Jonathan Briggs

Personality Typology with MBTI

All models are wrong, but some are useful.

Disclaimer: This is based on information I have collected over the years regarding MBTI. I have no formal training in this area. I have found Objective Personality and Personality Hacker helpful, but I am not associated with them. The Big 5/OCEAN may be scientifically better but I don’t find it as useful. I think it is best to take a test before you care about the results.

MBTI is based on the theories of Carl Jung, a Swiss psychiatrist, concerning psychological types  “Psychological Types.”. It was developed by Katharine Cook Briggs and her daughter, Isabel Briggs Myers during world war 2.

MBTI uses four binary dichotomies to categorise personalities into 16 types. People are uniquely individual and this is a generalisation based on your preferences.


The four dichotomies:

  • Extraversion (E) vs. Introversion (I): How you focus your energy—outward toward people and action, or inward toward thoughts and reflection.
  • Sensing (S) vs. Intuition (N): How you take in information—through concrete facts and details, or through patterns and possibilities.
  • Thinking (T) vs. Feeling (F): How you make decisions—based on logic and analysis, or emotions and values.
  • Judging (J) vs. Perceiving (P): How you approach the world—preferring structure and plans, or flexibility and spontaneity

The test will give you a four letter code that describes your preferences. Now we will use this code to look at your stack of cognitive functions or function stack. Everybody can use every function, but we have preferences.

There are four basic functions, split into two versions each—extraverted (directed outward) and introverted (directed inward):

  1. Sensing (S) – Gathering raw data from the world:
    • Extraverted Sensing (Se): Focuses on the present, real-time sensory details—action, experiences, what’s happening now.
    • Introverted Sensing (Si): Relies on past experiences, memory, and internalized impressions for stability and comparison.
  2. Intuition (N) – Seeing patterns and possibilities:
    • Extraverted Intuition (Ne): Explores ideas, connections, and future potential—brainstorming, “what if?”
    • Introverted Intuition (Ni): Synthesizes insights into a singular vision or gut feeling about where things are headed.
  3. Thinking (T) – Logical decision-making:
    • Extraverted Thinking (Te): Organizes the external world with facts, systems, and efficiency—goal-driven.
    • Introverted Thinking (Ti): Analyzes internally for precision and truth—building personal frameworks.
  4. Feeling (F) – Value-based decision-making:
    • Extraverted Feeling (Fe): Prioritizes harmony, social dynamics, and others’ emotions—people-focused.
    • Introverted Feeling (Fi): Centers on personal values, authenticity, and inner emotional alignment.

Every MBTI type has a function stack with:

  • A Dominant function (your strongest, go-to process).
  • An Auxiliary function (supports the dominant, balances it).
  • A Tertiary function (less developed, emerges later. 10 year old).
  • An Inferior function (weakest, often a blind spot or stress point. 3 year old. Link to the unconscious).

The stack alternates between extraverted and introverted functions, and the auxiliary complements the dominant (e.g., if dominant is Thinking, auxiliary is Feeling or vice versa). For example:

  • INTP: Ti (Dom), Ne (Aux), Si (Tert), Fe (Inf).
    • Leads with internal logic (Ti), supported by exploring ideas (Ne), with memory (Si) and group harmony (Fe) as weaker areas.
  • ESFJ: Fe (Dom), Si (Aux), Ne (Tert), Ti (Inf).
    • Leads with social harmony (Fe), grounded by past experience (Si), with ideas (Ne) and detached logic (Ti) less prominent.

How to decode your code. I’ll start with an extrovert type as it is more straightforward and then will move to an introverted type.

ESFP
With this type it is the perceiving function that is extroverted. So their dominant function is extroverted sensing. So their auxiliary function is introverted feeling. Feeling is a deciding or judging function, so now we will pick the other judging function and make it extroverted. So their tertiary function is extroverted thinking. The inferior function is the complement of their dominant function. In this case it is intuition. So their inferior function is introverted intuition. So ESFP: Se (Dom), Fi (Aux), Te (Tert), Ni (Inf).

