AJ Drenth is the founder of Personality Junkie and the author of several books exploring personality type through the lens of Jungian cognitive functions. He identifies as an INFP, and that identity shapes everything about how he approaches type theory: with depth, nuance, and a persistent interest in what’s happening beneath the surface of behavior. If you’ve ever read his work and felt like someone finally explained your inner world in a language that made sense, that’s not an accident.
Drenth’s contribution to MBTI discourse goes beyond simple type descriptions. He’s one of the few writers in this space who consistently grounds his work in cognitive function theory, which means he’s writing about why INFPs think and feel the way they do, not just what they tend to do. That distinction matters enormously if you’re trying to understand yourself rather than just recognize yourself.
Our INFP Personality Type hub covers the full picture of what it means to live and work as an INFP, and Drenth’s perspective adds a layer that’s worth examining on its own: the view from inside the type, written by someone who actually lives it.
Who Is AJ Drenth and Why Does His Work Resonate So Deeply?
Drenth founded Personality Junkie as a platform for serious type exploration, the kind that doesn’t flatten complex human beings into four-letter boxes. His books, including “The INFP Book” and “My True Type,” take a cognitive function approach that draws heavily from Carl Jung’s original work and the subsequent frameworks built around it. He writes with a scholar’s precision and a practitioner’s empathy, which is a rare combination in a space that often veers into either overly academic or frustratingly vague territory.
What makes Drenth’s work particularly valuable is his willingness to sit with complexity. He doesn’t oversimplify INFPs into dreamy idealists who just need to find their passion. He examines the actual cognitive architecture: dominant introverted Feeling (Fi), auxiliary extraverted Intuition (Ne), tertiary introverted Sensing (Si), and inferior extraverted Thinking (Te). He explores how those functions interact, where they create friction, and how that friction produces both the INFP’s gifts and their recurring struggles.
I’ve spent a lot of time with personality type frameworks over the years, partly out of professional necessity and partly out of genuine curiosity about why certain people approach problems the way they do. Running advertising agencies meant managing creative teams full of people who processed the world very differently from each other, and from me. Drenth’s writing helped me understand some of those differences at a level that went beyond “she’s just more sensitive” or “he’s just not a details person.”
What Does Dominant Fi Actually Mean for INFPs in Practice?
Drenth spends considerable time in his work explaining introverted Feeling, and it’s worth unpacking because Fi is consistently one of the most misunderstood functions in type theory. Fi doesn’t mean “emotional” in the way most people use that word. It means that INFPs evaluate experience through a deeply personal internal value system. They’re constantly running incoming information against an interior compass that asks: does this align with who I am and what I believe?
That process is largely invisible to the outside world, which creates a particular kind of misunderstanding. An INFP in a meeting might appear disengaged while actually processing the ethical implications of a decision at a level no one else in the room is considering. They’re not checked out. They’re doing something that doesn’t have an obvious external signal.
I watched this play out with a creative director I worked with for several years. She was an INFP, though we didn’t have that language at the time. She’d go quiet in client presentations, and I used to misread that as hesitation or lack of confidence. What I eventually understood was that she was filtering everything through her own sense of what was true and good, and if something felt off, she needed time to locate exactly why before she could speak to it. When she did speak, it was almost always the most important thing said in the room.
Drenth’s framing helped me see that dominant Fi creates a kind of integrity that can look like stubbornness from the outside. INFPs aren’t being difficult when they resist ideas that conflict with their values. They’re being exactly who they are, which is actually one of their most significant strengths in environments that reward authentic creative work.
How Does Ne Shape the Way INFPs Engage With Ideas?
If Fi is the INFP’s internal compass, auxiliary extraverted Intuition is the engine that keeps generating new territory to explore. Ne is a pattern-recognition function that operates outwardly, constantly scanning for connections, possibilities, and meanings that aren’t immediately obvious. In an INFP, Ne serves the dominant Fi: it generates ideas and perspectives that get filtered through personal values, producing a worldview that is both imaginative and deeply principled.
