By Dr. A.J. Drenth
“ISTP” is one of sixteen personality types. While some estimates suggest ISTPs comprise only 5% of the general population, my research and experience suggests this type to be more common, perhaps even as high as 8%. Male ISTPs are thought to outnumber ISTP females at a clip of three to one.
Like the INTP, the ISTP’s dominant function is Introverted Thinking (Ti), which can be associated with high levels of focus, self-discipline, intentionality, independence, and intensity of thought. ISTPs take life rather seriously and use their inner logic to discern the best ways of navigating it. They may, for instance, use Ti to work out their own personal methods for maximizing performance in a particular sport. They love using their Ti to solve practical problems or to optimize functioning. Because of their independence, self-directedness, and competitiveness, ISTPs may excel at nearly anything they set their mind to.
Because ISTPs’ Thinking is introverted in its direction (Ti), it often goes unnoticed by outsiders. What others tend to see is ISTPs’ engaging in action (Se) or mixing with people (Fe). ISTPs’ Extraverted Feeling (Fe) can bring a surprising amount of affability and personableness to their outward presentation. ISTPs often present as sincere, genuine, and approachable. Their Fe confers a certain childlike innocence that others may find refreshing.
Since neither Ti nor Se is a highly verbal function, ISTPs can be persons of few words. Their relationships are often built around shared interests or activities rather than extensive conversation. But since status and reputation are important to their Se and Fe, ISTPs may be far more talkative at work or in public settings than they are at home. In public, they may be fun and outgoing. In private, they may seem more aloof or disengaged, sensing that their intimates cannot provide them the same degree of ego boost they find in the public arena (Fe). This ostensible disparity between their private and public persona may lead their intimates to consider them narcissistic or hypocritical.
ISTPs commonly display conventional, sometimes stylish, forms of dress. While their Ti is concerned with functionality and practicality, their Se and Fe are attuned to the trendy and popular. Physically, ISTPs may have either a lanky or muscular build. While athletic engagement often keeps them fit throughout their childhood, their love for food (Se) may lead to problems with weight in adulthood.
While not to the same extent as their ESTP counterparts, ISTPs are undeterred from investing in high quality and/or high-status goods. Like other Se types, they can appreciate excellent food (some are even foodies) and stylish clothing. Fancy or vintage sports cars, motorcycles, or power tools commonly line the garages of ISTPs.
Like other SP types, ISTPs often display great kinesthetic intelligence. They are often mechanically-inclined and endowed with excellent hand-eye coordination. In contrast to INTPs, who sport high levels of mental energy, ISTPs may exhibit higher levels of physical energy and stamina. While INTPs use their Ne to explore ideas, the ISTP and ISFP prefer using their hands, body, and other senses to explore and manipulate the concrete world (Se).
Because of their preference for hands-on activities, ISTPs may underperform in academic settings. This is typically not due to a lack of ability per se, but a lack of interest or stimulation. As is true for all Sensing types, being forced to deal in abstractions for too long can be draining for ISTPs. Their need for physical activity and impatience with abstractions may also explain why ISTP school children are more likely to be diagnosed with ADD or ADHD than some of the other personality types. ISTP students who can set their focus on a particular career goal or endpoint, such as becoming a surgeon, are apt to fare better.
Generally speaking, ISTP career-seekers are wise to pursue careers that allow them to use their practical intelligence to solve concrete problems (i.e., Holland “Realistic” careers). They can make excellent artisans, athletes, mechanics, drummers, maintenance workers, chiropractors, surgeons, pilots, chefs, etc.
While ISTP differ from ISTJs by only one “preference” (i.e., J-P), these types actually share zero functions in common. This makes them far more different than is sometimes recognized. As TJ types, ISTJs are more direct and firm (even blunt) in their assertions than ISTPs are. ISTPs use Fe rather than Te, which confers a certain social ease, even charm, which ISTJs often lack. Moreover, ISTPs use Se rather than Si, making them less concerned with preserving past precedent than ISTJs are. Finally, ISTPs are more inclined toward “hands-on” and Realistic careers, whereas ISTJs gravitate toward “white collar” sorts of work.
