Clearly, smarter people have fewer friends. But this is because of several factors. One of them is even the ability they have in analyzing other people and in seeing what they can have of good and bad and what an impact it can have on their own lives. I can say that I consider myself intelligent enough to know what type of people I want far from me and what type of people I want close to me, and clearly that over the years I have been getting less and less because I see a general thought that I don't like very much.
And I could even say many other factors here, but you've already mentioned some very interesting ones.
Good article friend :)
Cheers,
@ t-miles