Before I get into specifics of each type of temperament, it's necessary to explain a little bit about each letter combination in MTBI. If you've done Myers-Briggs before, you're probably familiar with what's known as the four dichotomies:

Extroverted / Introverted - [E / I]

Sensing / Intuitive - [S / N]

Thinking / Feeling [T / F]

Perceiving / Judging [P / J]

If you're not familiar with these, or need a refresher, there is a very concise and (as far as I'm concerned) reliable break-down available here on Wikipedia. Each person has a tendency toward one side of each dichotomy, and in the end, his or her personality type is based on the combination of those four tendencies. For example, Raven and I are both INTPs, meaning we are Introverted, Intuitive, Thinking, and Perceiving.

There are sixteen possible combinations, and of these sixteen, they are split into four major temperaments.

According to "Please Understand Me" by David Keirsey, the widest gap in temperament actually comes into play with Sensing versus Intuitive, because this deals with how information is gathered, understood, and interpreted. Considering the overwhelming significance of perception in shaping who we are, it's no surprise that the four temperaments are first divided between Sensing and Intuitive types.

S / N

The Intuitive vs. The Sensing

Within the Four Temperaments, two of the temperaments are "Sensing" types and two are "Intuitive" types. I'll break these down further later on, but I'd like to point out something I find useful for writers in terms of "sensing" versus "intuitive" characters. We can apply the information-gathering and processing methods to characters through the way we use them to show our readers information.

Description and Exposition are two of the major ways in which we give our readers information about the milieu of our story, and ideally this will all come through the lense of character. The type of things our characters notice, think about, and draw conclusions from can give us as much information about them as it does setting.

The best part? It's not something that is likely to register consciously in a reader's mind, but we as writers can utilize it to help differentiate voice.

Sensing Characters

Sensing characters are grounded in the tangible reality and will be much more in tune with their five senses. Bring your powers of descriptiveness to bear on these characters--let them be the eyes, ears, and noses of your world.
When a sensing character walks into a room, they observe everything, giving a more integrated "big picture" view. They might be more likely to notice color-schemes or mismatched furniture
Though everyone gets "hunches" about things, the sensing character is more likely to squash hunches and draw conclusions from what they can see. A sensing character might walk into a room and observe that it is quiet, that everyone is frowning, and that another character has red-rimmed eyes. From these details, the sensing character will deduce that something is rotten in Denmark. They might reference history rather than possibility.

Intuitive Characters

Intuitive characters live in the realm of thought. The are far more likely to get so caught up in a train of thought that they lose track of their surroundings.While less likely to wax eloquent about a sunset or mountain vista, the intuitive character is your ticket into the less-tangible elements of your world. You can use these characters to describe the thought processes of culture, the theory behind your magic system, or to ponder the fate of the universe and their place in it.
When an intuitive character walks into a room, he will focus his attention on a few small details, often missing the forest for the trees.
The intuitive character will "sense that something is wrong" as soon as they enter the room. They will make broader assumptions about the situation based on what is possible, and may have already come up with several theories by the time they get around to gathering the "sensing" clues.

Of course, it's not totally black and white. Sensing characters also get hunches, and intuitive characters also make observations. At least in terms of writing, I think it's fair to say that order is important.

A sensing character would notice what is present and tangible first, possibly referencing history, the things he knows:

The first thing I noticed was the silence, like someone had sucked all the usual chatter from the steel barracks. It wasn't completely unprecedented, of course--we did spend at least some of our time studying--but none of my classmates had books out, and none of them were smiling. Even Amber, whose perpetually-upturned lips gave her the mischievous look of a cat about to pounce, looked pale and grave. What the hell had happened? I scanned quickly, counting. Five. Where was Sean? My stomach turned over, and I placed my hand on the doorframe to steady myself. "Hey," I said, and though I was dreading the answer, forced myself to ask the question hanging in the air. "Where's Sean?"

Contrast that with the same scene, written from the perspective of an intuitive character:

I stopped in the doorway, repelled by the sudden, solid tension that made the air inside the room hard as a titanium slab. My friends sat trapped by that unspoken emotion, suspended in the solidity of it. Frozen. I didn't have to wait for Shannon to turn her red-rimmed eyes on me to feel the static of panic start in the back of my mind. Something awful had happened. Someone from our class, sent to the brig. Or expelled. Or dead. My stomach turned over, and I placed my hand on the doorframe to steady myself. "What happened?" I said, and only as they turned familiar faces on me did I realize who was missing. My voice barely escaped. "Where's Sean?"

Does your idea of the characters come off differently in these two exerpts? What about your feeling about what role the narrator plays in this group? Do these narrators come across as vastly different types of people?

Middle-Ground

Here's a funny anecdote for you: when Adryn first took the test in high school, she came out as an "N". However, in reading the break-down in temperaments, I had the very strong sense that, while Adryn did exhibit a lot of N traits (imaginative, and a lover of fantasy, the theoretical, and the possible), she was also very S.

Adryn's father is about as S as I am N, meaning we rest at opposite ends of the spectrum. Adryn and her father love driving around in the moutnains, seeing gorgeous scenery, eating wonderful food, and getting knee-deep in whatever present, physical experience. They seem to feel closest to each other when sharing experiences. In contrast, I feel closest to Adryn when we are imagining the possible, creating worlds and characters and concepts together, letting our minds spiral out of the realm of what is.

So I read the type descriptions for ESFP and ENFP to try to decide which one she is, to no avail. BOTH types describe her perfectly.

Frustrated, I had Adryn take the test again last week, and she scored:

S: 49%
N: 51%

"I see myself easily in both of these. It's sort of like I have two modes, and I can switch into whichever one suits me better at the time."

Moral of the anecdote: remember that your characters don't have to be completely sensing or completely intuitive. We're all a blend of both, and some of us just have split personalities.

Are you an S or N? How about your characters? How does this affect your writing?