Is it all about the hunt?

Are we more animalistic by nature then logical?
I've been thinking about this a lot lately especially when talking about sex, sexuality, and human interactions. For instance, have you ever watched the Animal Planet channel when there showing the mating rituals of Lions and your watching and thinking, "Hey!! That was me last night!"... except that everyone either gives you props or starts laughing but meanwhile your thinking, "No seriously that was me last night!"
It's amazing how much we really do resemble our animal siblings. Lately I have been paying more attention to this and noticing how we interact with each other in games of dominance, manipulation, and affection.
In relationships(and this is true with all kinds of relationships)there is always a more dominant person then the other, there is always a more affectionate partner, a more verbally satisfying person then the other and if the roles of dominance were to shift, then so would the "affection giver's" position shift accordingly. But why?
Have you ever noticed yourself chasing after one person but the minute that person proclaims there love for you, you then begin to not feel the same? Why is that? Why do we feel more attracted to what we know is not as easily attainable?
Is human interaction and sexual human interaction all about the chase or the hunt?