After penning two books on the INTP personality type, I took a break and wrote about other topics for a few years. More recently, however, I’ve found myself reflecting on the ways in which INTPs resemble their ISTP counterparts. While I haven’t lost sight of their important differences, it’s inspired me to further explore and compare these two types, which will serve as our objective in this post.
While acknowledging that INTPs and ISTPs (“ITPs” collectively) can be a bit wary of anecdotal evidence, I’m an INTP who grew up with an ISTP father. I’ve also personally intersected with a number of INTPs and ISTPs over the years. This, in conjunction with my longstanding immersion in and contributions to the personality literature, has offered me an intimate picture of many of their key character traits.
Readers familiar with the 8 cognitive functions and “function stack” are likely aware that INTPs and ISTPs employ the same dominant function—Introverted Thinking (Ti)—as well as inferior function—Extraverted Feeling (Fe).
Due to Ti’s introverted nature, outside observers don’t have ready access to this chief cognitive process and signature strength of ITPs. Instead, they encounter some combination of ITPs’ auxiliary (Ne or Se) and inferior functions (Fe), both of which are extraverted and hence more conducive to external observation. Unfortunately, this makes ITPs (along with other introverted types) more susceptible to being misunderstood, as the foundational piece of their personality remains largely veiled behind an extraverted persona used to navigate a social landscape in which Ti can seem an ineffective or unwelcomed function.
INTPs’ & ISTPs’ Outer Persona
Unlike the more assertive version of Extraverted Feeling seen in EFJ types (for whom Fe is dominant), ITPs’ Fe tends to manifest as general adherence to norms of social engagement. Due to ITPs’ general discomfort with navigating social and emotional affairs, not to mention their lack of trust and access to their own emotions, they rely on norms of social manner and expression as a sort of proxy or crutch. They essentially imitate, not unlike an actor, socially typical behavior. This practice of compensating for personality deficiencies through imitation is commonplace for all types, although differing according to which inferior function is involved.
The precise nature of ITPs’ social mimicry will of course vary by culture. In most parts of the U.S., for instance, the social norm involves being friendly and at least moderately engaging in social settings. So what one often encounters in ITP (and ETP) social behavior is their best attempt at warmth and affability. In this respect, ITPs differ from ETPs only in degree (i.e., being more toned down or exhibiting less social endurance) rather than kind.
That said, anyone who’s had the chance to know ITPs more intimately realizes that this public persona is just that—a persona. This public – private distinction shows up in a couple of ways. First, ITPs aren’t nearly as laid back or easy going as their persona suggests. They can quickly become bored or restless in casual conversations, especially if their Ti logic isn’t being engaged. ISTPs, in particular, would rather partake in a shared task or activity than sit around talking. Moreover, both types find it easier to find flow when they’re alone pursuing their own projects or interests. Given the right project, ITPs will happily disappear for hours, a propensity belied by their friendly social façade.
Onlookers may also fail to realize that ITPs can be inwardly rather cold, calculating, and self-absorbed (Ti). Indeed, the greater the psychological gulf between their Ti and Fe, the more emotionally disconnected they tend to be. Even when their Ti seems to have everything under control, whether ITPs know it or it, they still have emotional issues that need to be addressed or expressed in some way.
ITPs who are higher in Neuroticism can be particularly moody, impatient, and grouchy behind closed doors. Much to the surprise (and chagrin) of others, their habitual emotional repression (especially of negative emotions) can lead to occasional volcanic eruptions of anger. It’s not unusual for Neurotic or less developed ITPs to exhibit a sort of Jekyll and Hyde character. They can lay it on thick in public, but may become a different person once their social mask is off. Hence, intimates typically note at least some level of hypocrisy or inconsistency between ITPs’ public and private selves.
Whether they realize it or not, what ITPs ultimately want is to be accepted for who they are across the board. They want their inner (I) and outer (E), private and public selves, to be consistent and authentic, and for others to appreciate and accept them—introverted quirks and all. But until they figure out how to pull off that psychological magic trick, they worry others won’t accept them without some level of social veneer.
Cognitive Overlaps in Introverted Thinking (Ti)
As we’ve seen, ITPs use Introverted Thinking (Ti) as their dominant function. This is important to keep in mind because many theorists (myself included), have at times overstated INTP-ISTP differences and glossed over their similarities.
Propelled by Ti, ITPs are skeptics and critics by nature. Characteristically cautious and measured in their cognition and attestations, they’re generally less prone to the wild speculations or quasi magical thinking seen in other types. They may even be leery of putative “facts,” in part due to concerns of bias or motivated reasoning. That said, INTPs seem more willing (perhaps more than all other types) to go a step further and consider their own biases before accusing others of foul play.
According to Dario Nardi, Ti can also be associated with spatial or mechanical reasoning, as seen in activities like hitting a ball or shooting a target. Similarly, author Lenore Thomson has linked it with kinesthetic reasoning, such as calibrating the swing of a hammer. In these examples, Ti isn’t working with ideas (at least not consciously) but is employing tacit, behind-the-scenes reasoning to regulate motor output. This proves quite useful in tasks requiring fluid logic or instinctive mechanical know-how.
ITPs may also invoke Ti for self-direction in the pursuit of envisioned goals or objectives. Aspiring ITP athletes, for instance, might use it to develop and oversee their training regimen. Classic “DIY-ers,” ITPs enjoy formulating their own approach, trusting their own Ti powers to lead them in the right direction (yes, this includes not asking for directions!).
