When it comes to inter-personal interactions, I believe there are three shades of areas – black, white, and gray. The other individual’s personal area is ‘black’; it’s off-limit since he/she owns that space and need to feel safe in that space in order to trust others around him/her.
Your own area is ‘white’. It’s open and available to you, and you don’t want anyone else to overshadow it. This white area gives you a sense of privacy and personal space.
And then there is the ‘gray’ area, which is in-between you and the others that you interact with. In a sense, this area is open to anyone, but we try not to use it unless it is absolutely needed. For instance, you could ask a friend for $100 to borrow. That’s going into that gray area. It’s allowed, you are not invading your friend’s privacy, but in normal circumstances, we refrain from entering into such areas. Every time you step into the gray area, you lose a little bit of your value. Try asking for money to the same friend for too many times!
A good collaboration should have clearly marked white, black, and gray areas, and the collaborators should understand how to avoid stepping on black areas (other people’s personal spaces), and limit their access to the gray areas. This will make everyone comfortable and confident in that collaboration.