No, I'm not a psychopath, so don't freak out
After months, perhaps even years of trying to decide why I don't say much, I've come to the conclusion that my inability to talk for lengthy amounts of time is due to a complex combination of reasons.
At a very young age, my personality developed in a way that I felt very respectful of my surroundings. Another factor was my desire to just "get by" without upsetting anything or anyone, with as little embarrasment inflicted upon myself as possible.
I made very little effort to make new friends, for fear that I would only endanger my own ego. As a result, I usually only made friends with people that came to me first. From there I would subconsciously determine whether or not I liked them.
If I did like them, I would try to seclude myself with them, and keep myself away from others. With those individuals whom I liked, I would naturally converse with; usually only on a one-on-one basis.
I seldom felt talking in a large group of people for fear that they might not approve of me, or that I might not be heard over all the chatter.
This developed on through middle school where I would occasionally try to make friends with people that seemed cool. Sometimes these people would be from entirely different social groups. (nerds, jocks, stoners etc.) As a result, I would sometimes have to adapt myself to "fit in". And so I became a wanderer, making friends here and there, without any real group to completely be a member of.
Then came High School, which was scary at first, but it was a relief to know so many different people. I found the motivation to try and talk to people more; even those I might not really like all that much.
Now not talking is sort of a bad habit that I can't break, and I usually forget that people can't hear what I'm thinking. If I don't talk to you, it is by no means anything personal. I just like to keep to myself, and say things that actually matter, rather than ramble on about something you don't care about. So if I'm not talking, in truth, I'm just trying to find the words to say; because I really do want in on the conversation. And sometimes I do say something, but people don't hear me, so that is discouraging as well. Try to get me to talk more, and maybe I'll break this crappy habit/personality thing. I really do wish I was more talkative. Sometimes I just don't know what I should say.