MBTI Personality Test

I tend to get INTP in these tests pretty consistently. I usually enjoy the company of other NT types and one of my best friends is a very typical ENTJ. Last few years I've really developed those F functions a lot.

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I got really into MBTI a few years back and absorbed an insane amount of knowledge and insight on the topic in a short while. I typed this up back then, and since the topic came up I'd like to share it with you guys. Sorry for the wall of text, I'm on Mobil and formatting is a pain.

In order to understand the "dichotomies", you must first understand that the four-letter "type" is really just a shorthand indicating a person's development of four different cognitive functions, as described by Jung: Sensing, Intuition, Thinking and Feeling.
These functions are divided into opposing pairs that fulfill two different roles: Perceiving and Judging.
Sensing and Intuition are opposing perceptive functions. They describe how an individual takes in information from the world. Opposing in this case means that they share bandwidth, resulting in one being suppressed while the other is expressed.
Broadly, you can say that Sensing concerns the immediate sensory data entering conscious awareness and focuses on specific details, while Intuition concerns gaining an understanding of the bigger picture and capacity for abstraction, and focuses on alternate possibilities.
Yes, that sounds vague and AFAIK even Jung was vague on what Intuiton really means, other than it being related to subconscious processes.
Thinking and Feeling are opposing decision-making functions, also called Judging functions. They fulfill the role of making decisions and forming opinions, and they are responsible for pattern recognition and model-making in a broad sense. They differ in that Thinking is concerned with objective, impersonal decisions and universal truth: it is the rational logic machine of your mind. Feeling is all about personal concerns, be it your own personal emotions or values, or those of your peer group or even your enemies. If it is subjective, it is the domain of Feeling.
They are opposed the same manner as the perceptive functions; if one is expressed, the other one is suppressed.
Now, understand that Perception and Judgement really must work together; you can't have one without the other. Without Judgement, you would be hopelessly adrift in a sea of sensory input, unable to even discern objects, much like a baby. And without Perception, well, you wouldn't exist at all, seeing as your presence as an independent being in this world can only be inferred via sensory information. So, these functions work in tandem to create your unique worldview. Every individual makes use of these functions, either subconsciously or consciously. Your tendency to rely on one or more functions in different situations is what is going to determine the makeup of an individual's personality, and that tendency is going to be heavily influenced by how mature a function is, since well developed functions produce reliable results.
Development in this case means the degree to which you are consciously aware of the function expressing itself in your immediate experience, its level of maturity and your ability to discern appropriate utility of the function.
A well-developed function is one you are comfortably aware of, you know when and when not to rely on it, and you can choose to make active use of it as well as know how to enlist other functions to aid it.
For example: a mature logical reasoning capability is improved by the creativity granted by capacity for abstraction.
Really, the most important distinction between crude and developed functions is being consciously aware of their expression and being able to actively make use of them, rather than being unconsciously controlled by their passive expression.
The final piece of critical information regarding functions is that they can be applied in two different realms: your own internal processes, or the external world. This is what is meant by introversion and extraversion. Even opposing functions, like Thinking and Feeling, can be expressed simultaneously and even aid each other, so long as they are applied to different realms. If one is extraverted and the other is introverted, they no longer need to compete for expression (share bandwidth) and don't suppress each other.
With this distinction, the four functions Sensing, Intuition, Feeling and Thinking really become eight functions: Introverted Sensing, Extraverted Sensing, Introverted Intuition, Extraverted Intuition, and so on...
I'm sure you can figure out what kind of tasks most of the functions are suited for, but here's an example: Extraverted sensing concerns the ability to take in details from the environment and recognize opportunities for immediate action, as well as being focused on the present moment. This function is heavily involved in crafts or when playing games or sports.
