Most of us have taken that Myers-Briggs personality test at some point in our lives and if you've taken it, you know the first classifcation you receive is whether you are an introvert or an extrovert.
Ally Sheedy's character in The Breakfast Club=introvert
Ryan on the O.C=introvert
You get the picture. This test claims that we are all either one or the other.
Though I've been classified an introvert, I think I definitely tend to switch between the two depending on the social situation. But there are definitely times I wish I could draw more on the extrovert in me, and this article actually gives some great tips on how to bring out the "inner extrovert" in us all.