Development of personality type

There has been much research into changes over time of personality type.

The most plausible hypithesis is that there is a pre-defined order in which we develop the four functions (Sensing, iNtuition, Thinking and Feeling) as much as we have a preference in using them.

The model identifies our strongest (dominant) and secondary function. These are the two letters in the middle of our type. The last letter (P or J) tells us which of them is applied to the external world. For an Extravert, it will be the dominant function. For an Intravert it will be the secondary. The other one is applied in an Intraverted context and is secondary for the Extravert and dominant for the Intravert. In our development, we first develop the dominant and then the secondary function on our way to adulthood.

The tertiary function is the one opposed to the secondary. Most of us discover it around the age of thirty, some earlier and some later.A few never really develop the tertiary function.

The last function (inferior) is fully developed only by a few lucky individuals in the later stages of their life.

The sequence of the functions that are developed is pre-defined, but not the timing. Over a normal lifespan, most people will develop the dominant, secondary and tertiary functions, leaving the inferior one dormant.

Four examples of sequences for four types: