Is entering into a verbally agreed upon "contract" of sorts natural in the first place?
Let's not jump to opposites. I wanted to make the point that we have signs pointing to the fact that we are not polygamous - that doesn't mean we're strictly monogamous. Verbally agreed contracts, no. Implied contracts? Yes. A contract here would mean some sort of trust that we help each other out, and we've always been a very codependent species. We hunt together, we live together - all these things can be portrayed as sort of contracts.
Part of what I've been trying to get at is pointing out that most of what we do isn't really "natural" in the sense that our actions are largely influenced by society, and not instincts. It becomes very difficult to identify what is and isn't natural; I guess a better way to look at it is "what are our natural instincts, and how do they influence our decisions, and how do they potentially conflict with societies defined 'norms' or what is 'right' vs. 'wrong."
How queer, then, that Zen Buddhism relies upon finding our "spontaneous nature", yet is a rather monogamous (and not really an abstaining) and not promiscuous culture. But still, we're closing in on something, here.
I don't think anyone in this thread has tried to justify cheating. They've attempted to explain it, and there's a side-discussion of sorts on how we should or shouldn't define relationships due to these definitions potentially conflicting with our natural urges in a way that doesn't make sense.
The "it's natural" has meaning without it having to be a "justification" for cheating. If people cheat often because they are attempting to fulfill a natural desire, then that could call into question the promise of monogamy in the first place.
Then do so, for crying out loud. If relationships doesn't suit you "because of your natural urges", then don't be with someone. More than enough people live in relationships and never cheat, so obviously it isn't a completely fucked up concept.
But lots of humans have also demonstrated the ability to not be hurt by polygamy.
You know, if anything, I'd say this is a hugely cultural thing, not a "natural" thing. I live in Norway, and through all the situations I've been in, all the people I've heard of, only once have I heard that someone are in an open relationship here. This doesn't point to cultures where polygamy is more common as being one that's "closer to the natural state" - it's merely a culture where people interpret their urges or drives in a different way from another culture. This is why Zen Buddhism is the way it is, because they interpret their drives differently. We should all identify with our drives, because our drives are us. The fact that I'm hungry is me, the fact that I'm lusty is me. But I'd venture a guess and say that our culture is influencing the way we think about our drives. No one ever would argue that it isn't exciting meeting someone new, but I feel our culture has taken it a bit far. Focusing so much on the hunt, combined with entitlement and "be free", as if being free is never thinking about anyone else but yourself.
There are many ways to step wrong here. I'm not faithful to my girlfriend because I don't find other girls attractive, I just don't sit around thinking about other girls. If you do, you'll find yourself driven to hump a new girl.
Like many things in today's society, I think this comes from a rotting reflection. Cheating is the relationship equivalent of being fat. It's a short-sighted indulgence in something no one would argue isn't good. Eating candy rocks. But that doesn't make it OK to be fat. You're ruining your body because you can't restrict yourself and have your drives be countered by the drive not to ruin your body. If you can't restrict yourself from humping other girls, it could be considered an unreflectiveness, because we don't see that it's not really worth it, just like stuffing our faces.
edit: as for the "hurting because we get cheated on" it has NOTHING to do with reproduction or sexual behavior, but all to do with self-esteem. If we get cheated on, we think we may not be good enough. If we were lied to, we'll look like fools and that makes us feel bad. If somebody else steals something that is ours, we'll feel like we didn't do enough to protect it. The feelings after being cheated on are not mechanisms of monogamy.
The feelings of being cheated on are a mechanism of evolution. I really don't get the first part of what you're saying. It's like you're mixing up causality. What I'm saying is that we feel all the horrible things we do, because it's beneficial. Pain is nature's way of keeping us from doing something that should happen to us, like pain from sleeping on one side for too long.
I've cheated on my wife, why? I guess it was exciting, knowing someone new and hot, you know that part of a relationship when everything is exciting and new? The first kiss, the first time you see her/him naked, the first time you touch her, shit is amazing. I love my wife, but i also love that feeling, i have to say it wasn't really worth it tho, sex with a stranger is kinda awkward, not half as good as it is with my wife, the woman i've been with for almost 16 years now. I have to say i enjoyed the hunt more than the actual prey, like many have said it's a matter of ego yes, after years with the same person you take a lot of shit for granted, at least i learned to aprecciate my wife a lot more afterwards.
I've thought about what i'd do if she cheated on me, i know i'd feel like shit but as long as she loves me i could live with that, my wife knows about what i did btw.
I don't judge people whodo it cause it's not black and white like many have already said, so much goes on in a relationship everyday, especially long ones.
So. You're pretty much allowing short-sightedness? You're not judging people because you feel it's only human to make short-sighted mistakes? Just because we CAN make mistakes doesn't make it ok. It means that a relationship shouldn't be over by default if someone's cheated, but it sure as hell is a horrible thing to do, still.
So it's black and white. Simple as that. Just because people can have different reasons to kill someone, doesn't mean it's ok.