I saw Miraca Gross speak on this topic and she suggested that gifted kids will be forced to make a choice at some point between being true to themselves at school and pretending they're someone they're not to fit in...
Finally, have you looked in to introversion/extroversion and so on? Many assumptions about socialization seem to me based on what extroverts think people should be doing.
My oldest chose the route of being true to herself which was a harder row to hoe early on but has turned out quite well for her. My younger dd has clearly chosen the "fitting in" route. She has friends and doesn't appear to stand out the way her sister does, but she is profoundly lonely b/c she has little rapport with her friends. Her best friend, probably, is a child down the street whom she tells me isn't someone she really feels deep connection or understanding with, but who is kind and isn't mean to her. Her other friends at school have occassions of being nasty to her and there is some degree of anomosity toward dd b/c she is in more accelerated classes than they are. The other kids in the accelerated classes aren't the best fit for her in terms of friends, either, unfortunately. A lot of them are quite a bit older and bigger than dd (she's rather short) and don't treat her as a peer.
I have wondering if my girls' different choices have something to do with introversion/extraversion, as you mention. Dd11 is an introvert and doesn't seem to feel such a need to have a large crowd of friends. As a result, she has been willing to stand apart from the crowd. Dd9 is a huge extravert. It has been very, very hard on her to be different in any way and she has had a much harder time embracing anything about herself that makes her less likely to be popular.
My favorite bumper sticker I saw years ago said, "it is better to be hated for who you are than loved for who you are not."
I, too, read all the time as a child (including during meals). For me it was an escape from a world in which I was misunderstood and felt disliked, though.