Points of Divergence: Extraverted Intuition (Ne) vs. Extraverted Sensing (Se)
Despite similarities in their persona (Fe) and cognition (Ti), INTPs and ISTPs part ways when it comes to their auxiliary and tertiary functions. Most relevant for our purposes here are differences stemming from their auxiliary functions: INTPs’ Extraverted Intuition (Ne) and ISTPs’ Extraverted Sensing (Se).
Ne is characteristically ideational, abstractly connecting and entertaining ideas, theories, and possibilities. When teamed up with Ti, it typically produces an intellectual orientation, as seen in the Enneagram type 5. While INTPs aren’t terribly well suited to formal scientific work, they are natural investigators and creative problem solvers. The wheels of the INTP mind are always turning, processing whatever the problem or idea du jour happens to be. Interest wise, similar numbers of INTPs are drawn to tech and engineering versus the arts and humanities.
Se, by contrast, is more concrete and empirical, gathering new information by way of the five senses. It’s stimulated by novel sensory experiences and pleasures, as well as by physical action and “doing.” This is why ISTPs typically enjoy athletics, which provide a steady stream of new and unpredictable challenges to perceive and respond to. Due to their ability to observe and quickly respond to their environment, many ISTPs appreciate and excel at hands-on tasks and trades—well suited to the Ti-Se function combination.
According to MBTI research, Intuition (N) correlates with both creativity and IQ. Hence, individuals higher in creativity and/or IQ may be more apt to identify as INTPs. I’m inclined to think of Ti in terms of logical or mechanical intelligence, whereas Intuition plays a bigger role in creativity, verbal intelligence, and unconventional thinking. Hence, given the same level of raw intelligence, we’d expect INTPs to outperform ISTPs in the latter mentioned areas. However, ISTPs are likely to outdo INTPs in activities requiring greater physical strength, coordination, or observational powers—be it as athletes, dancers, pilots, chefs, mechanics, drummers, carpenters, surgeons, etc.
Ideally, if personality, interests, and abilities converge, ITPs will gravitate toward interests they’re also naturally good at. When this is the case, interests may be indicative of type differences. But it would be foolish to rely on interests alone for type identification.
For instance, nearly all ISTPs seem to enjoy watching sports in some form. But many INTPs enjoy sports as well, although typically less so than intellectual or creative activities. Likewise, INTPs are more apt to be readers, but this doesn’t hold true in all cases. So while interests can play a role in type differentiation, they don’t give us the whole story. There will always be exceptions to the typical “personality – interest – ability” predictions. IQ (as well as other ability measures) is an important factor, influencing which interests and careers are feasible and enticing for a given ITP.
Many INTPs enjoy (or imagine they would enjoy) a bohemian lifestyle—an idiosyncratic life of the mind with little concern for money or possessions. Some may even dream of living in a commune, an Ne-Fe fantasy which, if ever enacted, might well prove to be more of a nightmare.
That said, most INTPs will spend the majority of their life in more or less conventional living arrangements. To some extent, this bourgeois normalcy may irritate them and engender subversive attitudes. But conventional lifestyles aren’t always the worst thing for INTPs, furnishing a baseline stability they might otherwise fail to achieve. On the whole, INTPs (especially non-tech INTPs) tend to be less content with their lives and thus devote ample time to pondering alternative life paths and possibilities. But whether they manage to muster the courage and means to actually implement these ideas is another question entirely.
ISTPs typically exhibit more conventional attitudes and lifestyles. Compared to INTPs, they are less apt to question or rail against the status quo. Moreover, some (though certainly not all) ISTPs have “high” taste—be it for food, wine, cars, accommodations, etc. Not only are these things pleasurable in an Se sense, but they can also serve as status symbols, which ISTPs tend to appreciate.
Most ISTPs work hard to provide for their families and, in large part, are willing to partake in the proverbial rat race. They seem more willing to sacrifice personal enjoyment of their work for the sake of income, status, or duty than most INTPs are.
Paths to Growth
INTPs’ first step toward growth involves greater use and development of their auxiliary Ne, typically through investment in creative or investigative careers or hobbies. The analog for ISTPs is Se development, which entails more concrete action or novel sensory experiences.
Broadly speaking, both Ne and Se are divergent functions, suggesting that ITPs’ type development will involve expanding their outer horizons, be it ideationally or experientially. It means intentionally stepping out of their introverted comfort zone, challenging their excuses, and saying “yes” more often (ITPs are notorious naysayers), especially to novel activities or challenges. Constantly “playing it safe” is a growth killer for ITPs and something they may come to regret later in life.
As alluded to earlier, the summon bonum for ITPs is connecting their dominant Ti and inferior Fe in a meaningful and satisfying way. But as discussed in my post, Two Paths to Type Development, the most reliable way of doing so is an indirect one, namely, by developing the auxiliary and tertiary functions in the middle portion of their function stack. These functions can be envisioned as a sort of bridge between the dominant and inferior functions. In the case of ITPs, these middle functions are perceiving (P) functions, pointing to the need for greater openness and receptivity of both mind (N) and body (S). While direct relational work (Fe) is certainly important for ITPs (including therapy in many cases), learning to let go and simply be present with their partner (which requires some relaxing of mind, body, and ego) can pave the way for a more fruitful F existence and relationship. Without a certain level of mind-body wisdom, it’s easy for the ego to keep its guard up and continue roadblocking key emotional pathways. Once these walls become more permeable, however, ITPs can gain access to profoundly rewarding emotional territories they never knew existed.
Learn More about ITPs in Our Books:
Learn more about INTPs and ISTPs—their personality, cognition, life struggles, and more—in our books: