It seems to me there are a number of ways to view a human relationship. As it happens, I tend to look at relationships from a quite mechanistic point of view. This perspective has a tendency to get me in trouble. It is generally more socially acceptable to derive value from emotional attachment in direct proportion to the intimate nature of the relationship. It is perfectly acceptable, or even preferable, to have a “Professional” relationship with colleges and clients. This sort of relationship is also fine with acquaintances and occasional friends. But as these relationships become more personal the expectation is that a properly socialized person will become more emotionally invested in these relationships.
In every case all relationships are furthered on a quid pro quo basis. Stating this simple fact will also get you in trouble. People don’t like to admit to the mechanics of their nature. Everyone takes action to move themselves into a position of perceived greater comfort; Even when what they desire would seem like it would make them more uncomfortable. People tend to enter relationships that offer greater value. And work to assure this value when the relationship is fully or semi- exclusive.