ISTP Personality Type Development & “Functional Stack”
ISTPs’ functional stack is composed of the following functions:
ISTPs’ 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 ISTPs’ dominant function, Introverted Thinking (Ti). Early in life, ISTPs often use their Ti to focus on one or two pursuits. They may for instance, funnel their Ti energies into mastering video games, tinkering with computers, or learning the best way of shooting a basketball. Since they often apply their Ti to hands-on activities—sports, Legos, drumming, video games, and the like—Phase I ISTPs may also show significant development of their auxiliary function, Extraverted Sensing (Se).
Since their Ti is a rational Judging function, ISTPs tend to approach life fairly seriously. Even from a relatively young age, they can be self-disciplined and goal-oriented, striving for excellence in whatever they do. They can differ markedly from ESTPs in this regard, whose dominant function (Se) is a Perceiving function, leading Phase I ESTPs to be more open-ended and easygoing. While both types utilize Se and Ti, ESTPs are more concerned with perceiving or experiencing the outside world (Se), while ISTPs are more intentional, focused, and self-directed (Ti).
Phase II (Late Teens-30s)
Once their dominant Ti reaches a certain threshold of strength and dominance, ISTPs’ inferior function, Extraverted Feeling (Fe), enters the picture and begins to play a more influential role. This can be confusing because Fe is not next in line in their functional stack. Its undue influence can be understood as deriving from its bipolar relationship with ISTPs’ dominant Ti.
Phase II ISTPs also show increasing use and development of their auxiliary function, Extraverted Sensing (Se). This may involve exploring new hobbies and interests, such as gourmet cooking. As a Perceiving function, Se also leads to an opening of their Ti judgments to see if they pass the test of lived experience. Since Se is an extraverted and expansive function, Phase II ISTPs may feel it necessary to explore a wide range of experiences before arriving at confident conclusions.
Phase II ISTPs may also begin to tap into their tertiary function, Introverted Intuition (Ni), which can subconsciously assist ISTPs in piecing together their Se experiences, further clarifying their identity and worldview.
Phase III (30s, 40s, & Beyond)
If all goes well and they are fortunate enough to enter Phase III, ISTPs 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 ISTPs, they can experience greater balance between their Ti and Fe. This will be elaborated later in this profile.
ISTPs’ Dominant Function: Introverted Thinking (Ti)
To understand ISTPs, or other IP types, it is necessary to recognize the full implications of their dominant function being a Judging function. I discuss this issue in my post, Rethinking Judging and Perceiving in IPs & IJs. In short, I suggest that ISTPs are best viewed as predominant Judgers and display many characteristics of EJs, only that these behaviors are directed inwardly or toward themselves.
Ti involves the use of logic and reason for the sake of understanding a given problem, situation, or system. ISTPs use Ti to solve problems, to optimize functioning, and to bring structure and order to their inner world. This inner structuring grants them a strong sense of inner control. It allows ISTPs to be inwardly self-disciplined and to independently manage their lives and personal projects.
The disciplined nature of Ti may inspire ISTPs to frame their lives in terms of personal challenges or a series of independent projects. While not shying away from competing with others, ISTPs enjoy taking on challenges and projects for the mere pleasure of it. Such challenges may be physical (e.g., trying to achieve an optimal level of fitness), practical (e.g., fixing a car), creative (e.g., craftsmanship), or interpersonal.
At times, the inwardly focused and intentional nature of Ti lead can lead ISTPs to mistype themselves as ISTJs. In so doing, they rightly recognize their inner Judging nature, but wrongly conclude that they must be a J-type. They fail to recognize that the J-P label refers only to outward demeanor and behavior. This may partly explain what I see as the underrepresentation of ISTPs in demographic data.