INFP
An introvert is different in that we start with their judging function in this case and not their perceiving function. An IxxJ for example, we would start with their perceiving function. So for this personality their dominant function is introverted feeling. So their auxiliary function is the extroverted intuition. Their tertiary function then is introverted sensing and their inferior function is extroverted thinking. So INFP: Fi (Dom), Ne (Aux), Si (Tert), Te (Inf).

This image was produced by the Objective personality team and shows the 16 types function stack. What I like about this image is that it shows the dominant and inferior function on one pole and the auxiliary and tertiary functions on another pole. One of Jung’s understandings was that we can see our auxiliary and tertiary functions, but can’t always see our dominant and inferior function. Our dominant function is our go to. We use it and abuse it without knowing. Our inferior function is neglected. Often the bad or recurring problems in our lives are a result of neglecting this function. For example, the person who is dominant in Ne or Se is so addicted to new and novel and are not narrowing down this new information, that they force others (Ni or Si) to control them.  A selfish Fi or Ti  person who is so overconfident in their way, forces the tribe Fe or Te  to finally kick them out.  People’s lives are defined by how they are going to “save the world” if they were just allowed to do more of their dominant function.

Detour – Human Needs

Tony Robbins identifies six core human needs that drive human behavior: Certainty, Uncertainty/Variety, Significance, Love/Connection, Growth, and Contribution. 

Here’s a breakdown of each need: 

  • Certainty: The need for safety, stability, comfort, order, control, and consistency.
  • Uncertainty/Variety: The need for the unknown, change, new stimuli, and adventure.
  • Significance: The need to feel unique, important, special, or needed.
  • Love/Connection: The need for a strong feeling of closeness or union with someone or something.
  • Growth: The need for expansion of capacity, capability, or understanding.
  • Contribution: The need for a sense of service and focus on helping, giving to, and supporting others.

The Objective Personality team noticed that there is a direct overlap with the first four human needs and Jung’s 8 functions

  • Certainty –IxxJ
    • Ni: Finds safety and security in personal, limited, conceptual, abstract understandings
    • Si: Finds safety and security in personal, limited, proven, real, physical structure
  • Uncertainty/Variety – ExxP
    • Ne: Seeks out more, new, better, interesting patterns, connections and understandings
    • Se: Seeks out more, new, better, cool experiences, facts and things that have happened
  • Significance – IxxP
    • Fi: Responsible for holding self to the standard of what they love and value
    • Ti: Responsible for holding self to the standard of what is true and works
  • Love/Connection – ExxJ
    • Fe: Respects the spectrum of values and feelings of the tribe
    • Te: Respects the spectrum of reasons and what works for the tribe

Again we have two poles or dimensions that are in tension. The need for certainty and the need for variety. Then the need to be an individual and the need to be part of a tribe.

Detour – Eight function Model

John Beebe is a Jungian analyst who developed the eight-function model as an extension of the Myers-Briggs Type Indicator (MBTI) and Carl Jung’s theories. This model builds on the standard four function stack (dominant, auxiliary, tertiary, inferior) by incorporating the “shadow” functions, bringing the total to eight and assigning each a unique archetypal role.

As seen above Jung identified four functions (Sensing, Intuition, Thinking, Feeling), each with an extraverted or introverted attitude, making eight function-attitudes (e.g., extraverted Sensing = Se, introverted Sensing = Si). The classic MBTI model gives you a stack of four based on your type, like INTP being Ti-Ne-Si-Fe. Beebe’s innovation was to say, “You don’t just use four; all eight are in there, playing specific roles in your psyche.” The first four are conscious (ego-aligned), and the last four are unconscious “shadow” functions, often surfacing under

