I have seen so much people talk about it, here in the forum from duality members as well as in real life interaction that both party feels this unusually calming effect, Usually we force ourselves to interact with other 15 types to engaged in conversation, Mask are implemented and we have a set of causal greeting to people, which isn't really our true selves. With dual, there is a realization that you don't need to do that, but you still mask it anyway becuase you don't know that they are your dual, but the vibe you get from your dual you realizing automatically that its better not to forced anything, centered yourself and a "real conversation can begin. I also noticed that in a group atmosphere that duals don't click so well becuase you always adapt a different approach in group talks than in one-on one conversation. I think if you find a dual that has the same enneagram instinct as yours, this would solve the problem.
Do you feel calmer with your dual in Social situation(not one on one)?