Ti might also be viewed in terms of fluid intelligence, whereas Extraverted Thinking (Te) seems more related to crystallized intelligence. Ti is more intuitive, contextual, and right-brained, whereas Te is more procedure-oriented and left-brained. The fluid nature of their Ti, combined with the keen observational powers of their Se, contributes to ISTPs’ acumen as practical problem solvers. ISTPs can analyze a situation, discern how things should work, and then determine how to fix it. While a Te type might feel compelled to use schematics or manuals to diagnose the problem, ISTPs rely on their Ti’s ability to reason their way through concrete problems, even those they’ve never encountered. This contributes to their skill as mechanics, maintenance workers, machinists, surgeons, technicians, etc.
ISTPs’ Auxiliary Function: Extraverted Sensing (Se)
Introverted Sensing (Si) is conservative with respect to new sensations and the material world. Extraverted Sensing (Se), by contrast, is more materially liberal and novelty-oriented. Se types (especially ESPs) often exhibit a laissez-faire, “eat, drink, and be merry” approach to life.
Unlike Si, Se is not content with routine and familiar experiences. For this reason, ISTPs enjoy physical thrills and new sensations. Their Ti penchant for challenges, combined with the physically active and explorative nature of their Se, makes ISTPs solid candidates for sports and physical challenges. While their inferior Fe may like the camaraderie associated with team sports, ISTPs may also enjoy the individual challenge of activities like cycling or long-distance running.
Se also attunes to the concrete details and sensory information of the environment by way of the five senses. SP types scan the environment for interesting sensory novelties, noticing details in the environment that other types might readily gloss over. This is why SPs (especially ESPs) often have strong visual recall, or what is sometimes dubbed a “photographic” memory. ISTPs may utilize their Se’s attention to detail in any number of ways.
One of my ISTP friends, for instance, enjoys scavenging fields for arrowheads. As he saunters about, his Se scans the environment in hopes of finding another lost treasure. After locating an arrowhead, he further enlists his Se to explore its shape, texture, and other features.
ISTPs also employ their Se in their daily work as mechanics, technicians, chefs, construction workers, etc. They make excellent craftsmen, using their Se to attend to the finest physical details. They love working with their hands and using tools to produce high quality pieces.
Unlike the Ne-Si function pair, which encourages makeshift tool use (Ne) in the name of material conservation (Si), the Se-Ni function pair impels ISTPs to acquire the right tools in order to do the job the “right way.” In this vein, ISTPs are not opposed to spending a little extra on high quality tools, parts, etc.
Se also differs from Ne in that it is not a highly verbal or abstract function. So while INTPs enjoy sitting around discussing ideas, ISTPs would often prefer to be “doing” something. Even watching sports can be more stimulating than conversation for ISTPs, since it stimulates their Se and allows them to vicariously participate in the action.
ISTPs’ Tertiary Function: Introverted Intuition (Ni)
ISTPs’ tertiary function is Introverted Intuition (Ni). In combination with their dominant Ti, ISTPs may display some degree of interest in abstract or theoretical topics. After all, Ni and Ti are the same two introverted functions employed by INFJs, who are among the most theoretical-minded of all types. However, because ISTPs’ Ni is more unconscious, it is less accessible to them for immediate intuitive perception. Therefore, like other SP types, ISTPs are more likely to gain insight through analyzing a breadth of life experiences (Ti-Se). Ni can also aid in the process, helping ISTPs synthesize and extract meaning from a breadth of Se experiences.
ISTPs’ Inferior Function: Extraverted Feeling (Fe)
For those unfamiliar with the workings and powerful influence of the inferior function, as well as strategies for dealing with it, I encourage you to explore some of my posts on the inferior function. Like other types, ISTPs can be easily blinded to the degree to which their inferior function impacts their decisions and behavior. Without sufficiently understanding the inferior function, Extraverted Feeling (Fe), ISTPs will continue to feel incomplete and be prone to unhealthy decision-making in their careers, lifestyle, and relationships.
