place to call home.

Imagine, if you would: strangers wandering into your own home without knocking, then eating your food, using your toothbrush and sleeping in your bed, before walking out and taking some of your things with them⁴. This is invasion of territory, and thus it is important for us to define that territory - personal space.

Su Casa, Mi Casa (Your House is my House)

The exact dimension of an individual's personal space may also be partially culturally determined. Most notably, those that flourish in extremely populous areas seem to result in far smaller personal space requirements than others. It is unfortunate to note that, in most cases, those cultures that encourage the smallest amount of personal space also encourage the loudest volume of personal speech, whereas those from vast, sparsely populated, areas of the world seem to be in direct dichotomy.

There are many aspects involved in the determination of personal space and it can be affected by a variety of social factors including cultural backgrounds (monochronic or polychronic), social class, sexual orientation and disabilities. For instance, the personal space of married individuals is smaller when approached by the spouse than when it is approached by some other individual. Personal space tends to be greater when a person is approached by a stranger who is perceived as creepy than when they are approached by someone who appears normal. It is interesting to note, however, that the personal space of most humans does not extend upward. Disgusting insects and rude hand gestures may therefore be safely dangled immediately above an individual's head.

Most important in achieving your own imaginary protective bubble, however, is to assess how you are communicating and interacting with your fellow human beings.

'You Talkin' Ta Me?'

Although, for the most part, the idea of personal space is more implied than spoken in daily life (even more so among adults than children), here are some suggestions for determining the dimensions of someone else's personal space:

• Stand approximately three metres from the person you are attempting to talk to and begin a conversation. When they come closer in order to actually hear you they will probably stop at the edge of their own personal space.

• When speaking, some people find it necessary to touch another human, or wave their arms and hands about wildly in order to enunciate. When confronted with this situation, wait for the other person to touch you. That way you can either acknowledge their own personal space, or confront them with yours. If you touch first you may initiate either a) passion or b) anger. Neither may be appropriate in the context of the conversation.

• While sitting at a table or sharing a meal, move a small object, such as the salt cellar, closer and closer to the other person. When they frown and move it away again, you have probably entered their personal space. Of course, this could also mean they want you to stop playing with the condiments and pay attention to the conversation - so this approach should be used in moderation.

Similarly, if someone enters your personal space without permission, here are some suggestions for regaining your immediate comfort zone:

• Do not step back. In the majority of human cultures this is considered a sign of weakness or discomfort and will probably send the wrong message. Attempt to move laterally so as to increase the distance between you without being obvious. Alternatively, move the interaction to another venue (such as a nearby seating area) where you will be able to place more room between you.

• Inform them that they are standing too close and ask them to move back. This should be done with caution as it may imply a distaste for their presence or excessive fastidiousness on your part.

• Excuse yourself briefly on some pretext and re-establish the correct amount of space when you return.

'No Man is an Island'

Unfortunately for the sanctity of personal space, the planet earth is a crowded place and does not always allow an individual the amount of space they may desire. It is often necessary to accept invasions of personal space or to perpetrate them on others in order to survive daily life. Certain instances that directly throw the book out of the proverbial window are:

• Passion (see also sex)
• Healthcare industry (nurses, doctors etc)
• Large gatherings (rock concerts, sporting events, graduation ceremonies, riots)
• Queuing
• Travelling on public transport (see also the tube)
• Criminal activity⁵

Note: In all human cultures currently active, violent and/or homicidal responses to the invasion of personal space are severely frowned upon. This does not, however, significantly decrease the desire towards such actions on the part of many humans. Approach with caution.