Drenth writes about how this combination creates what he describes as a search for authentic self-expression. INFPs aren’t just looking for interesting ideas; they’re looking for ideas that feel true to who they are. That’s a narrower filter than it might sound, and it explains why INFPs can seem prolific in their thinking but selective, sometimes agonizingly so, about what they actually commit to.
The Ne-Fi interplay also shapes how INFPs engage in conversation and conflict. They tend to approach disagreement by exploring multiple angles rather than staking out a fixed position immediately, which can frustrate more decisive types. But that exploratory quality is also what makes INFPs genuinely open to being changed by a conversation, which is rarer than most people realize. If you’re working through something difficult with an INFP, understanding how INFPs handle hard talks can help you meet them where they actually are rather than where you expect them to be.
From my own experience managing creative teams, the people who brought the most unexpected solutions to client problems were often the ones who needed the most time to sit with a brief before responding. That’s Ne doing its work quietly before it surfaces something worth saying.
Why Does Drenth’s Cognitive Function Approach Matter More Than Surface Descriptions?
Most popular MBTI content describes types by behavior: INFPs are creative, empathetic, idealistic, and prone to overthinking. Those descriptions aren’t wrong, but they don’t explain anything. They’re observations without mechanism. Drenth’s approach asks a different question: what cognitive processes produce those behavioral tendencies, and what does understanding those processes make possible?
That shift from description to explanation is significant. When you understand that an INFP’s tendency to take criticism personally isn’t a character flaw but a predictable expression of dominant Fi, you stop trying to fix the sensitivity and start working with it. The sensitivity is connected to the same function that makes INFPs exceptional at detecting inauthenticity, advocating for people who’ve been overlooked, and producing creative work that actually means something. You can’t selectively remove the parts you find inconvenient.
This connects directly to one of the more persistent challenges INFPs face in professional environments. Why INFPs take everything personally is a question worth examining carefully, because the answer isn’t “they’re too sensitive.” The answer has to do with how Fi processes interpersonal experience, and understanding that makes it possible to work with the function rather than against it.
Drenth’s writing consistently pushes readers toward that kind of functional understanding, which is why his work tends to resonate with people who’ve read dozens of type descriptions and still felt like something was missing. He’s not describing the surface. He’s mapping the interior.
What Does Drenth Say About the INFP’s Relationship With Authenticity?
Authenticity isn’t just a value INFPs happen to hold. According to Drenth’s framework, it’s a functional imperative. Because dominant Fi evaluates experience through personal values, any situation that requires sustained inauthenticity creates genuine cognitive dissonance for an INFP. It’s not uncomfortable in the way that, say, public speaking might be uncomfortable for an introvert. It’s more fundamental than that. Being required to act against core values doesn’t just feel bad; it creates a kind of internal fracture that’s difficult to sustain.
Drenth explores how this plays out in career choices, relationships, and creative work. INFPs who find themselves in roles that require them to suppress their values, or worse, to actively advocate for things they find ethically questionable, tend to experience a particular kind of exhaustion that goes beyond burnout. It’s more like a slow erosion of self.
I recognize something of this in my own experience, even as an INTJ. Spending years trying to perform an extroverted leadership style I didn’t actually possess created a fatigue that no amount of sleep fixed. The performance itself was draining, separate from the actual work. For INFPs, the stakes of inauthenticity are even higher because their dominant function is specifically oriented around internal alignment. What I experienced as a performance problem, an INFP might experience as an identity problem.
This is also why INFPs tend to be drawn to creative fields, counseling, writing, and advocacy work. These are domains where authentic self-expression isn’t just permitted; it’s often the primary value being delivered. The work and the person can align in ways that more transactional roles rarely allow.
How Does the INFP Compare to the INFJ Through Drenth’s Lens?
Drenth writes extensively about both INFPs and INFJs, and his comparative analysis is some of the most useful material in the type space. These two types are frequently confused with each other, partly because they share the NF temperament and partly because surface descriptions overlap significantly. Both are described as idealistic, empathetic, and drawn to meaning. But the cognitive functions are quite different, and those differences produce meaningfully distinct ways of moving through the world.