The ISTP’s personality type dynamics can be largely understood as an attempt find a balance between Ti and Fe, independence (Ti) and interdependence (Fe), self (Ti) and others (Fe). Since Ti and Fe comprise a functional whole, ISTPs intuitively realize that they need to better integrate their Fe in order to feel more whole and complete.
“In the grip” of the inferior function, all personality types are prone to acting compulsively and obsessively. Grip experiences can be difficult to escape, since the less conscious self (i.e., the inferior function) takes over as the driver of the personality. While the content of grip experiences may differ across the types, their basic shape is essentially the same.
For ISTPs (and INTPs), being in the grip often involves workaholism. As T dominants, work (including personal projects and hobbies), comprises a central component of ISTPs’ identity. In doing what they enjoy, ISTPs are naturally very disciplined and thorough. When they are in the grip, however, they become obsessive, perfectionistic, and unable to let go of whatever they are doing. During such times, ISTPs may alienate themselves from others, insisting they need more and more time to themselves (this is why ISTPs often test as Enneagram Fives). They become trapped, functioning only in Judging mode (Ti-Fe), while forgoing the Perceiving functions (Se-Ni) in the middle of their functional stack.
As for all types, the process of slipping into grip experiences is often subtle and insidious. For instance, ISTPs may have a goal in mind for what they want to accomplish that day, only to discover the task much larger than they originally imagined. But because a bigger task poses a greater challenge, they take the bait and see if they can still manage to get it done. The problem, of course, is that this essentially locks them into Judging mode, since any deviation into Se Perceiving will preclude them from accomplishing their goal. This includes closing themselves off to other people, who come to be viewed as intrusions or impediments to their productivity. Consequently, ISTPs who are frequently in the grip may end up ostracizing themselves from other people.
What is interesting is that ISTPs, like other types, can be relatively unaware of falling into a grip experience, rationalizing their obsessiveness as being “efficient” or “productive.” Moreover, since grip experiences are fueled by adrenaline, they can feel “good” at some level, allowing for heightened focus and endurance. At the same time, there is a part of ISTPs that knows they are in trouble. When all they can do is compulsively hurl themselves into their work, a part of them realizes this is unsustainable, unbalanced, and potentially destructive.
To compensate for the isolation involved with grip behavior, ISTPs may “crutch” their inferior Fe through their relationships, which provides the reassurance that external Fe support is available should they need it. This is why so many ISTPs (and INTPs) struggle when it comes to balancing their work and interpersonal relationships.
Slippery & Elusive Emotions
For ISTPs and INTPs alike, their Fe is rather naive and childlike. They may be easily moved by cheesy romantic comedies or sappy love songs, anything that incites their subconscious Fe emotions. They can also be easy targets for “love at first sight” sorts of infatuation. They may be particularly susceptible to being wooed by Feeling types (especially FJs), who can bypass their typical channels of logic and appeal directly to ISTPs’ less conscious Fe.
Because of the inferior position of their Fe, ISTPs struggle to intentionally contact or understand their emotions. It’s not they never experience emotions, but only that their emotions seem to have a mind of their own, coming and going as they please. So even if ISTPs are aware of what emotions are appropriate for a given situation, they often do not “feel” them at the time, engendering a sense of awkwardness or discomfort in emotional situations. They may even experience the desired emotion a few hours later, but it’s almost as though their emotions get “stage fright” when “put on the spot.” To compensate, ISTPs may try to use their Fe to offer the socially-appropriate words. But without experiencing the emotions directly, they often sound clumsy or contrived in their expressions. At times, this can be difficult for their romantic partners, particularly for FJ types, who desire a reciprocation of authentic emotional expression. But because of their Fe stage fright, ISTPs may not experience their feelings “at the right times” or can have trouble expressing them when they are present.
