I earned my degree in Psychology. I love the brain and everything about it. My Biological Psychology professor really drove home the fact that everything with regards to the brain, behavior, personality, etc. is on a spectrum. There are no black and whites. 

My first post on this forum tangentially touched on one spectrum I'll call the Geek Knowledge Spectrum: breadth vs. depth of knowledge. This time I want to talk a little about what I'll call, for simplicity sake, the Geek Personality Spectrum. Trust me, I am very well aware that personality is far more complex than the simple measure of introversion/extroversion; however, this metric can be very instrumental in understanding one another.

One of the experiments we performed in my bio. psych. course, mentioned above, was to attempt to replicate an experiment to test a famous introversion hypothesis by Hans Eysenk. His hypothesis said that introverts are introverted because they have more baseline brain activity, as measured by EEG which means they need less external stimulation, in fact, they become over-stimulated quickly because of the higher baseline, that's why they prefer more quiet, solitary activities as opposed to loud, crowded parties, etc. for entertainment. Conversely, extroverts have lower baseline brain activity, so therefore need more external stimulation. Eysenk's results supported his hypothesis, and it is fun to think that he's right because it "makes sense", however, many others have attempted to replicate his study with mixed results; some supporting his hypothesis and some refuting it.

I am most clearly an introvert; most of the time a prefer quietly reading a book as opposed to hanging out at loud parties. I also have a small number of close friends, instead of many friends/groupies/entourage/what-have-you. Looking at "geeky" activities, I would hypothesize that self-described geeks would fall closer to the introverted end of the spectrum. That's not to say ALL geeks are introverts, and especially not that all introverts are geeks. But I would be interested to see where a large sample of self-described geeks (i.e. this community) feel they fall on the spectrum and if they think there is my validity to my hypothesis.

As an aside, a while back I found this blog post and thought it was a really good resource for everybody to understand introverts better. If you are one, read it to understand yourself. If you're an extrovert, read it to understand us. The post also explains Eysenk's hypothesis better than I did and points out that only about 25% of the total population are introverts, so I think it would be interesting if Geekdom had a higher proportion.