The INFJ leads with introverted Intuition (Ni) and uses extraverted Feeling (Fe) as the auxiliary function. The INFP leads with introverted Feeling (Fi) and uses extraverted Intuition (Ne) as the auxiliary. That reversal matters. INFJs process meaning through pattern convergence and then express care outwardly through Fe. INFPs process values internally through Fi and then explore possibilities outwardly through Ne. One converges; the other expands. One tends toward a singular vision; the other tends toward multiple authentic expressions.
In conflict, these differences become particularly visible. INFJs often struggle with what happens when their care for harmony collides with the need to address something real, which is why the hidden cost of keeping peace for INFJs is such a persistent theme. INFPs face a different tension: their deep personal values make conflict feel like a threat to identity rather than just a disagreement, which is a distinct challenge with its own set of responses.
Both types can struggle with communication blind spots that stem directly from their dominant functions. For INFJs, Fe can create a pattern of managing others’ emotions rather than expressing their own, which shows up as one of the more significant INFJ communication blind spots. For INFPs, Fi can create a pattern of assuming others share their internal value framework, which leads to genuine confusion when they don’t.
Understanding these distinctions, as Drenth lays them out, makes it possible to be more precise about what kind of support actually helps each type rather than applying generic “sensitive introvert” advice that misses the mark for both.
What Does Drenth’s Work Reveal About the INFP’s Inferior Function?
One of the most illuminating aspects of Drenth’s writing is his treatment of inferior functions, the least developed cognitive function in a type’s stack, which tends to emerge under stress in ways that feel foreign and destabilizing. For INFPs, the inferior function is extraverted Thinking (Te).
Te is concerned with external organization, efficiency, and measurable results. In its healthy expression, it helps people structure their environment, meet deadlines, and communicate clearly about objectives. For INFPs, who lead with Fi and whose natural orientation is inward and values-based, Te is the function they’re least comfortable with. Under significant stress, it can emerge in distorted forms: hypercritical judgments, sudden rigidity, or an uncharacteristic fixation on external standards that feel out of proportion to the situation.
Drenth’s framework suggests that developing a healthier relationship with Te is one of the key growth areas for INFPs. This doesn’t mean INFPs need to become systems thinkers or efficiency experts. It means developing enough comfort with Te to use it consciously rather than having it erupt when they’re overwhelmed. Practically, this might look like building simple organizational structures, learning to communicate expectations clearly, or finding ways to connect their values-driven work to measurable outcomes without feeling like they’re betraying what matters to them.
In agency work, I saw this pattern regularly with creative people who were exceptional at generating ideas and deeply committed to quality, but who struggled enormously with project management, deadlines, and client communication about deliverables. The struggle wasn’t laziness or disorganization as a personality trait. It was an underdeveloped Te that hadn’t been given the right kind of support to function well.
How Does Drenth’s INFP Framework Apply to Conflict and Relationships?
Drenth’s cognitive function approach has practical implications for how INFPs handle interpersonal friction, and it reframes some patterns that are often described in purely negative terms. INFPs are sometimes characterized as conflict-avoidant or emotionally fragile in disagreement. Drenth’s framework suggests something more precise: because Fi evaluates experience through personal values, conflict that touches on those values feels fundamentally different from conflict about logistics or preferences. It’s not that INFPs can’t handle disagreement. It’s that certain kinds of disagreement carry a weight that other types don’t always register.
This distinction matters for anyone in a relationship with an INFP, professional or personal. A debate about project direction might feel relatively neutral to an INTJ or an ESTJ. To an INFP, if that project is connected to something they genuinely believe in, the same debate can feel like a challenge to their integrity. Knowing that going in changes how you approach the conversation.
There’s also a parallel worth noting with INFJs, who face their own version of this challenge. INFJs can become so focused on maintaining harmony through Fe that they avoid necessary confrontation until the pressure becomes unsustainable, which is one of the reasons the INFJ door slam exists as a pattern at all. The INFP version is different: rather than suppressing conflict until it explodes, INFPs more often withdraw into their internal world and process privately, sometimes for much longer than the people around them realize.
