Are like what? Is there supposed to be a link?

I was wishing for a "I don't know" button. I haven't really known a large enough cross section of the population to make an educated determination. I am not this way, although I often wish I were because it would save me from eventual heartache. It is a very clinical, cerebral approach to relationships, and for me I'm looking for that subtle, instinctual connection with someone. I'm fairly certain in healthy & happy relationship, both people wish they could give more, and in one doomed to eventually fail, both feel they are the ones giving more and not getting the same from their partner.

Sort of. It doesn't give a complete picture because it ignores the tendency of people to overcommit and, thereby, shortcircuit/bypass the calculation process. People tend to overcommit for family, but will also do it for friends and even complete strangers - else you'd never have people willing to risk their lives jumping into a river to save a stranger from drowning

Its natural

Yes and no. For romantic partners, that's so, at least in the beginning before too much investment has occurred.
With family and relatives, not so much.