nancylebov for the link to this excellent piece on five social fallacies of geeks.http://www.plausiblydeniable.com/opinion/gsf.html
I would note there is also the "My group is superior to the population as a whole," which can prompt geeks to disparage mainstream hobbies and social interactions and disregard the opinions of people not in the subgroup. But this fallacy is not limited to geeks.