Welcome to Typish, an Enneagram podcast where we explore how your personality shows up in all of life. I'm your host, Tyler Zach, and in each episode I connect you with leading experts on how your personality impacts your relationships, mental health, spirituality, and everything in between. In today's episode, I'm joined by Dr. Dan Siegel, New York Times bestselling author, psychiatrist, and one of the world's leading voices on interpersonal neurobiology. We discuss his groundbreaking book on the Enneagram, how a chance meeting with Ennea-types creator Claudio Naranjo changed the trajectory of his work, and why this once-skeptical neuroscientist spent the next two decades helping build a bridge between modern neuroscience and the Enneagram. You can stay up to date with all that Dan is doing at drdansiegel.com, where you can also find a link to his books, including Personality and Wholeness in Therapy: Integrating Nine Patterns of Developmental Pathways in Clinical Practice. Now, without further ado, let's jump into the interview.

Tyler Zach (02:14)

Dan, you are revered among therapists, doctors, Enneagram enthusiasts, and people of all backgrounds. I'm so grateful to have you on the summit. Could you begin by just sharing a little bit about what draws you to this work?

Dan Siegel (02:21)

Well, thank you, Tyler — and I'm on a walking desk, so you may see a little movement. As we walk through life, there are so many aspects of our reality: our spiritual life, our personal life with family, our professional life, our public life, what's happening on the planet. Years ago, when I began the work in interpersonal neurobiology, I was trying to think about a framework for understanding the mind and mental health that could apply to anyone working in any area of life. So I'm really very grateful that these efforts have found a home in so many different areas of human endeavor.

Tyler Zach (03:07)

My goal over the next hour — since we're bringing together the Enneagram and mental health on this summit — is to take our listeners on your own personal journey, seeing how these two things came together for you, and talking about your new book and how it blends them. My first question: you're a world-renowned expert on interpersonal neurobiology. What is that, and why is it a good starting point for understanding mental health?

Dan Siegel (03:46)

Yeah. The phrase "interpersonal neurobiology" is a term I came up with back in 1992 when I was assembling about 40 different academic colleagues from fields spanning anthropology and sociology to physics and math. We were looking at the inner nature of our subjective mental lives — that's the "personal" — and what was happening between people — that's the "inter." And it was the beginning of what was being called the decade of the brain, so we also had brain scientists in the room. Someone said, "What are you guys doing in that meeting?" and I said, "I guess it's interpersonal neurobiology." And that stuck.

Basically, it's a framework that takes every discipline of knowing — beginning with sciences from math and physics to sociology and anthropology — and branches out to spiritual traditions, contemplative traditions, indigenous wisdom, poetry, music, dance, philosophy, literature. The guiding light is what E. O. Wilson called consilience: what do all these different fields say when you put them in conversation? Is there common ground? The answer is yes. And that's where the excitement is. We welcome everybody into the tent.

We now have a whole library of over a hundred textbooks in the Norton professional series on interpersonal neurobiology — mostly written by other people, which I've edited. And we have a brick-and-mortar home where I work. Some of the teachings from thousands of years ago have been affirmed when you look at them through an interpersonal neurobiology lens, and that's part of what makes this work so compelling.

Tyler Zach (06:51)

One of the things that strikes me in your work is that at one point you realized nobody really had a good definition of the mind — which is remarkable, because there are lots of books on mental health and how to improve it, but we were having a hard time even knowing what the mind was. Can you describe your attempts at defining the mind and how a better understanding of it leads to mental health?

Dan Siegel (07:32)

Yeah. This was a shocking finding for me. When I switched from pediatrics into psychiatry, I felt very uncomfortable with how my field was approaching things. So I started doing research with psychologists. And while practicing as a psychotherapist, there was this exciting exploration of patients' inner subjective lives — how they experienced and expressed emotions, what they did with their memories and their narratives of who they were, their relationships. All of this could be placed under the framework of the mind and mental health.

Eventually, as the training director for that interdisciplinary group of 40 scientists, I brought up the central question: what is the relationship between brain and mind? Everyone could agree on what the brain was — this fascinating organ in your head connected to your body — but no one could define what the mind was. Not even my own field of psychiatry, which is supposedly the caretaker of the mind, nor psychology, which studies it. They study elements of it — memory, emotion, attention — but there was no actual definition of the mind.

I went for a long walk on the beach to think about this. I came back and asked the group to meet one more time before we fell apart entirely. I was looking for common ground — what E. O. Wilson would later call consilience. In the 1980s there was a whole field studying complex systems. Complex systems have something called emergent properties: when the elements of a system interact, something new arises. Water molecules in a cupped hand feel wet — that wetness is an emergent property of their interaction. No single molecule has wetness.