While ISTPs can certainly have trouble contacting their emotions, they usually have little difficulty overriding or detaching from them. Consequently, ISTPs are less apt to struggle with guilt, regret, or shame in the way that other types might. Others may even be surprised how quickly ISTPs can resume “business as usual” after what most would consider tragic or traumatic circumstances. This should not necessarily be viewed as a flaw in the ISTP, however, but merely a reflection of the unconscious nature of their Fe.
Conflict-Avoidance, Passive-Aggressiveness, & Desire for Affirmation
ISTPs’ want everyone to feel included and to be treated with fairness and respect (Fe). While not as warm or effusive as FJ types, ISTPs are concerned with others’ feelings and try to avoid hurting or offending them. Like FJ types, they seek to maintain a basic level of harmony in their immediate circumstances.
Fe also contributes to ISTPs’ desire for public affirmation. Fe involves making connections between one’s own emotions and those of others. While ISTPs may not always “feel” what others are feeling, their Fe still desires the sense of social affirmation and validation. Consequently, there are times when ISTPs are helpful or compliant largely for the sake of external approval or to maintain a certain public perception. ISTPs with a strong concern for their image can take social engagements quite seriously. They want others to see them as laudable employees, spouses, parents, or citizens. Their desire for public esteem can also be a motivating force in ISTPs’ desire for achievement (This is why ISTPs may also score high as Enneagram Threes).
ISTPs’ propensity for conflict-avoidance and need for affirmation, on the one hand, with their need for independence (Ti), on the other, contributes to no small number of relational difficulties. Especially when in the grip of workaholism, ISTPs may feel they don’t need or want other people around. Eventually, they come to a point of feeling miserably imbalanced, which prompts them to reinitiate contact with others, at least until they fall into the grip again. This cycle of alternating between needing and devaluing others is common among ISTPs and narcissists alike.
In the name of conflict-avoidance and preservation of external harmony, ISTPs may do all they can to circumvent directly expressing their frustrations or grievances. Wittingly or not, they view conflict as a potential threat to the relationship they depend on to meet their Fe needs, as well as a threat to the flawless image they seek to preserve. So rather than giving voice (Fe) to their concerns, ISTPs are more apt to analyze (Ti) or act on them (Se), often in passive-aggressive ways. They may, for instance, intentionally start spending more time at the office as a passive form of rebellion against their partner. Or, they may make sudden executive decisions without giving others any say or prior notice. Poor communication can also lead ISTPs to create a convoluted set of assumptions about what their partners think, want, and expect. Unhealthy ISTPs may spin an ever-expanding web of faulty beliefs and assumptions about their partner. In so doing, they often come to resent or otherwise think negatively of their mates, even if largely a product of their own faulty conclusions.
Personal Growth for ISTPs
Personal growth for ISTPs involves integrating their Fe through consistent and satisfying use of their Ti and Se. Integrating ISTPs must also must learn to recognize the difference between healthy modes of work versus functioning in the grip of their inferior function. Healthy work for ISTPs includes remaining open to Se experiences and diversions, which can keep them from becoming too one-track minded.
In addition to taking a healthier approach to their work, integrating ISTPs must enhance their self-awareness and communication in their relationships. This includes working to unearth all their implicit assumptions about relationships in general and their partner in particular. It means being willing to dialogue about uncomfortable topics that may produce temporary pain or conflict. It is not until they “clear the air,” learning to be more open and honest with themselves and their partners, that ISTPs will experience true satisfaction and wholeness in their relationships.
If you’re interested in learning more about Ti, Fe, and ITPs’ Ti-Fe struggles, as well as insight into ITPs’ growth and relationships, be sure to check out my INTP eBook:
The INTP: Personality, Careers, Relationships & the Quest for Truth and Meaning (top-selling and highest-rated INTP book on Amazon):
Celebrity ISTPs/ Famous People: Tom Cruise, Kobe Bryant, Michael Jordan, Lance Armstrong, Ted Cruz, Rand Paul, Paul Ryan