You've been there before. You're standing in a public place and a stranger approaches you. They stand right next to you, in your "personal distance" (1 ½ - 4 feet away). You wonder why they're so close, but you stand your ground. Then they decide to start a conversation, and they are wayyyyyy too close. What could be worse? Their breath smells, of course. Ever notice how people that have really bad breath always want to tell you secrets? Why is that?
According to the textbook, there are 4 levels of personal space. Public distance, 12 or more feet, is known for public speaking or a professor in lecture. Social distance, 4 to 12 feet, used for when you meet someone knew (obviously the person in the situation above is unaware of this). Personal distance, 1 ½ to 4 feet away, is reserved for your close friends and significant others. Intimate distance, 1 ½ feet or less, is saved for kissing, hugging, whispering, and affectionate touch.

So why is it that not everyone is aware of these four levels and find the need to make you feel uncomfortable? When you're at a party and a guy/girl decides to make you their "target" for the night. Notice the intimate touching and that they are coming way too close?
I'm just saying... strangers should take notes on these levels of personal space.

I liked that you talked about the "target" thing. That totally happens. On one hand, it can make you uncomforable. On the other hand, it's sometimes welcome :)
I think it's also interesting that personal space can vary by culture. Americans for example, are used to greater personal space during conversations then Italians (http://www.culturecrossing.net/basics_business_student_details.php?Id=9&CID=102).
I feel like everyone is aware of these spaces it is just whether they listen to them or not. And some people have different ideas about their personal space, because there are those who don't mind being close to others and then there are those who do want to be close. I just find it interesting that they put feet markers on how far away most people are comfortable with.
Nice graphic. I remember reading in another class text how birds have this intuitive built-in spacing too. Birds on a wire and birds flying know the appropriate space. I'm also interested in the differences between cultures with personal space and expression, particularly affection.
Before we exactly know this information, we would already feel that what distance between me and a stranger makes me feel uncomfortable or feel better. I think this can be different from each people slightly. In other words, there can be a individual difference in this distance of space. It can be caused by personality or reared environment and even by different culture accross countries.