MBTI preferences and cognitive functions, reading notes on My True Type

These are reading notes from the Dwarves research vault on Dr. A.J. Drenth's My True Type: Clarifying Your Personality Type, Preferences & Functions. Page ranges point back to the book. Other notes draw on Personality Junkie, 16Personalities, Practical Typing and David Keirsey's work on temperaments. The order follows the book: what a type is, the four preference pairs, the eight cognitive functions, how to confirm a type, and a team-level view. Several source notes were written in Vietnamese, and this page carries them in English.

For a hiring-side application, see Apply MBTI in hiring.

1What a type is

Learning your personality type (PT) gives you two things. You understand yourself and others better, including how people tend to interact and think. And you get insight that helps clarify a life path, career included. No personality type is inherently better or more desirable than another.

A type is four preferences. There are eight preferences in total, divided into four dichotomies:

Two options in each of four positions gives 2 x 2 x 2 x 2 = 16 personality types in MBTI.

2Type versus trait

The Myers-Briggs Type Indicator draws on the 1920s theory of the psychologist Carl Jung. Other frameworks followed over the next decades, and the most important of them is the Big Five personality traits.

The two models count differently. With a type, whichever side of a dichotomy scores above 50% gives you that label. A trait is based on the degree of each quality, and it does not divide people into categories.

3The Big Five (OCEAN)

The test on 16Personalities also blends in the Big Five, so its result often carries five letters. The five traits:

• Openness: imagination and insight. Do you like new things and abstract concepts, and do you have many interests?
• Conscientiousness: your attitude when you work on a task. Do you prepare and plan ahead, do you attend to detail, and are you often late on deadlines?
• Extraversion
• Agreeableness: empathy, care, and willingness to help other people.
• Neuroticism: how you control your mood and cope with stress.

Two notes. A person's traits can change with age, and they are heritable. And behavior is the person's underlying personality plus situational variables.

4The four preference pairs

Drenth covers the four pairs on pages 24 to 57. The lists below restate his points in short form. Where he ties a trait to particular types, such as IJs or EPs, the list says so.

4.1Introversion and extraversion

Pages 24 to 32.

Introverts:

• Look inward and focus on themselves
• Think independently
• Weigh things carefully and lean conservative and selective; they plan before they move, IJs most of all
• Favor a slower, quieter life with room to reflect
• Get overwhelmed by outside stimulation more easily
• Can feel out of place, uneasy or not up to the world
• Often talk less, ISPs most
• Know their own inner state well
• Need more time alone

Extraverts:

• Look outward at the world
• Think more as part of a group
• Lean toward "act now, think later" (pp. 24 to 32), EPs most, and tolerate risk and assertiveness more
• Like a busy life on the move
• Worry less about being harmed or swamped by the world
• Feel at home in it
• Often talk more, ENJs most
• Know the world around them well
• Need less time alone

4.2Intuition and sensing

Pages 33 to 38.

Sensors:

• Get absorbed in living and can forget to reflect on it, ESPs most
• Do their best work on practical, hands-on tasks and handle details and daily affairs well
• Split by subtype: SPs love new sights, tastes and sensations, while SJs prefer routine and tradition
• Care more about facts and particulars than about how they connect
• Work best at the back end of the creative process, where ideas get carried out

Intuitives:

• Often sit deep in thought, with the mind elsewhere
• Can struggle with the concrete details of daily life, INJs and ENPs most
• Prefer theoretical, imaginative or speculative ground and enjoy working with ideas
• Like abstract patterns, connections and languages, whether verbal, mathematical or computer-based
• Care more about the links between things, abstract things especially, than about the things themselves
• Work best at the front end of the creative process, where ideas and insights get generated

4.3Thinking and feeling

Pages 39 to 45.

