The other day at our small group dinner, one of our group members who is pretty new made the following joking observation to me. "You and your husband both talk a lot. Which one of you talks more when you're alone?"
I was surprised by her perception, but when I thought about it, I realized that it was accurate given her exposure to me. She sees me almost exclusively in the context of our small group. I *do* talk a lot at small group. For one thing, I enjoy the company of these particular people! In groups whose conversation is less interesting, I won't talk much at all.
In fact, I'm a pretty quiet person most of the time. Literally. I spend hours per day working alone on one project or another. Some are exciting (novels), others mundane (paying bills and doing laundry). But the vast majority of the time, I'm by myself.
This doesn't bother me usually. Hardly ever, now that I have friends in town and internet friends. It disturbed me when we first moved here, but that's because I felt that my solitude was involuntary. Now, it feels like a choice that I make in order to do the work that must be done. And though my Myers-Briggs test says that I am half-introvert, half extrovert, I'm actually an introvert by the other Myers-Briggs definition. That is to say, I derive my energy from my "alone" time, and I become exhausted by too many consecutive hours in the company of others.
My husband, by contrast, is a true extrovert. He derives his energy from contact with other people. He and his family can hang out and talk for ten hours straight. My husband is happy to talk at almost any time. He's a salesman, and he can go out and talk all day for a living and then come home and talk some more without any trouble at all.
So here we are as we appear to our small group, two "characters" displaying the same behavior: love of conversation. Yet, our personalities and our lifestyles are very different. In that situation, he talks a lot because he just loves to socialize. I talk a lot because all my social energy is ramped up by my long, silent hours of work.
It's a great example of the difference between behavior and personality. Characterization in fiction is so complex: it's no wonder we hardly ever get it right for every character in the first draft. I'm in my twelfth chapter and still trying to figure out one aspect of my heroine's personality.