So I started asking: maybe the mind is an emergent property of a complex system. The brain is certainly part of that system, but you wouldn't want to stop at the skull — the body matters, as anyone who does Tai Chi or Qigong knows. And then I asked: what about relational communication? Energy flows between brains, between people — why would the skull and the skin be barriers? So I went back to the group and said: what if the mind is an emergent property of energy flow — whether that's subjective experience, consciousness, information processing, or what complex systems mathematics calls self-organization? And I offered a working definition: the mind is the embodied and relational emergent self-organizing process that regulates the flow of energy and information. It's a verb, not a noun.

We went around the room — 40 strong, opinionated academics — and every single one of them, without exception, said: I can go with that. We went on to meet regularly for four and a half years.

Tyler Zach (15:18)

In the 90s, as you were having these conversations, you intersected with the Enneagram — literally, by running into Claudio Naranjo, who is also a psychiatrist. Some people in faith communities have pushed back on the Enneagram because they see Naranjo as a new-age guru, not realizing he was a psychiatrist trained at Berkeley and Harvard, on the cutting edge of personality theory. I find it fascinating that you — a fellow psychiatrist — ran into him at the International Enneagram Conference in the 90s. Can you share what you discussed and how that meeting shaped things?

Dan Siegel (16:09)

Yeah, absolutely. As people who know the Enneagram's history know, Claudio Naranjo — a psychiatrist with deep training in personality research — traveled to South America to meet with Oscar Ichazo, who some would describe as a spiritual teacher. Together, they took what had been around for at least decades, possibly centuries — something about a nine-pointed figure — and proposed that this figure might be a window into nine different personality types, what they called Ennea-types. Naranjo then came back to Berkeley and started teaching them to SAT groups — Seekers After Truth.

When I met Claudio, it was at a moment when there had been some very painful disconnections between him and students who had gone out without his permission to teach the material. There were legal implications and very tense emotional fallout. He'd been invited back to the conference as one of the two co-founders of what was now being called the Enneagram of personality — different from the Enneagram symbol alone, which didn't address personality.

After he finished his talk, I noticed no one was going up to him. He was essentially the father of the whole field, and he was just standing there alone. I didn't know the backstory. I just wandered up and said, "Hey, do you want to go to lunch?" And he said yes. We had a long, long lunch, diving deeply into his perspective on the Enneagram of personality. He was a trained attachment researcher and therapist, as was I. It was a beautiful meeting. And it was the only time I would ever meet with him.

A few years later, I got a call from David Daniels and Denise Daniels. They were colleagues of Helen Palmer, who had been a direct student of Claudio's in the SAT group. Helen Palmer is a brilliant teacher in this field — also based in Berkeley — and she and David had co-founded a school called the Narrative Enneagram. David and Denise called and said: "We love your book The Developing Mind, but you missed temperament — you mostly talk about attachment." I said yes, because at that time there was no way to trace temperament into adult personality with any real statistical significance except at the extremes. They said, "Well, do you want to learn how adults experience temperament?" I said absolutely. So they invited me to a week-long retreat on the Enneagram through the Narrative Enneagram organization. I said: I'll come if you let me come as a scientist. They said sure, study whoever you want.

This was 2004 — over twenty years ago now. And I went in very doubtful. There was no science behind the Enneagram of personality. It was all impressions. But I was really impressed by the panel interviews — hearing people describe their inner experience in clusters. I gave people the adult attachment interview and informally collected impressions: did attachment determine Enneagram type? I also knew that fifty years of personality research had concluded there are no personality types — there are dimensions of personality, spectrums, but not fixed types. So I was genuinely concerned about the word "type." I was relieved to find that David himself said: "I don't really think they're types. They're something." And we started using the word "pattern" instead, because pattern implies dimensionality — you can tap into different patterns rather than being stuck in one.

At that retreat I also met two other science colleagues: Laura Baker, a professor of the genetics of temperament and personality, and Jack Killen, a researcher at the National Institutes of Health. So the five of us — David, Denise, Laura, Jack, and I — started meeting regularly, trying to figure out if there was a scientific understanding that could map onto the Enneagram. We tried this, tried that. The early efforts didn't stick. Eventually something clicked. Every time we tried to publish a peer-reviewed paper using the word "Enneagram," journals rejected us — saying there was no science behind the Enneagram, so they couldn't publish. The irony, of course, was that's exactly why we were trying to publish. Rejection after rejection.

Eventually I said: I'm busy writing books — let's just put the model in one of them. And we did, in The Mindful Therapist in 2010. That was enough. It was published. Then David passed away. He was in his late eighties and had lived a full life. At the funeral, Helen Palmer came up to the four of us and said: "What are you going to do with this project?" We said it was done — David was gone, it had been published. She said: "It can't be done. You have to put out the whole thing, not just a chapter." So we looked at each other and I appealed to my publisher. They had never published a book on the Enneagram, but if it was framed as an interpersonal neurobiology book in the interpersonal neurobiology series, maybe they'd say yes. And they did — on the condition that I be the main writer, since David was gone and had been the only one of us who'd written books before. So I did. But it was a totally collaborative project woven from twenty years of working together. That's the long story of how meeting Claudio Naranjo led to where we are now.

