Yes, we're all born with one personality type which we have our entire lives. But as we grow older and have new life experiences – especially important ones like births, deaths, schooling, becoming parents and working – we grow and develop different aspects of our personalities. And although no one can know what the future holds, there is a somewhat predictable blueprint for how we may change over time. 

Here’s a glimpse of what the future YOU may be like.

Personality Type: A Developmental Model

One of the many aspects of the Jung/Myers model of personality type that makes it so rich and valuable, is that it is a developmental model, rather than a static one.

Isabel Myers introduced the idea that there is a hierarchy to the type “functions” that Carl Jung originated. She labeled them – from most to least important – the Dominant, Auxiliary, Third and Fourth (or “Inferior”). These are always the middle two letters of a person’s type: Sensing, Intuition, Thinking or Feeling.

An early user of personality type, W. Harold Grant, theorized that there is a timeline for which most people naturally develop these four different functions, based on their age. But because every individual is unique and has different life experiences, the age ranges can vary significantly. So, before I present the timeline for when you might develop these different functions, let’s take a few minutes to see if you can identify your type’s hierarchy.

The Type Hierarchy: Who’s on First?

Below is a list of the Dominant, Auxiliary, Third and Fourth functions for all 16 types, organized by the four Temperament groups.

Traditionalists (Sensor Judgers or SJs)

ESTJ: Thinking, Sensing, Intuition, Feeling

ISTJ:  Sensing, Thinking, Feeling, Intuition

ESFJ: Feeling, Sensing, Intuition, Thinking

ISFJ: Sensing, Feeling, Thinking, Intuition

Experiencers (Sensor Perceivers or SPs)

ESTP: Sensing, Thinking, Feeling, Intuition

ISFP: Feeling, Sensing, Intuition, Thinking

ESFP: Sensing, Feeling, Thinking, Intuition

ISFP: Feeling, Sensing, Intuition, Thinking

Conceptualizers (Intuitive Thinkers or NTs)

ENTJ: Thinking, Intuition, Sensing, Feeling

INTJ: Intuition, Thinking, Feeling, Sensing

ENTP: Intuition, Thinking, Feeling, Sensing

INTP: Thinking, Intuition, Sensing, Feeling

Idealists (Intuitive Feelers or NFs)

ENFJ: Feeling, Intuition, Sensing, Thinking

INFJ: Intuition, Feeling, Thinking, Sensing

ENFP: Intuition, Feeling, Thinking, Sensing

INFP: Feeling, Intuition, Sensing, Thinking

Where Are You in YOUR Type Development?

Serious students of personality type will notice that the age ranges presented below are slightly different from those offered by Grant. This is based on decades of experience and research conducted in writing the book Nurture by Nature (which provides a more in-depth discussion).

From birth to age 6

Because young children are undifferentiated, it’s often hard to identify their whole types, though some characteristics – like Extraversion and Introversion – are usually much easier to determine.

From age 6 to age 12

Most parents will probably agree this is the time when their child’s personality really starts to emerge and their Dominant function is often on display. A dominant Sensor may show an inclination for mastering skillful gymnastic routines; a Dominant Intuitive may create surprising musical instruments out of household odds and ends; a dominant Thinker may construct impressive arguments against being punished; a Dominant Feeler may demonstrate concern and empathy for others.

From age 12 to age 25

This is the time when people start to develop their Auxiliary function, which provides balance for Dominant. For example, if the Dominant is either Sensing or Intuition (the two different ways people take in information), the Auxiliary will be either Thinking or Feeling (the two ways that people primarily make decisions).

From age 25 to age 50

At some point after the age of 25, we start to develop our third function (sometimes called the “Tertiary”).  We’ve found that most people don’t start to do this in earnest, or with great success, until closer to the age 40 or even later. You’d notice that this timing coincides with another phenomenon that often occurs around this time: the midlife crisis. I don’t think the connection between type development and a midlife crisis (or midlife “reevaluation”) is merely coincidental.

Carl Jung – the father of Personality Type – said that as we reach midlife, we unconsciously begin to seek wholeness, because we realize our journey will not go on forever. And how do we achieve this wholeness? By engaging the parts of our personality that we didn’t use much in the first half of our lives – our third and fourth functions.

