The Myers-Briggs Types

The Myers-Briggs Personality Types Indicator (MBTI) has been in use since the 1940's. This test has been used in many industries and career counselors alike.
The way the MBTI works on a series of questions (98-88) and identifies the individual's natural way of doing  things. The answers are then analysed against 4 sets of opposite preferences, this forms 16 different personality types.

Preferences 

Get Energy; Extraversion (E) vs. Introversion (I)

Individuals that prefer to focus on the outer world of people and activities will lean towards the extraversion. These individuals will project their own energy outwards along with gaining their energy from interactions with others. The introvert will focus their energy inward on their own ideas and experiences, they gain ebergy form reflection. 

Taking in Information; Sensing (S) vs. Intuition (N)

Taking in information that is real and tangible and being observant about specifications of what is going on around will be in the sensing category. These  Individuals are attuned to practical realities. The intuition segment will look at the big picture with a focus on relationships and connections between the facts. These individuals are good at seeing new possibilities. 

Making Decisions; Thinking (T) vs. Feeling (F)

Making a decision based on logical consequences of a action or choice will make that individual a thinker. The thinking group will try and find a standard or principle that will apply in all similar situations. Preferring feeling leads one to make decisions based on personal values and what is important to them and others involved. 

Deal With Outer World; Judging (J) vs. Perceiving (P)

The preference for judging will live in a controlled world with structure and order. They live in the outer world in a planned, orderly way. They make decisions and move on with closure. Perceiving preference will live in the outer world with flexibility and in a spontaneous way.They want to experience life rather then control it. 

Since 16 different types of personalities is difficult and time consuming knowing the types that are common among other negotiators is useful. I would argue that Personalities in the ESTJ, ESFP, and ENTJ areas will most commonly be negotiators. But since sometimes individuals are forced or the only one to negotiate is will be wise to research they types you will presume that individual to be.

Knowing your own MBTI is important. If you are one that makes emotional gut decisions you may want a person that is more sensing and thinking to even you out. If you are that introvert thinker you may want someone that can make decisions fast and accurately.

Aranda, Richard, and Stan TiLton. "Myers-Briggs Personality Preferences May Enhance Physician Leadership Success In Non-Clinical Jobs." Physician Executive 39.3 (2013): 14-22. Business Source Premier. Web. 5 June 2013.