I think about this a lot since I tend to believe that American culture tends to favor extroversion, and I also believe that a big reason I was laid off is because I was an introvert in an office full of extroverts.
I came across this article:
http://www.psychologytoday.com/print/46944 that summed things up quite well for me.
As a lot of you can probably tell, I am highly introverted. I often find being around people to be exhausting unless I'm very comfortable around them, and sometimes even then. I'm not horribly shy, but I do tend to be very quiet. I absolutely love hanging out by myself and am thankful for this fact. This lends itself well to being a writer since I'm comfortable sitting alone and falling back into my own mind to reason out a character or to advance a plot.
All my life I've hung out one on one or in small groups, typically always having a few close friends. Hanging out with people from the boards is really the first time in my life I've every regularly hung out with a group of people (which explains my occasional awkwardness). I never partied in college, and going to dances in high school was pretty much the most uncomfortable atmosphere for me. Living at home in the basement and being unemployed, there are some days I interact only with the cats which suits me just fine. I typically write 10-12 hours a day around whatever distractions the internet provides and I haven't taken a day off from writing or editing since we took my sister to college in August.
The article says that the country is split pretty evenly between introverts and extroverts, but I have a feeling that since this is a message board, we might see a bit more towards the introvert side. I'm curious.