Of course each person is a unique combination of spirit, genetics, and experiences. We are influenced by our family, culture, and time in history. Each person is an individual; one of a kind. Within that uniqueness is a sense of commonality. How do you make decisions, input information, use your abilities, and deal with the world?
Do you like to make decisions calmly based solely on logical thought? If so you are what is called a Thinker or T. Is decision making an emotionally laden thought process based on your values? If so you are a Feeler or F. About 75% of American men make decisions based on Thinking, and about 75% of women base their decisions on Feeling. Both are thought processes-- logical, liner thought, and holistic, value based thought. This does not mean that most men do not have feelings or that most women can't think. The men who prefer making decisions based upon their feelings and values and the women who prefer making logical, clear cut decisions may both feel out of step with the majority of their society.
Another choice we make when we are very young is about how we prefer to take in information. Some prefer the information they receive from intuition (N, those feelings and thoughts which suddenly come to your mind), and others regard only the information they receive from their senses (S). It is believed that about 25% of the American people prefer Intuitive input while the other 75% prefer input from their senses. Some people feel that the percentages are more equal, but I don't think there are that many initiatives out there, at least that I have ever met. People who prefer intuition may have difficulty fitting in a sensing dominated culture.
USE OF STRONGEST ABILITY
If you prefer to use your strongest ability in the world of thought, then you are an Introvert or I. If you prefer to use your strongest ability interacting with the world, then you are an Extravert or E.
Being an introvert does not mean that you do not like people. It simply means that you are energized by the world of thought and usually have a tremendous ability to concentrate. Conversely an extravert (I'm using extravert not extrovert as used by Isabel Briggs Myers) is energized by interacting with the world around him and can do so for extended periods of time while an introvert would soon become fatigued since it is not his natural way of dealing with life. Many of the greatest most loving humanitarians have been introverts such as Mother Teresa and Albert Schweitzer. Some of the strongest extraverts are craftsmen who prefer to work with materials instead of people.
HOW YOU DEAL WITH THE WORLD
The other consideration is whether you like to have things decided, organized and settled. If you do, you are a J or Judging person. It does not mean you judge others, just that you prefer to use your decision making function- thinking or feeling; to deal with the would. If you would rather wait to make decisions until you have gathered more information, then you are a P or Perceiving person. It just means that you prefer to use your perceiving function -- Intuition or Sensing; in dealing with the world. You like gathering information and are not anxious to make decisions until all the information is available.
What gets tricky is that introverts prefer to use their strongest ability in the world of thought while extroverts prefer to use their strongest ability in dealing directly with the world around them.
PERSONALITY TYPE CODE
The code is listed Introvert or Extrovert;
perception Intuitive or Sensing;
decision making Thinking or Feeling;
then how they interact with the world -- Judging (Thinking or Feeling) or Perceptive (Intuition or Sensing)
I am an INFJ. There are few of us but we comprise a large percentage of all writers, and counselors, and many musicians, artists and inventors.
I am an introvert. This means that I prefer to use my greatest strength in the world of thought. The J tells that I prefer to interact with the world by making decisions based on my feeling values. I reserve my strongest ability, Intuition to generate new ideas in the mind.
I will be happy to explain more if you have questions.