The INTP personality type makes up about 3-4% of the general population. INTPs’ dominant function is Introverted Thinking (Ti), which can be associated with high levels of focus, self-discipline, intentionality, independence, and intensity of thought. Such are the INTP’s signature strengths.
Although INTPs may not discover their intellectual side (i.e., their N) as early as INTJs do, once their auxiliary Ne is fully awakened, they take intellectual matters very seriously. They work to discern unifying themes and metaphysical truths that explain the underlying nature of things. Especially early in their intellectual journey, they feel they must develop a sufficient understanding of the whole before they can competently assess any of its constituent parts. Toward this end, INTPs may devour stacks of books on subjects like philosophy, religion, psychology, and evolutionary theory.
When vacationing from their personal projects and investigations, INTPs, like ENTPs, can be quirky, witty, and engaging. Since they extravert Intuition (Ne) and Feeling (Fe), they can have a certain charm, approachability, and congeniality about them. When discussing a topic that interests them, they can be stimulating conversationalists, as their ever active minds can easily connect one topic to another, paving the way for a multifaceted and broad-ranging dialogue. If disinterested however, such as when forced to endure protracted small talk, they will quickly zone out or find a way of redirecting the conversation. Despite appearing outwardly genuine and personable, INTPs are more interested in discussing ideas than the commonplace details of people’s lives. They enjoy discovering what makes people tick—their motivations, interests, patterns, and propensities. This allows INTPs to further hone and refine their theories (Ti-Ne) of human nature (Fe).

Bill Gates, INTP
Like other introverts, INTPs can be anxious and self-conscious characters. It is not uncommon for them to display a handful of nervous habits, or at least some sign that they are not at ease. They generally avoid direct eye contact, as though the gaze of their interlocutor may somehow harm them or render them incapable of thinking or communicating. INTPs often have enough insecurity about the discombobulated nature of their Ne expressions in the first place. Feeling that someone else is watching or critiquing them only makes it worse.Like INFPs, INTPs can be slow to disclose the contents of their inner world. As strange as it may seem to other types, INTPs often conceal some of their most dominant personality features, namely, their highly cerebral, rational side. It may only be a select few who are granted full access to this side of the INTP. Others may only encounter INTPs’ inner world through encounters with their work, such as by reading something they have written. This may explain why many INTPs often take interest in writing, which provides an excellent forum for expressing themselves more fully and precisely.
Because of their reluctance to freely display the rational dimension of their personality, as well as the scattered nature of their Ne expressions, INTPs often feel their true level of knowledge and competence goes unnoticed by others. This is especially common in the workplace, where their lack of enthusiasm for organizational life, combined with their quirky outward demeanor, may be mistaken for incompetence.
INTPs’ Functional Stack & Type Development
INTPs’ functional stack is composed of the following functions:
Dominant: Introverted Thinking (Ti)
Auxiliary: Extraverted Intuition (Ne)
Tertiary: Introverted Sensing (Si)
Inferior: Extraverted Feeling (Fe)
INTPs’ personality type development can be broadly conceived as consisting of three phases:
Phase I (Childhood-20s)
This phase is characterized by the emergence and differentiation of INTPs’ dominant function, Introverted Thinking (Ti). Early in life, INTPs often employ their Ti to focus on one or two pursuits. They may, for instance, use it to master video games, program computers, get good grades, or perfect their 5 K time. Since Ti is a Judging function, INTPs tend to take themselves and their lives quite seriously. Even from a relatively young age, they are self-disciplined and goal-oriented, striving for excellence in whatever captures their interests.
While often described as pure skeptics, this is not characteristic of many Phase I INTPs. While INTPs are naturally logical thinkers, they, like ISTPs, are not born skeptics. INTPs start with a given (T), and if clearly not unreasonable, will assume it true unless their Ne or Si suggest otherwise (functions which in this phase are not well developed). INTJs, by contrast, whose first function is Intuition (Ni), do not start with a given, but approach things more openly, through the eyes of perception. They use their Intuition to discern whether or not something seems viable. Consequently, INTJs are often ahead of INTPs, as well as most other types, when it comes to formulating their own personalized worldview.
Phase II (Late teens-30s)
Once their dominant Ti reaches a certain level of consciousness and differentiation, INTPs’ inferior function, Extraverted Feeling (Fe), enters the picture and begins to play a more influential role. INTPs are not immune from the dominant-inferior wrestlings described in our Introduction, making this phase as challenging for them as it is for other types.
Phase II INTPs also show increasing use and development of their auxiliary function, Extraverted Intuition (this can also begin in Phase I for some INTPs). During this phase, INTPs often develop a stronger interest in intellectual and philosophical endeavors, poised to see and understand “the big picture.” They also become more skeptical toward certain Ti conclusions they made in Phase I. Developing their Ne involves an opening of prior judgments to allow an influx of new information. But since Ne is extraverted and expansive, INTPs must explore a breadth of ideas before they feel confident about who they are and what they believe. Thus, Phase II INTPs may find it much easier to identify what they don’t believe than what they do believe. Many will struggle with nihilism and relativism, worried that they may never find absolute truth. It can therefore take INTPs a great deal of time, even well into their thirties, to discern what they believe about the world and about themselves, let alone figure out what they should be doing. Unfortunately, societal pressures and expectations often push Phase II INTPs (as well as other types) into relationships or careers well before they are ready.
Phase II INTPs may also begin to tap into their tertiary function, Introverted Sensing (Si). They use their Si to recall past experiences and acquired wisdom. This prevents them from having to retread paths they have already explored in the past.
Phase III (30s, 40s, & Beyond)
If all goes well and they are fortunate enough to enter Phase III, INTPs become increasingly aware of the insidious ways of their inferior Fe. As they become more aware of their inferior and learn to function more authentically as INTPs, they experience greater balance between their Ti and Fe. They learn that integrating their Fe happens naturally and indirectly as they go about authentically using their Ti, Ne, and Si. As they cultivate conditions that support their natural strengths, Phase III INTPs come to experience a heightened sense of peace, wholeness, and satisfaction. (This Personality Junkie type profile is continued on the next page.)


Holy shit, this makes so much sense. Thanks!
Best,
Koen
This is a very insightful result for me. Things that I didn’t think would be picked up, such as eye contact, was spot on. Things like my cognitive learning seemed to be sparked by somethings and not other, which made me pay attention to this statement “Especially early in their intellectual journey, they feel they must develop a sufficient understanding of the whole before they can competently assess any of its constituent parts.” I plan to ensue more about INTP’s for my own sake.