Healthy INFJ development and age

Type Development and Age

Have you ever wondered about the best way to develop as an INFJ? Have you considered the cognitive functions as a path to self-development? When we learn about our cognitive functions, it's not uncommon to want to develop them all. Being the best version of ourselves must mean perfecting our use of all four of our cognitive functions, right? The short answer is no. :-)

Katharine Cook Briggs and Isabel Briggs Myers, creators of the MBTI® tool, based their work on the theories of Swiss psychiatrist Carl Jung. Jung believed that a person's development was a lifetime process, and that each stage of development focused on different cognitive functions. By understanding his theory of development we can better understand how to use our INFJ cognitive functions to become a fully developed version of ourselves.

Overview of the Theory of Type Development

This theory of type development describes the cognitive function(s) that a person will develop based on their stage of life. This theory (and the MBTI®) is rooted in the belief that we're born with our personality preferences. This means we're born with our preferred set of cognitive functions. Each of the 16 MBTI® types has a dominant, auxiliary, tertiary, and inferior cognitive function. Read What Does INFJ Say About You if you need more information about preferences or cognitive functions.

During childhood, we will spend the majority of our time developing our dominant function. We also spend time with our auxiliary function, but not to the extent of our favorite—our dominant function. This is necessary for the function to become well-developed, trusted, and skilled. Since our dominant function is always our primary, and preferred, function, it automatically receives the majority of our attention. It's comfortable. It's enjoyable. It's the primary way children are cognitively differentiated from each other. The time spent with our dominant function happens unless there's an environmental interference, which we'll talk about toward the end of this article.

At some point in later childhood and into adolescence we start to give more attention to our auxiliary function. We continue to devote most of our time and energy to these two favorite functions (dominant and auxiliary) into adulthood. Because they're the most interesting to us, we may neglect our tertiary and inferior functions to some extent. We use them, of course, but they may also be a source of frustration for us. We may find them less exciting than our favorites! 

At a time in life that Jung called "mid-life," which is widely considered to be around 40 (but could be as early as the early to mid-30s), the theory says we become more interested in our tertiary and inferior functions. Rather than specializing in our dominant and auxiliary functions as we do in childhood and early adulthood, we can become more generalized in the use of our functions at this stage of development. We may also start to find more enjoyment and interest in our tertiary and inferior functions, which may have been very unfulfilling previously. 

There doesn't seem to be agreement on when these stages begin. What we do know for sure is that each person's lifelong development is unique. We also know that a person's age doesn't guarantee that they've reached a specific stage of cognitive development in Jung's theory. The skill with which a person can use all of their functions also varies from person to person. These are additional reasons why I personally feel that it is up to each person to finalize their own best-fit type. There are many factors, including stage of development, that can impact the way our type is expressed.

The environmental influence on the development of cognitive functions

Although this personality type theory maintains that we're born with our preferences, it also acknowledges the impact the environment can have on the expression of those preferences. As I shared in last week's email (see #2 in that article), if a child's environment discourages the use of their dominant function, they'll struggle to feel confident in their preferences. In this state, they may suppress their natural preferences and instead become more skillful in their less preferred functions. This can lead to less overall satisfaction and contentment and they'll be out of touch with their best gift—their dominant function! According to the theory, this doesn't mean their preferences have changed. It means the development of their preferences were derailed by environmental situations.

How does an INFJ progress through the stages of development?

The healthy development of an INFJ would follow the same pattern:

  1. An INFJ in the early stage of life initially focuses on her Introverted Intuition (Ni). It's important for the parent(s) of an INFJ child to encourage and support this growth and development by allowing plenty of alone time. It's important to listen to the child's insights with curiosity.

  2. In later childhood and into adolescence, the INFJ child begins to also focus on the auxiliary function of Extraverted Feeling (Fe). This means that up until our 30s-40s, the primary goal is to develop our Ni and Fe as the perfect balance and complement. Fe encourages us to get out in the world with others, to consider how our decisions will impact others, to navigate conflict, and to maintain a healthy version of harmony (remembering yourself). This function works with Ni by helping us test and clarify our insights.

  3. As a healthy INFJ shifts into her mid-life transition, she would add more focus to her less-preferred functions. This is our tertiary function of Introverted Thinking (Ti) and our inferior function of Extraverted Sensing (Se). This new interest can bring new sources of energy and more fulfillment and satisfaction. For example, she might find logical analysis of problems to be of more interest than before (Ti). Data and facts may hold more importance (Ti). In-the-moment activities using the senses may also hold more appeal. Now she may also have a greater awareness and connection to her physical body.


As you can see, there are many moving pieces that impact how a person's personality type is expressed. While knowing your personality type is very helpful, and can be affirming for us INFJs, the most important piece of development is to know yourself. This starts with paying greater attention to your thoughts and decisions—and the things that influence your thoughts and decisions. Carving out time to be still and reflect is important for this process. You need this time as an introvert, as someone with the dominant function of Introverted Intuition, and as someone who wants to reach the mid-life stage of cognitive development. Be patient with yourself and know that equal use or perfection of all the cognitive functions is not the goal. 


If you're a parent, you have the power to support your kids' dominant cognitive function, and a healthy development of their personality type. If you want to learn how to parent your kids according to their personality type, Susan Storm at PsychologyJunkie has two great courses. There's the Parenting By Personality Master Class and the Parenting By Personality Basics course. I'm an affiliate with Susan so that just means that if you buy a course through those links, I get a portion of the proceeds. It doesn't cost you any more if you purchase through those links. This is one way we support each other's work.