I'm very proud of the geek community. As the gay community did with the word queer, geeks wrested control of a disparaging term from the disparagers and took it as their own. What was once derisive is now a source of pride. That is all well and good; I think it's important to remember what a geek once was, however, if at least only to preserve the really unique and weird original sense of the word alongside the new one.
I mean, geeks bit the heads off of live chickens. The original use of geek referred to a type of circus or carnival performer, perhaps one of the lowlier strata of carnies as their talent wasn't so much a talent as a willingness to perform a ghastly act. There was no trapeze or clown car, there was no practice even. It was pretty straightforward: Just bite the head off this chicken and let people watch you do it.
The origin of the word geek is likely derived from the German geck, a 16th century word that described a fool or a simpleton (I like the word simpleton a lot too). Apparently it was first used to describe the carnival goers who thought that maybe they had a pretty good chance at knocking down the milk bottles to win that wood frame Def Leppard mirror. It wasn't until the 20th century that the geek emerged in its true carnie-related sense. According to the Online Etymology Dictionary, geek first came into use to describe any sideshow star around 1916. Thirty years later, it showed up in print in the book Nightmare Alley, by William Lindsey Gresham in the stricter sense of a sideshow performer who plays the "wildman" role. Then, finally, at long last, in the 1970 book, Carnival, by Arthur H. Lewis, this appears:
So by the 70s, geek was slang for a weirdo who bit the heads off of live animals, usually chickens, just in time for Ozzy to adopt it during live performances with Black Sabbath. It wasn't until the 80s and the dawn of the computer age that it became adhered to people who were long on computer skills but short on social skills. Within a decade the conversion from disparaging term to one of pride took place. As World Wide Words describes it:
So there you have it. Today's geeks are related to carnies who ate the heads off of chickens. But geeks are made, not born and how one becomes a geek is a good end to this story, I think. I can't remember who told me this, but it goes something like this: A circus or carnival owner often came across people addicted to heroin or some other drug and would arrange to pay the person in their drug of choice to perform an act that looked like they bit the head off a chicken. Rather than actually bite off the head, the geek was given a razor blade and taught how to cut the chicken's neck surreptitiously to create instead the illusion that he'd just bitten the head off. Now, with the circus owner fully established as the supplier of the geek's drugs, the razor blade would be withheld, leaving the geek only one option to get his fix.