I'm not sure about this. I have a lot of trouble distinguishing between just smart, super-smart, and smart-and-an-expert-in-their-field. Distinguishing them seems to not occur easily simply based on quick interactions. I can distinguish people in my own field to some extent, but if it isn't my own area, it is much more difficult. Worse, there are serious cognitive biases about intelligence estimations. People are more likely to think of someone as smart if they share interests and also more likely to think of someone as smart if they agree on issues. (Actually I don't have a citation for this one and a quick Google search doesn't turn it up, does someone else maybe have a citation for this?) One could imagine that many people might if meeting a near copy of themselves conclude that the copy was a genius. That said, I'm pretty sure that there are at least a few people out there who reasonably do qualify as super-smart. But to some extent, that's based more on their myriad accomplishments than any personal interaction.