JacobGrimm: I think you reflect the considerations of many Laura. Where does this consideration come from though? The origins of our human behaviors are plottable. It is how we become who we are, by 'observation' (any form of learning) of repetitive behavior from others.
I think these "considerations" came from my basic needs, not from 'observation' of repetitive behavior from others.
In general, I like to think of it as a partnership
Dusty45: Marriage is a partnership which may or may not include Love.
just like

Dusty said
JacobGrimm: I guess the question is, would we be healthier as a species had we chosen other 'behaviors'
My sense of this comes from what you say as well
This is essentially, "being in the now", indulging the moment of posssession for lack of a better word. Its undeniable that we all do this, though for some the moment is longer or shorter than others. (relationships just don't last in general, nor are they all encompassing)
Are we keeping the "marriage forever" notion, to avoid the heartache of loneliness, that part that involves searching, that part that involves being alone. Do we set ourselves up for disappointment in the surmissed granduer of marriage forever.
Would we be more healthy (one has to think about this without the preconcived notions of moral code)if we just took each moment as it comes, without emprisoning ourselves in monogamy... and still maintianing the use of respect for others as well
I understand what you are saying, but I don’t believe it's learned 'behavior', hence I don't think we would be healthier as species "had we chosen other 'behaviors'".
Take for example any other partnership:
a commitment to emotional and psychological support between two people would define it for me.
Add lust to it and I wouldn’t go farther searching for this elusive love... that everyone has their own definition for. This combination would do just fine for me,
I think. It's a good basis for love to grow, when 'in-love' wears off. And it's not imposed by anything but my primal needs. So does monogamy (to me).
No, they, in general, do not. Because people

don't get what they need out of it. Back to emotional and psychological support, and physical needs to be met.
I, by the way, don't think that many people can give what it takes for a relationship to last. And not just because they don't want to, but simply because they are not capable of it, they are not evolved enough.
That's where hate and intolerance to another gender comes from: mismatch between feeling entitled and not capable of 'giving', not being developed enough ... never mind

- it's already a different topic
Gosh, no - nothing would make me feel lonelier than staying in a 'disfunctional' relationship. By the way women keep repeating it again and again in forums: better alone than with a wrong person.