Thinkers:

• Reason and decide on logic
• Focus on logic, strategy, logistics, utility, function and classification, and try to make things more useful, rational and efficient
• Step back from their emotions more easily and decide in an impersonal way
• Pay less attention to the needs and feelings of others
• Concentrate on their own work and interests

Feelers:

• Bring taste and feeling into reasoning and decisions
• Fill life with colors, sounds, flavors, scents, textures, stories and images
• Tune in more closely to feelings, their own and other people's
• Tend to be caring, compassionate and nurturing
• Spread their time across work, relationships and caregiving

4.4Perceiving and judging

Pages 46 to 57.

J types:

• Come across as firm, direct and opinionated
• State their views and wishes plainly, EJs most, and speak in declarative sentences
• Signal closure, seriousness or formality through tone and manner
• Get asked by others for answers and decisions
• Treat planning as a way to cut risk and secure good outcomes
• Hold converging beliefs and a settled worldview, and show it
• Prefer structure and predictability at work
• Favor traditional teaching and learning, such as lectures and direct instruction
• Are not necessarily neat, tidy, organized, uptight or punctual
• Need less variety to stay stimulated and feel less restless, IJs most

P types:

• Come across as open, receptive and adaptable
• Can hold back from saying things directly, IPs most, and tend to hint or ask questions instead
• Dislike detailed plans, especially ones that involve other people, and like leaving things open
• Take a long time to settle beliefs or decisions
• Often earn a reputation as good, non-judgmental listeners
• May doubt external rules and prefer to set and follow their own
• Want variety, novelty, informality and little structure at work
• Often teach themselves, IPs most, and teach others by example or by facilitating
• Are not necessarily messy, disorganized, procrastinating or late
• Often feel restless and chase a wide range of activities for stimulation, EPs most

5Cognitive functions

5.1Why look at functions

A personality type only shows the surface. Take an INFP. The full description on 16Personalities lists the four letters: introverted, intuitive, feeling, perceiving. That does not say what drives those traits, why a type behaves as it does, or which further habits and tendencies it has. Cognitive functions answer those questions.

5.2The eight functions

The eight functions follow from the eight preferences (I, E, N, S, T, F, P, J).

Split by orientation, which is whether the function shows outward:

• Introverted (does not show outward): Ni, Si, Ti, Fi
• Extraverted (shows outward): Ne, Se, Te, Fe

Split by purpose, which is how a function takes in or processes information:

• Perceiving (taking in information): Ni, Ne, Si, Se
• Judging (processing information): Ti, Te, Fi, Fe

5.3The function stack

Each type is built from four functions, called its cognitive function stack. They sit in four layers from strongest to weakest:

1. Dominant
2. Auxiliary
3. Tertiary
4. Inferior

Every type has one fixed stack, and it does not change. The first two layers, dominant and auxiliary, show most clearly, and they are what other people see. The tertiary and inferior layers show weaknesses and blind spots, which is what we need to improve to reach satisfaction and balance in life. An INFP's stack is Fi, Ne, Si, Te.

5.4Working out the stack

1. The first letter (I or E) sets the orientation pattern of the four functions. An Exxx type runs E-I-E-I. An Ixxx type runs I-E-I-E. An E type shows its strongest function outward, so the signature trait is what outsiders see. For an I type the signature trait stays inside, and outsiders see the auxiliary function.
2. The second letter (N or S) and third letter (F or T) name the first two functions. xNFx gives N and F. xSTx gives S and T.
3. The last letter (P or J) says whether the first extraverted function perceives or judges. An xxxP type has Ne or Se as one of its first two functions. An xxxJ type has Te or Fe.

Opposite positions in a stack pair up: dominant with inferior, auxiliary with tertiary. Four function pairs oppose each other:

• Si and Ne
• Ni and Se
• Ti and Fe
• Fi and Te

A stack is two such pairs. Each function behaves differently depending on its position, strong or weak, and the combination forms the inner world of that type. Worked example for an ENFJ: Fe, Ni, Se, Ti.

6The eight functions in profile

Each profile restates Drenth's description of the function at the page range given. The names in the lists of famous examples are his.