Tyler Zach (28:09)

I heard you mention at one point that you were categorizing people based on three vectors — agency, bonding, and certainty — and whether they had an inward focus of attention, an outward focus, or both. And when you started correlating those, you found they matched Enneagram patterns remarkably well. Could you walk us through that process?

Dan Siegel (29:11)

Yeah, absolutely. The process was deeply collaborative and genuinely fun — we share a sense of humor, so there was a lot of laughter. The challenge we gave ourselves was to take the Enneagram of personality — a beautiful, well-developed field — and see whether modern science had anything to say about these nine patterns, even though that field wasn't rooted in science.

We started with temperament. Before you even have experience, your nervous system has certain tendencies — a reactivity or sensitivity or rhythmicity. We dove deeply into the science of temperament and developmental neuroscience, particularly the subcortical areas, which are mostly formed at birth. And we drew on the work of Jaak Panksepp — a beautiful researcher some call the father of affective neuroscience, who also passed in 2017 like David. Jaak studied what he called motivational circuits in subcortical regions of the brain.

The first motivational circuit we identified as relevant to the Enneagram is what Jaak called the rage circuit — essentially a drive for agency, the embodied sense of empowerment. You feel this in the gut — the need to eat, to breathe, to act. We preferred the more neutral framing of agency over anger. When this is frustrated, you experience anger in all its forms: irritation, frustration, rage. We called this the A vector.

The second is what Jaak called the separation distress circuit — a motivation for relational connection. When this is frustrated, you experience sadness or separation distress. We called this bonding — the B vector.

The third is what Jaak associated with fear — a motivation for certainty, for predictability. If you can predict, you can protect. When this is frustrated, you feel anticipatory anxiety or fear. We called this the C vector.

So we had agency, bonding, and certainty — ABC. And we noticed that people seemed to orient with a particular primary vector. Agency corresponds loosely to what the Enneagram calls the gut or body center; bonding to the heart center; certainty to the head center. And where attention goes, neural firing flows and neural connection grows — so a small temperamental sensitivity in one of these areas, from very early in life, can become a deeply grooved pattern over time through the neuroplasticity of attention.

Then we asked: how do you get nine patterns from three vectors? We noticed that some people's attention tends inward, some outward, and some shimmer between the two — both inward and outward in a kind of dyadic fluctuation. I made up the word "attendancy" — a tendency of attention. And then I met with a friend for lunch and was despairing, saying: "This inward-outward thing feels impressionistic. Are we just making this up?" She said: "Dan, didn't you see my 2013 paper?" She showed me it on her phone. Mary Helen Immordino-Yang of USC had published empirical research showing exactly these three patterns of attentional focus: inward, outward, and both — with the third characterized as a kind of shimmering. That was the best birthday gift I've ever received. So it wasn't just impressionistic — there was independent empirical support.

When you combine the three vectors with the three attendancies, you get nine combinations — and these map remarkably well onto the nine Enneagram patterns. We tested this over and over in my own workshops, which had nothing to do with the Enneagram. About 80% of participants would broadly find themselves in one vector-and-attendancy combination as a baseline. About 10% could relate to three or four equally, and another 10% could relate to all nine. That's actually important to name — maybe 20% of people don't fit neatly into one pattern, and that's fine. That doesn't mean something's wrong with them. It may mean all three vectors were equally sensitive in their temperament, or that they had especially secure attachment histories.

And then here's the test I ran: I'd do this whole exercise without mentioning the Enneagram. Then I'd ask: does anyone know the Enneagram? About 20% would say yes. I'd ask those people: what's your type, and where did you land in the vector-attendancy combination? We got a very high positive hit rate. So the participants didn't know we were going to talk about the Enneagram — and still the correlations held. That's what made me feel this was real.

David Daniels had collected over 50,000 narratives in the Narrative Enneagram tradition over the decades he spent in this field. We drew on those as our primary data. And I'm trained as a narrative scientist — the adult attachment interview is essentially a narrative instrument, so I knew how to evaluate what a narrative is actually saying. I wasn't bothered that our data came from narratives. That's the science I'm trained in.

One more thing about the centers of intelligence, since this is something the Enneagram talks about: we don't believe the nine patterns are divided by a center of intelligence per se. We do think there's an anatomic location of energy activation and flow — agency in the gut, bonding in the heart, certainty up in the head. But we'd frame this as energy flow, not necessarily intelligence. Future research may show more — but for now, when I work with clients, I can literally practice directing attention from my head to my heart or to my gut. That's the therapeutic move. And it works.

