INFJ vs INTP

There are many INFJs who have tested as INTP before discovering their type (including myself) and INTPs who have tested as INFJ. The two types are very different from a theoretical point of view because they belong to different temperaments (Rational INTP and Idealist INFJ) and have different attitudes towards the world (J and P). The two types share only two cognitive functions and it would seem like there is little reason for indecision between these types. If we base similarity on the common shared functions alone, the two types share only Ti and Fe. It seems more likely that an INFJ would mistype as ISTP (Ti Se Ni Fe) and INTP as ISFJ (Si Fe Ti Ne). But that is not usually the case, INFJ and INTP are more similar than they appear on the surface.

Here are the cognitive functions for these two types:

INFJ: Ni Fe Ti Se

INTP: Ti Ne Si Fe

The Similarities

Behavior

INFJs and INTPs can exhibit similar behaviors. As intuitive introverts (INxx), both types can detach from the external world and escape into their minds. They can also appear clumsy and may have poor physical coordination because their sensory functions are relatively weak. They may also display similar interests in intellectually stimulating topics such as philosophy, science, mathematics and may work in fields that require little interaction with their immediate physical environment.

The T/F Dichotomy

The third letter in the MBTI type determines if a person is a feeler or a thinker. The terms can be confusing because every person needs to think and feel inorder to function. There is a similar personality theory known as Socionics, that uses more descriptive terms to differentiate this dichotomy.

Feelers value ethics in decision making.

Thinkers place emphasis on logic in decision making.

The two cannot be mutually exclusive. A shallow understanding of Jungian typology has led to the following misconceptions:

• Thinkers have no feelings, Feelers can’t think
• Thinkers are bright, Feelers are dumb
• Thinkers are indifferent, Feelers are compassionate

These stereotypes are not true. One can be a compassionate Thinker and a logical Feeler. They are easily dismissed as one dives into the cognitive functions. INTPs who are drawn to people or altruistic causes may type themselves as INFJ and INFJs who have intellectual interests may type themselves as INTP on the basis of the T/F dichotomy.

The J/P Dichotomy

I have mentioned the reason behind the Judger/Perceiver dichotomy in previous posts. On the surface, it may appear that Js are more organized than Ps and Ps are more open-minded than Js. This may apply as a general rule for most types but it is more complex in the case of INTPs and INFJs. You can read about the difference between J and P in this article.

Most of the common J traits do not necessarily apply to INFJs. INFJs may not organize their physical environment, follow routines or manage their time as well as most Js. Ps are known for procrastination and being scatter-brained but INTPs can be very focused and determined when they are intrinsically motivated to accomplish a goal.

Thought Patterns

The dominant cognitive functions of the two types are similar. Both Ni and Ti are objective and concerned with systems. The objectivity of Ni stems from its universal nature and intolerance of biases in its pursuit of the truth. Ti strives for thought precision and logical coherence therefore it openly questions thought processes and doubts itself to reach a state of self-assurance and harmony.

In INFJs, Ni can manifest as understanding people and minds. The tertiary Ti is used to organize the insights provided by Ni into a logical structure for coherence.

In the case of INTPs, Ti creates a curiosity for knowing how things work. The dominant and tertiary functions can work together to synthesize an internal model of the world.

For this reason, the two types can become great thinkers and are found abundantly among philosophers.

Cognitive Function Development

The development of the tertiary (3rd) and inferior (4th) function takes place in early to mid-adulthood, during the period when most people discover their type.

The tertiary function can be thought of as a crutch the mind relies on to reinforce the most active dominant and auxiliary functions. If the person is in the process of developing this function, it can become the most conscious process as it uses most of the person’s psychic energy. INFJs in their late teens or twenties who are developing their tertiary function can become aware of Ti because it is a conscious linear process as opposed to their dominant Ni which may not be noticed because they naturally “swim” in it as fish swim in the sea. During this time, INFJs will find it easier to articulate their insights and communicate them in a logical manner. If coupled with self-discovery, this function may feel like it is the dominant because it gives Ni its voice and allows their previously unconscious mental processes to come to light. If the INFJ engages in intellectual pursuits such as Academia, his/her tertiary function will get the opportunity to flourish and may feel indistinguishable from Ni. Many INFJs mistype themselves as INxJ or INTP because they believe they are both feelers and thinkers.
However, the two functions are very different as I will demonstrate in the next section.

The inferior function, also known as the aspirational function is usually the weakest and least developed cognitive function. It can become a source of insecurity if the person is immersed in an environment that requires the great use of this function. People also tend to overestimate the strength of their inferior function because they spend much effort in using it and developing it. In the case of INTPs, the inferior function is Fe, which is concerned with appropriate social behavior and taking care of others’ feelings. Fe is important for initiating and maintaining social relationships and is very important from an early age. It is common for young INTPs to unintentionally offend others because they may not have insight into what is considered socially acceptable. This is usually learned through trial and error (Si) and observing behavioral patterns (Ne). Social life requires them to spend more effort than other types in developing their inferior function so their inferior function may appear “stronger” than the inferior function of other types. It is rare for INTPs to immerse in Fe as it conflicts with their dominant process so it it usually manifests unconsciously. Most INTPs learn to feign Fe and adjust to their social environments using their auxiliary function (Ne). INTPs may mistype as INFJs, if they have developed their inferior function (Fe).

The Differences

Cognitive Functions

Contrary to what the letters suggest, INFJs are dominant perceivers ([Pi) and INTPs are dominant judgers ([J]i).

