1. Why do you believe what you believe? What would change your mind?
The problem with polyamory is human nature itself. When you’re in love, even if you’re not the jealous type, you still want to be your partner’s #1 priority. Being told you’re just as important as a second person isn’t very satisfying. And actually, it’s worse than that, because while many poly relationships claim to be egalitarian, in practice there’s almost always a hierarchy, and no one wants to be second fiddle. This tends cause a lot of tension in poly relationships, tension which usually boils over sooner or later.
A second issue (which is often a product of the first) is that poly relationships tend to be unstable. I’m not saying that no poly relationships last long-term but in my experience it’s very, very rare. This is probably the thing that could most easily change my mind about poly—if someone could show that long-term relationships are the norm for poly rather than the exception. But they seem to be like 1% of poly relationships.
2. A polyamorous person hates their partner’s other partner (their metamour). What typically happens next?
I’m not sure this situation ever ends well, but there are probably a few different ways it can play out. Often what happens is the person in the middle will downplay the issues, until one day the metamour notices the other partner being hostile for seemingly no reason, at which it all comes out and one or more people end up feeling manipulated and hurt.
But it doesn’t always take that much time for a situation like that to blow up. Sometimes, somebody gets dumped right away, and not necessarily the metamour. In poly sometimes people get dumped even for diplomatically bringing up an issue they have with their partner’s other partner.
3. What would happen if 90% of people in a society were polyamorous? (You may assume they all practice one style of polyamory, or different styles.)
I have a little trouble imaging what that would be like. I’d think that if polyamory started becoming ridiculously popular, all the resulting drama would start scaring people away before you got to 90% of the population being polyamorous. But if somehow it did happen, I think the results would be really weird. Forget about the divorce rate—would people still have time for hobbies other than poly drama? I don’t know. Like I said I find the whole thing hard to imagine.