6.1Introverted intuition (Ni)

Pages 58 to 69.

• Role: gathers conscious and subconscious information and synthesizes it into impressions, insights, answers and theories, looking for the deep causes, patterns and laws behind what the senses report
• Most common in INTJs and INFJs, and also strong in ENTJs and ENFJs
• Shows up as deep perceptiveness, a sense of simply knowing, theoretical brilliance, strong analysis and focus, and a knack for advising and troubleshooting
• Famous INJs: Plato, Jesus, Nietzsche, Jung, Stephen Hawking

Ni is the rarest of the eight functions, and a note in Vietnamese describes it as carrying a "signal from the universe." Ni users are good at sensing the "dark skies before the storm" (pp. 58 to 69). They like to explore the submerged part of the iceberg in a problem.

6.2Extraverted intuition (Ne)

Pages 70 to 78. Practical Typing has a longer comparison: 7 differences between Ne and Ni users.

• Role: explores widely, pulls ideas together and voices associations and possibilities
• Most common in ENTPs and ENFPs, and also strong in INTPs and INFPs
• Shows up as brainstorming, inventive, artistic and idea-driven creativity, divergent thinking, web-like association, and a nose for promising new ventures
• Famous ENPs: Benjamin Franklin, Walt Disney, Steve Jobs, Ellen DeGeneres, Jon Stewart, John Edward

Ne users feel pulled to explore every option ("the possibilities are endless!", pp. 70 to 78), so they find it hard to reach conclusions or decide. They often seem open-minded, receptive, creative, curious, random, easily distracted and playful. They enjoy play with words, ideas, associations and quips. Their openness can unsettle NPs around other types, typically J types. A Vietnamese note adds that strong Ne tends to crave everything and tire of it quickly.

How Ne differs from Ni:

• Ne leans on ideas in circulation more than Ni does. Ne users track which thinkers and theories are in fashion, and they tend to drop names, citing books or theorists to back an argument.
• NPs also rely heavily on contrast and comparison.
• Ni goes deep rather than wide and sees structured hierarchies rather than webs, especially when paired with Te.
• Ne shares information. Ni collects it.
• Ne knows a little about a lot. Ni knows a lot about a little.
• Ne produces words easily. Ni struggles to put thoughts into words.

6.3Introverted sensing (Si)

Pages 79 to 85.

• Role: stores, condenses and recalls information, draws on past experience, routine and tradition, and registers sensations inside the body
• Most common in ISTJs and ISFJs, and also strong in ESTJs and ESFJs
• Shows up as routines and habits, valuing and preserving "the tried and true" (pp. 79 to 85), conservatism about material things, and high regard for tradition and authority
• Famous ISJs: Dick Cheney, Martin Luther, Mother Teresa, George H.W. Bush

Si cares most about the routine and familiar. It is cautious and conservative, and it builds on existing resources, beliefs and practices instead of seeking out new ones. ISJs take their responsibilities seriously, down to the last detail.

6.4Extraverted sensing (Se)

Pages 86 to 91.

• Role: reads external details and events and reacts to them quickly, hunts for a wide range of new sensory experience, and engages physically with the world
• Most common in ESTPs and ESFPs, and also strong in ISTPs and ISFPs
• Shows up as a hunger for sensation, bodily intelligence, a sharp eye for detail, a feel for style and appearance, hands-on activity, and performance that looks effortless
• Famous ESPs: George W. Bush, LeBron James, Beyoncé, Shakira, Donald Trump

How Se differs from Si:

• Se attends to details in the surroundings. Si recalls past details and reconciles them with the present.
• Se gathers concrete information widely and wants variety and novelty. Si takes in less and draws on past experience.
• Se types also care more about physical appearance.

6.5Introverted thinking (Ti)

Pages 92 to 97.