The Eight Functions and Their Archetypes:
Beebe paired each function position with a Jungian archetype, reflecting its psychological role. The order depends on your MBTI type, with the shadow functions mirroring the primary ones but flipped in attitude (introverted becomes extraverted, and vice versa). Here’s how it works, using INTP (Ti-Ne-Si-Fe) as an example:

  1. Hero/Heroine (Dominant): The strongest function, your core identity.
    • INTP: Ti (introverted Thinking) – The “hero” is a logical problem-solver, seeking internal clarity.
    • Role: Confidently leads your personality, like a protagonist driving the story.
  2. Good Parent (Auxiliary): Supports the hero, nurtures yourself and others.
    • INTP: Ne (extraverted Intuition) – Explores possibilities, offers creative guidance.
    • Role: A wise, protective figure, balancing the hero’s focus.
  3. Eternal Child (Tertiary): Playful, vulnerable, less mature but endearing.
    • INTP: Si (introverted Sensing) – Ties to memory and tradition, sometimes nostalgic or stubborn.
    • Role: The innocent kid in you, seeking comfort or resisting change.
  4. Anima/Animus (Inferior): The aspirational yet tricky bridge to the unconscious.
    • INTP: Fe (extraverted Feeling) – Struggles with social harmony, but yearns to connect.
    • Role: The soulful opposite-gender figure, pulling you toward growth or chaos.

Now the shadow functions (5-8), which oppose or challenge the first four:

  1. Opposing Personality (Shadow of 1): Resists the hero, often contrarian.
    • INTP: Te (extraverted Thinking) – Pushes external logic or efficiency, clashing with Ti’s depth.
    • Role: The antagonist, popping up to argue or disrupt when the hero’s too rigid.
  2. Witch/Senex (Shadow of 2): Critical, controlling, a dark twist on the parent.
    • INTP: Ni (introverted Intuition) – Fixates on visions or fears, undermining Ne’s openness.
    • Role: The harsh elder, judgmental or obsessive when you’re off-balance.
  3. Trickster (Shadow of 3): Deceptive, playful, ties you in knots.
    • INTP: Se (extraverted Sensing) – Overreacts to the moment, tripping up Si’s stability.
    • Role: The mischievous imp, causing trouble or dodging responsibility.
  4. Demon/Daimon (Shadow of 4): The deepest shadow, destructive or transformative.
    • INTP: Fi (introverted Feeling) – Unseen values or emotional outbursts sabotage Fe’s harmony.
    • Role: The devilish force, either wrecking things or hinting at profound change.

How It Works:

  • Primary Stack (1-4): These are your conscious tools, aligned with your ego. For INTP, Ti-Ne-Si-Fe is the familiar territory—logic, ideas, memory, and shaky social skills.
  • Shadow Stack (5-8): These are less conscious, often repressed, but they still influence you. They’re the flipped versions of your primary functions (e.g., Ti’s shadow is Te). They show up in stress, defensiveness, or blind spots—like an INTP getting bossy (Te) or paranoid (Ni).
  • Archetypes: Beebe’s twist is tying these to universal roles (hero, trickster, etc.), making it less about “skills” and more about the story your psyche tells. The shadow isn’t just weak functions; it’s where your unconscious dramas play out.

Example in Action:

Imagine an INTP facing a group project:

  • Ti (Hero): I analyze the problem logically, crafting a perfect plan in my head.
  • Ne (Parent): I brainstorm wild ideas to help the team.
  • Si (Child): I cling to “how we’ve always done it” if stressed.
  • Fe (Anima): I fumble awkward small talk, wanting approval but unsure how.
  • Te (Opposing): I snap at someone for sloppy execution, annoyed by inefficiency.
  • Ni (Witch): I fixate on a vague hunch the project will fail.
  • Se (Trickster): I miss a deadline because I got distracted by something shiny.
  • Fi (Demon): I sulk privately, feeling misunderstood, until it bursts out as sarcasm.