Not only that, but there are group marriages with multiple men and women. I think it is a wonderful thing to have more adults take care of children, and have sound finances. The more the merrier in my opinion (as long as everyone gets along.) 

I don't support either.

You seem to make a point here without elaborating.

I'm in love with my two waifus

Instinctively, I'd say I support neither. Thinking about it though, I realized that this instant rejection came mostly because I can't image myself doing it. It feels weird to me, but this doesn't mean that I won't allow and support people who want to live that way.
So yea, I support it.

Given human nature, polyamory works as well as a rain dance. And polygamy is often linked to societal repression of the female sex.

So, nah.

That's where you're wrong.

Yes, because I definately don't 'support it' but what other adults do is non of my business.  So I would check something else.

But I do usually avoid those people - we just see the world differently.  Like if I found a gay couple was in an 'open' relationship, then I kind of avoid them - try to make sure I'm never alone with them, etc.  Not because I think I think they will force themselves me, more because I would rather avoid any awkward moments and we are just fundamentally different people.  And in my experience most gay couples doing that are just prolonging their eventual break up.

Usually in nature, the more helpless the offspring, the more monogmous the animal.  Humans by nature I think are supposed to be together for about 7 years to raise a kid (or longer if they have more kids or choose etc.)  Although some people aren't like that.  Some people just can't be monogomous and other the oppisite.  Then there are a few asexual.

Oh, and I think many of the poligimy practicing cultures today are still very opressive to women.  There are a few one woman multi man situations too and that to me is just their business.

And monogamy works? The divorce rates and the amount of infidelity would say otherwise. And again marriage in general was a way of owning women as property regardless of it being poly or mono.

With polygamy, and a fairly even split of male-female ratio worldwide, if every relationship involved 2 women per man. 1.5 billion men would not have a spouse and would lose the ability to have children of their own. Due you understand the implications this would have on society, or is everyone here simply looking inside the box while saying "as long as it doesn't harm anyone"? How about if as many men as possible had 4 wives... You see where this is going?

It's also been documented that boys born into polygamous cultures are often cast away by powerful elderly men as to limit competition. These boys often become delinquents, join gangs, commit crimes, etc.

Just saying, if I had no woman due to other men hogging more than 1, I'd find the man with the most wives and off him. You'd force a lot of hands with this setup. Terrible idea.