• Role: examines practical or conceptual problems with deep, implicit and finely graded logic, and builds and refines personal methods, strategies and concepts
• Most common in INTPs and ISTPs, and also strong in ENTPs and ESTPs
• Shows up as deep skepticism, tacit logic, self-regulation and self-improvement, and a strong need for independence and autonomy
• Famous ITPs: Einstein, Bill Gates, Henri Bergson, Robert Pirsig, Robert Nozick, Ken Wilber, Lance Armstrong

6.6Extraverted thinking (Te)

Pages 98 to 102. Practical Typing covers the pair in Thinking functions, Te and Ti.

• Role: states logical judgments concisely, and makes systems and operations more rational, efficient and effective
• Most common in ENTJs and ESTJs, and also strong in INTJs and ISTJs
• Shows up as explicit logic, precise and pointed speech, bureaucracy and red tape, and a taste for quantitative methods ("Show me the numbers!", pp. 98 to 102)
• Famous ETJs: Henry Ford, Bill O'Reilly

How Te differs from Ti:

• Ti users turn their thinking inward and organize their own thoughts and judgments.
• Te users turn thinking outward and decide on facts.

6.7Introverted feeling (Fi)

Pages 102 to 108.

• Role: explores and refines personal tastes, feelings and values, which builds a strong sense of individuality; keeps inner emotional and moral order; invests emotionally in a small number of people, animals or interests
• Most common in INFPs and ISFPs, and also strong in ENFPs and ESFPs
• Shows up as support for underdogs, emotional restraint, nuanced morals and values, nurturing and caregiving, and sensitivity to perceived unfairness and injustice
• Famous IFPs: Henry David Thoreau, Jean-Jacques Rousseau, Kierkegaard, Camus, Virginia Woolf, Van Gogh, Luke Skywalker, J.D. Salinger, Jane Austen, Bob Dylan

6.8Extraverted feeling (Fe)

Pages 109 to 114. Practical Typing covers the pair in Feeling functions, Fe and Fi.

• Role: surveys a wide range of human emotions, values and morals while working toward consensus between people or in a group; voices feelings and judgments directly; coaches and motivates others toward growth and excellence
• Most common in ENFJs and ESFJs, and also strong in INFJs and ISFJs
• Shows up as a focus on people, emotional expressiveness, communication skill, talkativeness, attunement to social norms and a habit of giving advice
• Famous EFJs: Dr. Martin Luther King, Dr. Phil McGraw, Frasier Crane (television)

How Fe differs from Fi:

• Fi users focus on their own inner feelings.
• Fe users focus on feelings in the outside world.

7Confirming a type

Pages 18 to 22.

Core steps:

• Understand the framework (the function stack)
• Take a test
• Reflect on yourself
• Discuss with others

Additional steps:

• Recall childhood memories
• Ask which types you are least like
• Ask which functions you use the least
• Watch for enantiodromia, the flip of something into its opposite
• Put inconsistencies in perspective
• Avoid over-focusing on particulars

8Four temperaments for team building

David Keirsey grouped the Myers-Briggs types into four temperaments. The temperaments are not arbitrary collections of traits. They come from the interaction of two basic dimensions of human behavior, communication and action, which is to say what we say and what we do.

• Communication: concrete (talk about reality) or abstract (talk about ideas)
• Action: cooperative (do what's right) or utilitarian (do what works)

9References

• Drenth, A.J. My True Type: Clarifying Your Personality Type, Preferences & Functions. Page ranges are cited in each section above.
• Personality Junkie. Typology 101.
• Personality Junkie. Functional stack and type dynamics theory.
• 16Personalities. Our theory and the 16 personality types.
• Practical Typing. Feeling functions, Fe and Fi, Thinking functions, Te and Ti, and 7 differences between Ne and Ni users.
• Very Well Mind. The Big Five personality dimensions, and Wikipedia, Big Five personality traits.
• Keirsey. Temperament overview.
• Wenger. Building Effective Teams Using the Myers-Briggs Personality Types.
• A video on cognitive functions, linked from the original note: YouTube.