I am not sure whether I am an extrovert or introvert. Numerous personality tests have given both results. Even Myers-Briggs test, whenever I take it, I either get an ENFJ or INFJ. Some people like to call themselves ambiverts - maybe that is what I am.
I am no psychologist but I would like to point out two reasons why people often think (maybe correctly) that I am an introvert. It is not because I am shy, reserved, or people hating. One conventional reason that defines introvert which applies to me as well is that I need time to recharge alone even though I like hanging out with people. I need that break! However, there is another reason that to the best of my knowledge has not been explored.
The other reason is that I am totally fine with lulls in conversation. I don't feel the desperate need to fill the silences when I am hanging out with someone. For example, I have had torturous times going on long drives with extroverts because they always have to say something. I don't find it necessary. I can have a fun time hanging out with my introvert friends which includes times when all of us are silent.
The problem with having to say something throughout is that it leads to either gossipy conversations, repetitive talking points, stating the obvious, or just picking apart the weather. It also puts too much pressure on me when after a period of me being quiet (and being fine with it), I am categorized as shy, meek, or in some cases arrogant. Although I have outgrown being made to feel guilty about being quiet, it still stings when people point it out.
I don't like overused quotes but I am going to end with one - "Wise people talk when they have something to say. Fools talk when they have to say something.