Tyler Zach (41:26)

No, I love it — you're just going through my questions and answering them. So as a layperson, what I'm taking away is that the meeting with David Daniels and the others was a fascinating intersection — you'd done so much research on the cutting edge of neuroscience, and along comes David with 50,000 personal narratives. Even without formal scientific validation, you started seeing real correlations. And whether you call them types or patterns, you found nine meaningful clusters. When I'm doing trainings, I always talk about a "bundle of motivations" rather than a fixed type — trying to get away from the idea of being boxed in. That framing sounds very close to what you're describing.

I also wanted to ask about the scientific validation piece, because you are a scientist — and there are people who say we shouldn't use the Enneagram at all until we have studies that meet a certain standard. What gave you permission, as a scientist, to move from skepticism to actually teaching about the nine patterns?

Dan Siegel (43:27)

Good question. And you know, sometimes when you read a book, the first few pages are in Roman numerals. I noticed when I was editing this book that there were 34 introductory pages. I said, that's too many. I read it again and said, no — it's right. Because the first important thing to establish is this: the Enneagram of personality is not based on science in its origins. But that doesn't mean it's not valid. These are two separate questions. So just because something isn't rooted in science doesn't tell you anything about whether it's true or useful.

As a scientist full of doubts, I was questioning everything. I said to myself: unless these people have all been hypnotized to behave this way — or because no one has done a general population study — maybe only 2% of people fit into these Enneagram groupings, and those are the 2% who read the books and go to the workshops. So I started applying the PDP model in my own workshops that had nothing to do with the Enneagram, on unsuspecting participants who hadn't signed up for any Enneagram teaching.

And I started getting these statistics repeatedly: about 80% of people would broadly find themselves in one vector-and-attendancy combination. The rest — maybe 10% could relate to three or four, another 10% to all nine equally. So that was interesting data. It suggested that for a large majority of people, these patterns do seem to cluster in meaningful ways.

What gave me permission to move forward was a combination of things. First, the internal consistency of the model — the ABC vectors matched with the attendancy. Second, the independent empirical support from Immordino-Yang's research on inward vs. outward attention. Third, the high hit rate when people who knew the Enneagram self-identified their type and it matched their vector-attendancy combination. And fourth, the clinical validation — David and I were both therapists, and we tried it with our patients and it worked.

So what I'd say to scientists who are skeptical: don't confuse origin with validity. Study it. Test it. We did everything we could to test it, and we kept finding that something real was there. The fact that peer-reviewed journals rejected our papers because "there's no science behind the Enneagram" is a kind of circular reasoning — you can't produce the science if you can't publish the research.

The hypothesis we have about how these patterns originate is the most theoretical, speculative part of the model. Here's the short version: we believe that in the womb, before birth, you have an implicit memory of not being separated from anything — a felt sense of wholeness, communion, connection, fullness, tranquility. You don't consciously remember this later; it's stored in what we call implicit memory, which gives you bodily sensations, emotions, perceptions, and behaviors that when triggered later in life just feel familiar.

Then you're born. Now, if you don't breathe, you die. If you're not connected, you die. If your bodily needs aren't met, you die. It's literally do or die. We believe the contrast between the implicit memory of in-womb wholeness and the sudden disconnection of being out in the world — even just one day old — is so profound that it activates temperament. One of the three ABC vectors becomes particularly sensitive, based on something in the temperament of your nervous system. And whether your attention tends inward, outward, or both further shapes which pattern develops.

The neuroplasticity principle matters here: where attention goes, neural firing flows, and neural connection grows. A tiny temperamental sensitivity in infancy, compounded by non-secure attachment experiences, can dig the groove of a pattern deeper and deeper over time. Conversely, secure attachment — whether from early history or from the experience of good therapy — can lighten that groove, making the pattern more flexible, more accessible to integration. Instead of personality being a prison, it becomes more like a playground.

Tyler Zach (51:44)

I like that. I love it. And I just want to say thank you for your years of work. You've been so faithful to continuing to learn and grow, to take steps of courage, to do TED talks, to take up more space in the world — because you have something so valuable to give. And now you're seeing this flywheel effect where your books and talks continue to influence thousands of people every day. Thank you for being a pioneer across multiple fields and for bringing us all together. You're such a great gift to our community.

Dan Siegel (52:24)

Thank you, Tyler. I'll soak those words in and savor them. I hope we'll meet in person. I invite anyone listening — check out our website to find in-person events or online offerings. There are all sorts of opportunities to get together and dive deeply into the PDP framework.

I think that together — I use the word MWe, M-W-E, for "me and we" combined and integrated — we really can make this a kinder, more compassionate, more connected world for everyone. This whole model of looking at personality through this framework, I hope will be of service in bringing more connection into the world. Thank you, Tyler, for all the work you do, and thank you everyone for listening.