As introverted perceivers, the internal world of INFJs is dynamic and ever-changing. In the INFJ, Ni is used for building complex systems that are universal. When Ni gathers external information, it molds itself with the new data to lead to greater understanding. INFJs are known for analyzing situations from multiple perspectives to get a clear perception of the situation at hand. They may disregard their personal beliefs and convictions to deal with pragmatic concerns in the external world. Ni provides an intuitive understanding of situations but it is usually a means to an end and not an end in itself.

INTPs can store an enormous amount of knowledge because they can easily archive and organize the information they perceive (Si) as they form their opinions using their internal set of logical principles. Ti creates a coherent internal model of the world as perceived via Ne, to help the INTP gain an understanding of the world.  INTPs expect new data to make sense before accepting it into their internal world. They usually strive to understand the inner workings of systems to gain a clear understanding of the world. INTPs pursue learning as an end in itself and may accumulate a large amount of information over a lifetime. They value their internal model more than its compatibility with established facts and they may dismiss new evidence to maintain internal harmony. A famous example of this Albert Einstein’s refusal to accept non-deterministic interpretations of Quantum Theory stating “I still do not believe that the statistical method of the Quantum Theory is the last word, but for the time being I am alone in my opinion.”

Precision vs Accuracy

INFJs can tolerate vagueness, ambiguity, logical paradoxes and incoherence because their dominant function is unconscious and not always subject to the restrictions of conscious thought. They can emerge with seemingly spontaneous insights but maybe unable to describe the thought processes that led to their convictions because of the irrational nature of intuition. They cannot easily form their opinions on non-urgent matters because they tend to view things from multiple perspectives, and it is not unusual for their opinions to change as they gather more data.  Arriving at the “one truth” is more important than maintaining a solid worldview. It is common to hear responses such as “Depends, Probably…” on questions of truth and falsehood.

INTPs value precision and clarity of thought above all else. Therefore, they may filter the information they perceive to make it compatible with their internal logic. The binary nature of their dominant function, Ti requires complete integration of new information before they accept an idea as valid.  They are usually aware of the reasoning behind their actions because Introverted Thinking (Ti) is a conscious function. They can also easily validate information against their internal logic and form quick judgments on arguments from other people. They are more definite in their responses and feel more comfortable making absolute claims, “X is true, Y is impossible”.

Convictions

INFJs have strong convictions about external matters (values, vision, goals..) based on their irrational perception (Ni) but may not be able to defend it using their tertiary thinking function (Ti). They are the most intuitive type and they trust their insights as they rely on them for most of their lives. They may be unwilling to reconsider their views because they value “intuitive sense” over logic. As a result, they may come across as stubborn and inflexible with their opinions. However, they may radically change their views if there is a change in their intuitive perception.

INTPs have a good understanding of how the world works and can easily discern patterns they observe. The external attitude of their perception function (Ne) makes them flexible and open to change with everyday matters. However, their internal logic is personal and they place heavy emphasis in keeping it coherent. They can have a personal attachment to their logic and may be hesitant to share their deepest convictions for fear of exposing it.  They have the ability to detach their emotions and analyze external situations from an “objective” perspective. However, their need for a consistency may lead to self-doubt if their assumptions are challenged by external evidence.

Interests

As I discussed in the INFJ vs INTJ article, INFJs and INTJs belong to different temperaments.

INFJs are Idealists and are concerned with the animate world of beings.

INTPs are Rationals and are interested in impersonal systems that are open to objective inquiry.

For this reason, INFJs are usually driven by a cause (Ni) or a need for change (Fe) when they tackle intellectual problems. They are goal-driven and usually pursue interests that will help them achieve their social goals. They are usually attracted to Art, Philosophy, Writing, Poetry, Social Sciences…

INTPs are driven by curiosity and a need to create an objective and consistent model of the world. They think for the sake of thinking, and pursue their interests to gain a clearer understanding of the world. Their interests can include the humanities, but they tend to be attracted to theoretical “hard sciences” such as Pure Mathematics, Engineering, Architecture, Computer Science…

Creativity

Both INFJs and INTPs can be very creative. INFJ creativity is symbolic and inspired by Introverted Intuition (Ni) where INTP creativity is synthetic and gathered through Extroverted Intuition (Ne).

INFJs can be gifted writers and poets because they can channel their insights (Ni) into aesthetic works of art (Fe). Their creative process is mostly unconscious and uses archetypes, abstractions and symbols.

INTPs can be excellent theorists, mathematicians, and intellectual revolutionaries because they have a broad imagination (Ne) and are able structure their perceptions into a logical form (Ti).  Their creative process requires effort and concentration and conscious manipulation of mental entities.

Perception of Time

INTPs and other xNPx types have a detached perception of time and tend to see the past-present-future as a continuum. They have a historical perspective and set their goals to accumulate memories and achievements that can be viewed from an autobiographical context.

INFJs and xNJx types have a future directed perception of time where the past and present are seen as contributing factors to a vision. They view time as a finite resource and strive to accomplish their goals to directly experience the success in the limited time they have.

Jungian Types and Perception of Time

Speech

INFJs are less verbose than INTPs and may struggle with expressing their ideas in words because their thought process is not always linguistic. They have the ability think in feelings, images, symbols, hunches… so it is hard for them to articulate the thought process that led to their conclusion. They can also make intuitive leaps between ideas and miss details in their arguments.

INTPs are very articulate and careful with their word selection. They can convey their thoughts in a clear fashion and are very good at explaining material to another person. They try to convince themselves as much as the other person when they are trying to get a point across. Their speech tends to be slower than Extroverted Thinkers but it is coherent and easy to follow.

Summary

	INFJ	INTP
Internal World	Dynamic	Static
Drive	Vision	Curiosity
Understanding	Intuitive	Logical
Goals	External World (Fe)	Internal World (Ti)
Creativity	Inspiration	Imagination
Speech	Terse	Elaborate and Verbose

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