"One thing that seems to unite the polyamorous community is a real enthusiasm for digging into emotions. Honesty, openness and communication are cornerstones for polyamorous relationships, Holmes has found.
"They're talking a lot, they're negotiating a lot, they're bringing their feelings to the table a lot," he said. It's this intensive conversation that might be wise for monogamous couples to emulate, Holmes said. His work also suggests that basic emotions work very differently in polyamorous relationships.
Take jealousy. If you ask most people how they'd feel if their partner had sex with or fell
in love with someone else, the responses would be pretty negative: fear, anger, jealousy, rejection. Ask a polyamorous person the same question, and they're more likely to tell you they'd be thrilled. It's a concept called "compersion," which means the joy felt when a partner discovers love outside of you. It's similar to the feeling the typical person might get after finding out their best friend scored her dream job, Holmes said. But in this case, the happiness stems from a lover's external relationships.
That finding challenges much of what traditional psychological research has established about how jealousy works."
Read more:
https://www.scientificamerican.com/article/new-sexual-revolution-polyamory/