At the moment, I'm trying to read more about the variants, how they work, so I don't really feel qualified to explain why a person is a certain variant beyond the basics. They're much less defined than the types themselves, which I find a little sad.
All I can say is I'm under the impression that all soc-last people have an innate insular quality to them. They're the ones seperated in the middle of the crowd. But it's definitely not the same as "being different;" I don't think that really occurs as an overt emotion. It's more like a disconnection from the people around them.