And things can change with age. The chart and info below show how personality types can be in the same group of 4, but different Dominant, Secondary, Tertiary and Inferior Functions. Notice that the J/P axis does not play into the order of these. Also notice that the 1st & 4th, 2nd & 3rd are opposites. Showing how people grow to learn to fill in their talents that they don’t develope early on. The 4th or Inferior Function, will manifest itself later in life, often biting you in the but, because you learn to do it, but you don’t prefer it, you sabotage yourself this way subconciously.
So a T type may learn to use F type skills between ages 20-35, or may get beat up by them if they are Inferior. So there may be 2 types of the N-S, F-T axis. because the one you have as your Dominant is probably more important than your Secondary, because your secondary is complemented by it’s opposite in the the 20’s-30’s. The Dominant 1st, it plays the guitar solo, and never learns to get along with it’s opposite, until it’s too late. Also Note the differing Introvert/Extrovert notation. Those who have an Extrovert personality type will have their Dominant Function be Extroverted, but their 2nd/3rd Functions will be the opposite, Introverted. The same scenario with Introverts, their 2nd/3rd Functios will be Extroverted, depicted by the “e” or “i” in the chart below. This illuminates that extroverts have introverted parts/processes going on as well as extroverted, and it varies based on Type.
Age 0-2 years, nothing conclusive can be said about the child’s personality.
Age 2-6 years, some children can be identified on I/E and P/J, giving 4 different personlity types: EP, EJ, IP, IJ.
Age 6-12 years, it is also possible to identify one more parameter, giving 8 personality types. This provides the dominant preference.
At age 20-35, most people have started to use a tertiary function, improving their skills.
At age 35-50, a fourth function (inferior preference) is starting to be used more frequently. This arrival of a fourth function seems to be closely related to the phenomenon named Midlife Crisis.
this chart is taken from ]Myers-Briggs Type Indicator - a knol by Lars Dybdahl\ (http://knol.google.com/k/myers-briggs-type-indicator)
Personality Type: 1st/Dominant 2nd/Auxiliary 3rd/Tertiary 4th/Inferior
ISTJ: iS eT iF eN [Gaurdian]
ISFJ: iS eF iT eN [Gaurdian]
ESTP: eS iT eF iN [Artisan]
ESFP: eS iF eT iN [Artisan]
INFP: iF eN iS eT [Idealist]
ISFP: iF eS iN eT [Artisan]
ENFJ: eF iN eS iT [Idealist]
ESFJ: eF iS eN iT [Gaurdian]
INTP: iT eN iS eF [Rational]
ISTP: iT eS iN eF [Artisan]
ENTJ: eT iN eS iF [Rational]
ESTJ: eT iS eN iF [Gaurdian]
INTJ: iN eT iF eS [Rational]
INFJ: iN eF iT eS [Idealist]
ENTP: eN iT eF iS [Rational]
ENFP: eN iF eT iS [Idealist]