Back in 2001, my colleagues and I took the Myers-Briggs Type Indicator test (MBTI). (For what it's worth, the only person whose personality type was the same as mine was the receptionist.) My type was found to be ISFP. You may or may not be familiar with the Myers-Briggs classifications; I won't take the time or space to get into it in detail (other than what my type says about me) but feel free to browse the Wikipedia entry.
As one can imagine, each MBTI personality type comprises four distinct components. Each individual component reflects one of two poles, and where one score along the pole's continuum determines which end you are. They are as follows (my poles in bold):
Extraversion (E) vs. Introversion (I)
Sensing (S) vs. Intuition (N)
Thinking (T) vs. Feeling (F)
Judging (J) vs. Perceiving (P)
If you prefer Extraversion, you focus on the outside world to get energy through interacting with people and/or doing things.
If you prefer Introversion (as I do), you focus on the inner world and get energy through reflecting on information, ideas, and/or concepts.
If you prefer Sensing (as I do), you notice and trust facts, details, and present realities.
If you prefer Intuition, you attend to and trust interrelationships, theories, and future possibilities.
If you prefer Thinking, you make decisions using logical, objective analysis.
If you prefer Feeling (as I do), you make decisions to create harmony by applying person-centered values.
If you prefer Judging, you tend to be organized and orderly and to make decisions quickly.
If you prefer Perceiving (as I do), you tend to be flexible and adaptable and to keep your options open as long as possible.
According to my report, ISFP people typically care deeply about what they do, more likely showing this through deeds than words. They are loyal to people, ideals, and organizations they care about. They have a great deal of warmth, although they don't always display it. ISFPs tend to be tolerant, open-minded, and adaptable, taking things as they come. However, when something important to them is threatened, they do not give in. They have little need to impress or dominate others. They care about having people get along and may be the glue that holds things together. People can count on them to notice what needs to be done and proceeed simply and without fuss.
Additionally, according to the detailed analysis I received, I am most strongly I and F, firmly P, and mostly S, though there are aspects of N and to a much lesser extent J in my overall profile. It's important to note that some aspects of all the poles are in each person's personality, though some are much preferred.
Here are some individual characteristics that correspond with each letter:
I = Receiving, Contained, Intimate, Reflective, Quiet
S = Concrete, Realistic, Practical, Experiential, Traditional
F = Empathetic, Compassionate, Accommodating, Accepting, Tender
P = Casual, Open-ended, Pressure-prompted, Spontaneous, Emergent
Because these scores and classifications are based on questionnaire responses, they feel very right to me. Furthermore, when I look at the other personality types, I find them not only foreign but also less desirable to me. ISFP fits me well, and I can't imagine being anything else. I guess if I could, I would be it.
The takeaway, I suppose, is that each of us is wired in a certain way, and when it can be codified it can more easily be understood, even tolerated. Sometimes what we find annoying or displeasing in another person is simply his or her different way of expressing that part of their personality. If I can keep in mind that chatty people "get energy through interacting with people" and are not just out to drive me nuts with their incessant jabbering, I can at least learn to respect their different approach to a common need. That I get my energy in a different way doesn't make me better (though to my mind it's more comfortable), it's just another way to do it.