Our Invisible Bubble
It turns out there are at least three recognised gradations of personal space which ripple out from us.
The next circle around us is 'expected contact' or 'personal space'. This unwritten zone boundary extends from 1.5 feet to 4 feet away from us and we're certainly more comfortable with friends in this close proximity than strangers although it's the area used to shake hands with a new acquaintance. This zone is for the rest of the family and friends and the closer we accept them the more intimate the relationship.
But we can cope surprisingly well with expected personal space intrusions, such as busy commuting conditions, by temporarily dehumanising ourselves and avoiding eye contact. Anyone who has travelled on the London Underground at 8am will know this well. We can use these coping mechanisms to deal with short-lived situations yet it becomes more stressful if prolonged.
Outside of that is our 'social space' or 'social distance' which is 4 to 12 feet away from us. This is acceptable for routine social interactions and new acquaintances or for people you know but not well such as the postman or delivery drivers.
The rest is considered 'public space' or 'public distance' and we have no claims on that so it's for everyone else. Public speakers use this space to address an audience and know that the other people in the room will not have raised anxiety levels, unless the talk's topic is meant to do that.
While we are not born with knowledge of personal space, psychologists say children gain it as they become more self-aware around three or four years old. Cultural differences and upbringing also play a large part. A family that likes to hug can cope better with strangers within their personal space zones than a more reserved family. Someone with less personal space awareness may stand too close to you increasing your anxiety without them realising the effect. We've all had that feeling in a new and different country where strangers are just too close for comfort.
This unwritten rule of personal space can be seen when strangers choose a seat in a row whether on a train, at an open-air theatre or in a classroom, we all want to sit on the end. Without consciously realising it we are choosing a way to only have our personal space invaded on one side. Yet those seats at the end of the rows must be the dirtiest of all as they are used so much more. If the end seats are taken already we'll leave a gap and not sit next to a stranger to keep that invisible bubble safe.
It turns out this happens in public toilets too as the cubicles on the end of a row get used more often.
My tip to you is to sit one seat in from the end of row – it's got to be cleaner as it's left empty so often – and use the middle toilet.