Both patterns, the INFJ door slam and the INFP internal retreat, have roots in the same underlying dynamic: a type whose dominant function is introverted and values-oriented finding the external world of conflict genuinely costly to engage with. The expression differs, but the source is similar. And in both cases, developing more conscious approaches to conflict, rather than defaulting to avoidance or withdrawal, tends to produce better outcomes for everyone involved.
For INFJs specifically, how quiet intensity actually works as influence is worth examining alongside conflict patterns, because INFJs often have more relational leverage than they realize, and using it consciously is far more effective than either avoiding conflict or absorbing it silently.
What Can Non-INFPs Learn From Drenth’s Work?
Drenth’s writing is addressed primarily to INFPs, but the value extends well beyond the type. His approach models something that’s genuinely rare in popular psychology: the willingness to explain a type’s behavior in terms of underlying cognitive processes rather than surface traits, and to do so without pathologizing the type in the process.
For leaders and managers, understanding the cognitive function stack of the people you work with changes how you interpret behavior that might otherwise read as problematic. An INFP who goes quiet in a brainstorm isn’t disengaged. An INFP who pushes back on a direction that seems efficient and practical isn’t being obstructionist. An INFP who needs more time to commit to a decision isn’t being indecisive for its own sake. These behaviors make sense when you understand the function behind them.
I spent too many years in agency leadership interpreting quietness as a performance problem. Some of the most valuable people I ever worked with were quiet in exactly the ways Drenth describes, and I didn’t always create the conditions where their actual strengths could surface. That’s a leadership failure, not a personality failure on their part.
If you’re not sure where you fall on the type spectrum, our free MBTI personality test is a good starting point. It won’t replace deep reading like Drenth’s work, but it gives you a framework to begin with.
Drenth’s broader contribution is demonstrating that personality type, taken seriously and understood at the level of cognitive function, is a genuinely useful tool for self-understanding and for understanding others. Not because it puts people in boxes, but because it explains the patterns that otherwise seem arbitrary or frustrating.
Where Does Drenth’s Perspective Fit in the Larger MBTI Conversation?
The MBTI space has a credibility problem that Drenth’s work partly addresses. Much of what circulates online as type content is either superficial (personality as aesthetic) or overclaiming (type as destiny). The more rigorous end of the conversation, grounded in Jung’s original cognitive function theory and informed by ongoing psychological research, tends to be harder to find and harder to read.
Drenth occupies a useful middle position. He takes cognitive functions seriously and writes about them with genuine depth, drawing on frameworks that have real theoretical grounding. A useful overview of how personality frameworks are structured and what they’re actually measuring can be found at 16Personalities’ theory page, which explains the dimensional approach underlying modern type assessments. Drenth goes further than most in connecting those dimensions to functional cognition.
At the same time, he writes accessibly. His books aren’t academic texts. They’re written for people who want to understand themselves, not for researchers studying personality taxonomy. That combination of rigor and accessibility is genuinely difficult to achieve, and it’s a significant part of why his work has found such a wide audience among people who take type seriously.
It’s also worth noting what Drenth doesn’t claim. He doesn’t argue that MBTI is equivalent to Big Five trait measurement or that type determines outcome. He uses the framework as a lens for understanding cognitive preferences, which is what it’s actually designed to do. That restraint matters in a space where overclaiming is common. Personality psychology as a field has moved significantly in recent decades, as documented in this PMC review on personality trait stability and change, and responsible type writers situate their claims accordingly.
One area where Drenth is particularly careful is the distinction between MBTI concepts and adjacent frameworks. Empathy, for instance, is a psychological construct with its own research base, as Psychology Today’s empathy overview describes. INFPs are often described as deeply empathetic, and many are, but empathy as a construct is distinct from the MBTI framework. Drenth tends to be precise about these distinctions in ways that less careful writers aren’t, which makes his work more reliable as a reference.
The question of how personality traits relate to wellbeing and interpersonal functioning is also worth taking seriously. This PMC study on personality and psychological wellbeing offers relevant context for understanding how individual differences in values orientation and emotional processing connect to broader outcomes, which is the territory Drenth’s work in the end inhabits.
