I should establish some definitions, i.e. the social taxonomy that harbors geeks. To start with, it would be incorrect to class all people as geeks merely because they share certain interests or occupations. For example it is possible to be proficient in a technical field, such as computer programming, without being a geek. The tip-off of the geek is not the proficiency, but the mental imbalance that the proficiency feeds from. In a world without computers, the geek would not rise within another vocation, he would instead settle to the bottom of the sediment as a file clerk or other drone whose primary skill is the ability to tolerate mind-numbingly unvarying activity. His proficiency is like that of the idiot savant or autistic genius, albeit less impressive.
The mental imbalance is most readily seen in the geek's masturbatory obsessions. Having no sense of perspective and lacking a personality, the geek attempts to kill two stones with one bird and form a personality around fanatical involvement in an arbitrary pastime. This pastime could involve watching Japanese cartoons, reading fantasy novels, playing video games, or literally just masturbating a lot. The pastime itself is not so significant and has only two universal attributes: that it not require physical prowess, and that it be impossible to distinguish between enjoying the pastime and not enjoying it.
For example, when the geek talks about his pastime he will almost never be able to list the things about it that he likes or dislikes. What he will do instead is describe the pastime's details. The things he claims to like are not the product of subjective awareness but simply the observable characteristics of the pastime.
But there is one crucial difference even here between a thoughtless person and a geek. The thoughtless person will still be capable of discrimination, the geek utterly and hopelessly incapable. The football spectator from my example will enjoy watching particular teams play, and perhaps follow the league to a lesser degree. The geek would follow the entire league, the farm teams, stadium football, college football, fantasy football, and leagues and teams he makes up in loose leaf notebooks. He would subscribe to several football periodicals and have a library of videotaped games. Except of course the geek would not do this with football, he would do this with the literary oeuvre of J.R.R. Tolkien.
Take literature. It is possible to enjoy a work of genre fiction, but the hallmark of the geek is to enjoy only works of genre fiction. Especially when the genre involves elves and muscular lizardmen with laser guns. One could probably go on at length about what makes fantasy and science fiction inferior genres, but to save time their main weakness is that they require no knowledge of any real subject in order to pull off. No homework, in other words, that would involve broadening the reader's horizon or depicting something the reader could not readily make up on his own. Although fantasy novels often take place in a medieval-like setting, it is a completely contrived, ignorant, preposterous medieval-like setting, with no historical analog and very little internal consistency.
Where the geek becomes truly disturbing is in matters of visual aesthetics. His personal appearance, of course, is often weird, repellent, unnerving. When allowed to dress himself the results betray a lack of understanding of his own appearance. Is he fat, bald, dough-faced? You can bet that these qualities will be horrifically exaggerated by his choices in grooming and apparel.
His preferred decor is that of cheap crap--plastic computer cases in the shape of dragon heads, garish poster illustrations of fantasy settings, mismatched discount furniture, etc. It has the same make-do tackiness that is imposed on teenagers still living at home or people earning the minimum wage. But the geek never gives it up; if he makes a comfortable living, he just buys a nicer place in the suburbs and crams all his cheap crap into it.
Worst of all, the geek, despite cutting such a shabby figure, is very self-impressed. He is the first to denigrate other professions, which he assumes require the same slack application and shallow talents as his own does, and the first to denigrate others within his own profession, especially if they threaten his tenuous social standing within his geek circle.
Some questions remain. How do they mate? Is the geek the product of genetic mutation or inherited defect? Politically, is there any viable solution to the geek? I do not seriously entertain the idea of a geek Holocaust--it's far too early for that expensive and complicated measure. But if geeks were provided with free blow-up dolls in the shape of young Japanese schoolgirls or anthropomorphic squirrels, would they then lose interest in procreation?
Of course this assumes that geek traits come about through a quirk of natural selection. It's just as likely that radioactive meteorite, some form of undetected childhood illness, or the drinking of ditch water by pregnant women have played a role.
Whatever the case, we can all agree that the geek is an unpleasant and unsightly blight on contemporary society.