The Introverted Sensing however, is not about the present moment. It is utilized when recalling images, words, symbols and so on. I suppose visualization and any kind of recreation of sensory data in your mind is also the domain of Introverted sensing.
So, in the end, how does an individual's development and reliance on different cognitive functions get translated into a "type"? Keep in mind one very important thing: it's all about the order of preference of your functions.
Having developed one function, it is likely, but not necessary, that the opposing function has been neglected. It is definitely possible, and common in mature individuals, that both Thinking and Feeling are well developed. Or that both the extroverted and introverted expressions of a function are well developed. Basically it boils down to simplification, and a bit of shoehorning to fit the pattern of opposing functions.
The simplification is (let's take the Feeling function as an example): if your Extraverted Feeling function is more developed than your Introverted Feeling function, even slightly, then the Feeling function is considered Extraverted. It might be a small difference, but the line must be drawn somewhere.
So, one of your functions is going to be the most developed and reliable of them all, and as such you'll likely have formed a preference for using it a lot. This is what is called your Dominant function. If the Dominant function is Introverted, you're an introvert (so your MBTI type starts with an I); if it is extraverted, you're an extrovert (MBTI first letter: E). But remember how you can't function with just one type of function, you need both Perception and Judging? So, if your Dominant function is either Sensing or Intuition (Perceptive functions), then it will need to be backed up by either Feeling or Thinking (Judging functions). This is called your Auxillary function, and according to the MBTI pattern, if your Dominant is Introverted, then the Auxillary is going to be extroverted, and vice versa.
There is more to the MBTI than Dominant and Auxillary, however. Remembering how opposing functions work, it follows that since one function is favored as Dominant and actively developed, its opposite is likely to be suppressed and underdeveloped. This is called the Inferior function, and it is always the mirror image of the Dominant.
For example, if the Dominant is Introverted Sensing, the Inferior will be Extraverted Intuition. This example is describing a proficiency with remembering details and a preference for evaluating situations based on comparison with earlier similar experience, but a deficiency in being able to connect-the-dots.
Finally, the last of the four functions that isn't Dominant, Auxillary, or Inferior is simply called Tertiary (third), denoting that it isn't as actively suppressed as the Inferior, but still likely less developed than the first two. The Tertiary function is the mirror image of the Auxillary (same purpose, but opposing functions and opposing I/E valence).
So, in our example:
Dominant: Si (Introverted Sensing)
Auxillary: Te (Extraverted Thinking)
Tertiary: Fi (Introverted Feeling)
Inferior: Ne (Extraverted Intuition)
Now, this is really all the information you need to be able to tell what mode of cognition a person is likely using most of the time, as well as their likely weaknesses in cognition, and it is what is reflected by the four-letter MBTI Type Indicator.
In our example, this type is called an ISFJ: Introverted perceptive dominant, Sensory Feeler, and the extroverted auxillary is a Judging function.
The first letter (I/E) tells you whether that type's Dominant function is introverted or extraverted, and by extension, that the Auxillary is the opposite orientation.
The second pair (S/N) tells you whether that personality type gathers information primarily with Sensing or Intuition.
The third letter (T/F) tells the preference of the decision-making and opinion-forming function.
So wait, what about that J/P dichotomy? Well, this is about a person's way of interacting with the external world, in other words, the orientation of their extroverted function (In Extroverts, it is the Dominant, and in Introverts, it is the Auxillary). It tells you whether the Extroverted function is a Perceptive or a Judging function. So, a person whose Dominant function is Extroverted Feeling, is going to be of the Judging variety, hence prone to making decisions and moving on.
If a person has a Perceptive mode of extraverting themselves however, that extraversion is going to be much more focused on gathering information, getting a good overview of the available options, even hesitating to make decisions or form opinions until pressed to do so.
One can look at it like this: a Judging character is much more likely to want to impress upon the external world an extension of their own internal world, or impose their will on others, while a Percieving type is more likely to want to gain an accurate reflection of the external world inside their own minds, and will hesitate to bring their internal world out into the open lest they influence the very thing they are trying to clearly percieve. They will likely resist someone trying to impose their will on them.