Marty is an ESFJ. His dominant is Feeling, his auxiliary is Sensing, his third function is Intuition, and his fourth function is Thinking. Marty has spent the first 45 years of his life acting very “true to his type”. Most people would describe him as friendly, helpful…a really nice guy always eager to help people in real ways, and someone who accepts most things at face value. Only recently, Marty has become interested in seeking deeper meaning. Instead of primarily being interested in “what is happening,” he wants to know “why.” This is solid evidence that he is developing his third function Intuition.

After 50

Later in life, most of us start to use our fourth function with greater success.   Some students of Personality Type believe that the fourth function is so unconscious that it remains unavailable to most people, but I believe that we can gain greater access to our fourth function, and like a muscle – the more we use it, the stronger it will become.

Marian was 62 when she got picked to serve on a jury hearing a medical malpractice case. An ENFP, Marian’s dominant is Intuition, her auxiliary is Feeling, her third is Thinking and fourth, Sensing. Normally an ENFP would be a “dream juror” for the plaintiff (the person bringing the lawsuit) because they are so empathetic and eager to help people – especially those who are suffering.

After two weeks of hearing testimony, Marian was still sympathetic to the plaintiff’s plight, but because she now had greater access to her fourth function Sensing, she was a much different juror than she would have been 10 years ago. Not only was she more interested in the facts and specifics of the case – things she would likely have glossed over in the past – but since she had worked on developing her third function Thinking, she was also able to be more objective.

What Does Type Development Look Like?

If you are developing your Sensing, you may:

  • Become more aware of how things look, sound, smell, taste and feel
  • Develop a new appreciation for nature
  • Find yourself paying more attention to details in general
  • Become more grounded and realistic and less idealistic
  • Enjoy physical activities such as cooking, building, painting, listening to music, hiking, gardening, etc.  

If you are developing your Intuition, you may:

  • Become more open to change and seeing things in new ways
  • Become more interested in understanding and looking for the underlying meaning
  • Find yourself using your imagination more
  • Ask more “why” questions, and see more clearly how things are related to each other
  • Develop a new interest in art, religion, research, learning new things, brainstorming, creative writing, reading fiction, traveling and immersing yourself in different cultures

If you are developing your Thinking, you may:

  • Make decisions more objectively and take things less personally
  • Place a greater emphasis on fairness and equality
  • Be more direct and honest with others
  • Develop more sophisticated critical thinking skills
  • Become interested in the rights of others, negotiating, strategy games, debating, politics, being a more careful consumer

If you are developing your Feeling, you may:

  • Become more sensitive to how your actions affect others
  • Become more in touch with your own and others’ feelings
  • Be more interested in cultivating and nurturing friendships
  • Become a better listener
  • Volunteer to help others, attend reunions, keep a journal, meditate, more easily show appreciation and express gratitude, engage in therapy

To Sum Up

Type development is an important component of the Jung/Myers Model of Personality Type. Some of our type preferences are more dominant and central to who we are than others, but the greatest growth comes from being able to access our less developed (third and fourth) functions.

There appears to be a “rough” timeline for developing the four functions – Sensing, Intuition, Thinking and Feeling – that comprise each person’s type. Being aware of which components of your personality type come most and least naturally to you can help you develop new competencies and result in greater personal and professional satisfaction.

This is Part 1 of my Future You series. Next week, I'll be digging deeper into what the future you might look like with a focus on career development. Please share your experiences in the comments!  

Paul Tieger
Paul D. Tieger is the Founder and CEO of SpeedReading People, LLC. He is an internationally recognized expert on – and author of five breakthrough books about – personality type including The Art of SpeedReading People and the one-million copy best-seller Do What You Are. A jury consultant for twenty-five years, Paul pioneered the use of Personality Type to help trial attorneys understand and communicate with jurors and has worked on dozens of high profile civil and criminal cases including the first physician-assisted suicide trial of Dr. Jack Kevorkian. Paul holds a BS degree in Psychology and an MS in Organizational Behavior.