What Makes Drenth’s Self-Identification as an INFP Significant?
There’s something worth examining in the fact that Drenth doesn’t just write about INFPs from the outside. He writes as one. That’s not a small thing. First-person type knowledge, the kind that comes from actually living a cognitive function stack, produces a different quality of insight than purely theoretical analysis can.
When Drenth describes the INFP’s experience of being misunderstood in environments that reward extroverted performance, or the particular exhaustion of having to justify deeply held values to people who don’t share them, or the way dominant Fi can create a sense of isolation even in the middle of a crowd, he’s describing something he knows from the inside. That shows in the writing. It’s specific in ways that purely external analysis tends not to be.
This is also, I think, why his work resonates with readers who’ve felt unseen by more generic type descriptions. Being described accurately by someone who shares your cognitive wiring feels different from being described by someone who has studied you from a distance. There’s a quality of recognition in Drenth’s INFP writing that his readers consistently mention, and I think it comes directly from this.
For anyone working through questions about their own type, particularly at the NF end of the spectrum, Drenth’s books are worth the time. They won’t give you a simple answer, but they’ll give you a more accurate one. And for INFPs specifically, reading someone who genuinely understands the interior experience of dominant Fi can be one of those rare moments where you stop feeling like you need to explain yourself and start feeling like you’ve finally been understood.
Explore more about the full INFP experience, including strengths, challenges, career paths, and relationships, in our complete INFP Personality Type hub.
About the Author
Keith Lacy is an introvert who’s learned to embrace his true self later in life. After 20 years in advertising and marketing leadership, including running agencies and managing Fortune 500 accounts, Keith now channels his experience into helping fellow introverts understand their strengths and build fulfilling careers. As an INTJ, he brings analytical depth and authentic perspective to every article, drawing from both professional expertise and personal growth.
Frequently Asked Questions
Is AJ Drenth actually an INFP?
Yes, AJ Drenth identifies as an INFP and writes extensively from that perspective. His self-identification as an INFP informs the depth and specificity of his work on the type, particularly his treatment of dominant introverted Feeling and how it shapes the INFP’s inner life and external behavior. He founded Personality Junkie and has authored several books on personality type from a cognitive function perspective.
What is AJ Drenth’s approach to MBTI and personality type?
Drenth takes a cognitive function approach to personality type, grounding his work in Jungian theory rather than relying solely on behavioral descriptions. He examines how the four functions in a type’s stack (dominant, auxiliary, tertiary, and inferior) interact to produce the patterns that define each type. For INFPs, this means exploring how dominant Fi, auxiliary Ne, tertiary Si, and inferior Te work together and where they create both strengths and challenges.
What is the INFP cognitive function stack?
The INFP cognitive function stack is: dominant introverted Feeling (Fi), auxiliary extraverted Intuition (Ne), tertiary introverted Sensing (Si), and inferior extraverted Thinking (Te). Dominant Fi means INFPs evaluate experience through a deeply personal internal value system. Auxiliary Ne provides an outward-facing pattern-recognition and possibility-generating function. Tertiary Si connects present experience to past impressions. Inferior Te is the least developed function and tends to emerge under stress in distorted forms.
How does Drenth distinguish INFPs from INFJs?
Drenth draws a clear distinction between INFPs and INFJs based on their cognitive function stacks. INFPs lead with introverted Feeling (Fi) and use extraverted Intuition (Ne) as their auxiliary function. INFJs lead with introverted Intuition (Ni) and use extraverted Feeling (Fe) as their auxiliary. This means INFPs are primarily oriented around personal values and authentic self-expression, while INFJs are primarily oriented around pattern convergence and outward care for others. The surface similarities between the two types mask significant functional differences.
Where can I read AJ Drenth’s work on the INFP?
Drenth’s work is available through Personality Junkie, his website dedicated to in-depth personality type exploration. He has authored several books including “The INFP Book” and “My True Type,” both of which approach type through the cognitive function framework. His writing is particularly valuable for readers who find standard type descriptions too surface-level and want a more thorough account of what’s happening cognitively beneath the behavioral patterns associated with each type.
