Being a social introvert, I've always been painfully aware of the 'bubble', that divide between persons to be adhered to at all times beyond extraordinary circumstances or bonds shared.
When it comes to family and close friends, I don't mind closer than normal contact. My niece and nephews/cousins can sit on my lap or lean against me on the couch, aforementioned friends may sit adjacent, and physical touching can be allowed... provided I'm aware of the intention ('I'm going to hug you, touch your...') to do so. My neck area is crossing into haphephobia.
When dealing with strangers, if it can be managed, I will always put at least three feet of distance between us, and I despise going into crowded areas for this reason. I shirk away from long lines, elevators, etc. If my attention is elsewhere and I find someone has decided to stand rather close to me (such as examining the same book or video game shelf) I will go elsewhere until that person moves on and I'll return.
