Guide to self-typing: the basics

Why online tests are not enough to figure out which type you really are

Part 1: MBTI theory debunking stereotypes

How many of you started with 16personalities, attracted by the concepts and the curiosity to discover more about yourselves? We did it too.
INFJ got his real type since the beginning – confirming it only after a thorough analysis – while ISTJ got mistyped as INTJ. Not only once, and not only with this test: many online tests gave him the same result, until one day, when he started reading more about cognitive functions and discovered he was actually ISTJ.
The point is: there is a huge intuitive bias in the community; so, if you're one of the few “real” intuitives you're less likely to be mistyped. But there are way too many INxJs out there, and a huge percentage of them are mistyped.
Many of us are (or have been) in the same situation, and we are here to explain why online test results are inaccurate. Hope you’ll find it useful!

Online "MBTI" tests: pros and cons


  • They are a good starting point, they can give you a clue after all
  • They are quick and easy, and can raise your interest for the subject
  • Each personality has a detailed (and quite accurate) profile, with tips for growth and development that everyone can find useful


  • They are NOT based on MBTI theory, they just use the same definitions
  • They don't consider your cognitive functions, but only the axis E/I, J/P…
  • Some questions are tricky and susceptible to the individual's interpretation

Extroversion vs. Introversion – E/I axis

According to stereotypes, introverted types are loners or nerds who don’t like interacting with people, always locked in their room, and extroverts are flamboyant party animals and/or bossy micromanagers. No in between.
Online tests follow the same logic: if you’re shy, reserved, or value alone time, you will favor the introverted axis; if you love spending time with friends or talking with people, you’re an extrovert.
While this can be true in some cases, it’s not the most efficient way to type someone. There are a lot of introverts who like hanging out with friends every week and a lot of extroverts who are fine with spending a Saturday evening at home, watching Netflix or reading a book.

According to the MBTI theory, extroverted types have a dominant extroverted function and prefer to direct their energy outwardly. For example, Te-doms (ExTJs) are usually concerned with organization in the environment and leadership, while Ne-doms (ENxPs) are good at finding abstract possibilities/points of view in the outer world, etc.

Introverted types’ main function is instead focused on their inner world of values, impressions and perception, and counterbalanced by an extroverted function that regulates their way of interacting with the outer world. For example, INxJs have dominant Ni – one of the most misunderstood functions ever – and auxiliary Te or Fe, while ISxPs lead with Ti or Fi and have auxiliary Se, which helps them collecting sensory experiences “in the moment” and being very aware of the physical world.

Sensing vs. iNtuition – S/N axis

Here we are, the intuitive bias haunting the community!
Every online test out there agrees with the statement: intuitives (both xNxJs and xNxPs) are special children gifted with the power of imagination, SJs are boring clerks who schedule every minute of their lives and SPs are impulsive adventurers living on the edge.
Do you like talking abstract topics, art and philosophy? Then you MUST be an intuitive!
Do you prefer staying practical and favor everyday necessities over fantasies? Ahh, you boring sensor.
The reality is, both intuitives and sensors have sensing and intuition. Both can be practical (Te-users, for example) or imaginative; it really depends on how you use your N and S functions and how they interact with each other (remember that Si always couples with Ne and Ni with Se: Si collects elements from one’s personal experience and Ne transforms them in something new/different/unknown, while Se gives concrete shape to Ni’s impressions).
According to Myers-Briggs, the difference between intuitives and sensors is determined by which function is higher in your stack. If you have dominant or auxiliary intuition (Ni or Ne), you’ll get an N; if you have dominant or auxiliary sensing (Si or Se), you’re a sensor.

Thinking vs Feeling – T/F axis

In the community, thinkers are usually depicted as cold, unfeeling robots who don’t really care about emotions, while feelers are cheap improvised psychologists, who can read everyone (especially xxFJs) or moody crybabies with artistic whims (xxFPs).
Well, that’s not true either. MBTI theory classifies as thinkers those who have a thinking function as dominant or auxiliary (Ti for xxTPs, Te for xxTJs) and as feelers those who prefer a feeling function (Fi for xxFPs, Fe for xxFJs). While it’s true that thinkers favor logic over emotion, for example, this does not mean they can’t make decisions based on their values or the well-being of others, if they believe it’s the most logical and/or efficient choice (remember that Te always combines with Fi, and Fe with Ti; F and T functions are not mutually exclusive). Likewise, feeling types can sometimes come across as thinkers when they display strong will and efficiency while making decisions “for the greater good”: their ability to combine humanitarian intentions with impersonal logic makes them great diplomats.

Judging vs. Perceiving – J/P axis

How many of you know the first three letters of their type but are unsure between J and P?
Maybe a lot. But that’s not possibile in MBTI, because the difference between J and P is… the whole functional stack.
For example, ENFJ is FeNiSeTi and ENFP is NeFiTeSi. They share three letters, but ZERO cognitive functions.
The theory is simple: perceiving functions are intuition and sensing, while thinking and feeling are judging functions. Both can be introverted (Ni, Si, Fi and Ti) or extroverted (Ne, Se, Fe and Te).
Always consider the first two functions in your stack: xxxPs extrovert a perceiving function (Ne or Se) and judge internally (Ti or Fi), while xxxJs combine extroverted judging (Te, Fe) with introverted perceiving (Ni, Si). The whole stack is composed by a combination of two judging and two perceiving functions with inverted focus: if the first one is introverted, the other will be extroverted.

While it’s true that perceivers are generally more flexible and spontaneous – that’s because they extrovert a perceiving function – and judgers tend to be more organized because their judging is focused outwardly, the reality is much more nuanced than it appears.


  • Every type has both E and I, S and N, F and T, P and J functions interacting with each other
  • The letters of your type are influenced by the first two functions in your stack
  • Behavior is not a good way of typing someone
  • Typology is concerned with how you collect and sort out information, how you deal with your inner and outer world, how you interact with your environment, and many other factors that we will analyze in the next posts
  • Personality” is not a box. It’s how you use your brain that defines you, and not how you view yourself.

That’s why it’s important to know the basics and the logic behind MBTI theory, rather than limiting yourselves to online tests and descriptions.