Polyvagal Theory Is a Map, Not the Territory

Polyvagal Theory has given the somatic field something genuinely useful. A language for nervous system states that meets people where they are, reduces shame, and opens a door that years of talk therapy sometimes couldn’t. But like any map, it can be mistaken for the territory it describes. And when that happens, both practitioners and clients lose something.

To understand what gets lost, it helps to start somewhere unexpected.

In cellular biology there is a process called dedifferentiation. A specialized cell, one that has already become part of a liver or a lung, reverts under the right conditions to its original undifferentiated state. It sheds the specialized identity it developed in response to its environment and returns to something more original, a kind of cellular ground state. From there, guided by signaling nodes, organizing centers of intelligence within the organism that sense what is most needed now, the cell respecializes. It becomes something more aligned with what the organism actually requires in the present rather than what it required before.

This is cellular regeneration. And it maps onto what deep healing of the whole self can look like more precisely than most psychological frameworks do.

Polyvagal Theory has incredible utility toward that end. But it tends to get practitioners halfway there.

Years ago I was working at Sierra Tucson, one of the more respected residential treatment centers in the country, seeing hundreds of individual clients a year. The work was going well, measurably so. Toward the end of their stays I would ask people what had helped most. A significant portion said some version of the same thing. Understanding themselves through the lens of the nervous system. Knowing that what was happening in them was not a character defect, not evidence of something fundamentally broken, but a nervous system that had learned to stay in threat response long past the moment the threat had passed.

That reframe was lifting shame off people in ways that years of insight-oriented therapy sometimes hadn’t touched.

The framework I was using to teach this was Polyvagal Theory.

For those less familiar with it, Polyvagal Theory was developed by Stephen Porges and rests on five core premises. You don’t need to know this section to follow the rest of the piece, but I include it for those who want the full picture.

1. The ventral vagal complex, a myelinated branch of the vagus nerve, evolved in mammals specifically to support social engagement, including facial expression, vocalization, and the capacity to feel safe with others
2. The sympathetic nervous system mediates the fight and flight response under conditions of threat
3. The dorsal vagal motor nucleus, an older unmyelinated branch, mediates the freeze and collapse response under conditions of extreme or inescapable threat
4. These three systems are organized in a hierarchical sequence, with social engagement coming online first, sympathetic activation second, and dorsal vagal shutdown last
5. Respiratory sinus arrhythmia, the natural fluctuation of heart rate with breathing, serves as a reliable index of vagal tone and therefore of a person’s capacity for social engagement and self-regulation

The clinical application of these premises gave practitioners a way to map where a client’s nervous system was at any given moment and, more importantly, a framework for understanding why people get stuck in patterns of threat response even when no present threat exists.

Around the same time I was working at Sierra Tucson, I found myself in a message exchange with Paul Grossman, a psychophysiologist who had been publishing rigorous critiques of Polyvagal Theory’s scientific foundations. His position, shared by a growing number of researchers, was that the theory’s core neurophysiological premises did not hold up under scrutiny.

You don’t need this section to follow the piece, but for those interested in the specific scientific objections, Grossman’s critique distilled:

1. The proposed distinction between ventral and dorsal vagal control of heart rate is not supported by neuroanatomical evidence; current research suggests vagal control of heart rate is mediated almost exclusively by the ventral nucleus ambiguus, not the dorsal motor nucleus
2. Respiratory sinus arrhythmia is not uniquely mammalian; similar cardiorespiratory coupling appears in reptiles and other non-mammalian vertebrates, which contradicts a foundational evolutionary claim of the theory
3. The freeze and collapse response attributed to dorsal vagal activation appears, on current evidence, to also be mediated by the ventral nucleus ambiguus, not the dorsal branch
4. The evolutionary sequence Porges describes, from ancient unmyelinated vagal pathways to newer myelinated ones, does not map cleanly onto comparative neuroanatomy
5. Using respiratory sinus arrhythmia as a proxy for overall vagal tone conflates a specific measurable phenomenon with a much broader physiological concept

I was sitting with a real problem. A framework producing genuine clinical results might not be scientifically grounded in the way I had assumed. So I asked Grossman directly. Does this invalidate the clinical work?

His answer has stayed with me. He said he was not arguing that there is no social engagement system. He was arguing that it has not been proven to correlate with the specific neural structures Polyvagal Theory attributes it to. The states we observe in people, the shift from threat response into something more open, more relational, more settled, those are real. The map just may not be drawn on the right neuroanatomy.

That was enough for me.

What Polyvagal Theory actually contributes in clinical practice, when used well, is a framework of nervous system states as an organizing lens for identity and shame. The idea that a person’s chronic patterns of reactivity, withdrawal, collapse, or vigilance are not personality flaws but learned autonomic responses. That the nervous system, given enough repetition of threat, simply gets stuck. Stuck is not the same as broken.

When I multiply what I observed in those individual sessions at Sierra Tucson across the more than a thousand clients I worked with there, and then multiply that again by the many thousands of practitioners now teaching Polyvagal Theory globally, the contribution is almost impossible to overstate. Not because the neuroanatomy is settled. Because the reframe works. People stop organizing their identity around shame and start understanding themselves as beings whose nervous systems learned something that no longer serves them.

Stephen Porges is also, worth saying, an exceptionally kind and sincere person. I recommend spending time around him if the opportunity arises.

But here is where the map starts to obscure the territory.

Polyvagal Theory does a good job of giving people space from their problems. Getting someone out of a shame-based identity and into a nervous system explanation is meaningful work. For someone who has spent years in institutions, being told they are not the problem is not a small thing.

The question is what comes next.

Back to that dedifferentiated cell. Shedding the specialized identity it developed under stress is not the endpoint. The cell has to respecialize. Those signaling nodes, the organism’s internal intelligence, guide it toward a form more aligned with what is actually needed now. The intelligence was always present. The conditions for it to express itself had to be created first.

In my book Get Over Trauma, Regenerate Your Life, I write about how deeper healing mirrors this biological sequence. First, helping someone understand that what is happening lives in their nervous system, not their character. Then working to deactivate the charge held there, the patterns of activation that have been running in the body, sometimes for decades. Then creating the conditions for them to discover who they actually are outside of a stress response. Not a corrected version of who they were under stress. Something closer to ground state. And then supporting them to bring that nature forward into how they move through the world, so that life begins to feel less like a constant negotiation against themselves.

This is the respecialization. And it requires a different clinical skill than teaching someone about their autonomic ladder.

It requires the capacity to see into a person and sense what is actually there underneath the pattern. To find the organizing intelligence that already knows what it needs. And to reflect that back with enough precision that the person can begin to recognize it in themselves.

Polyvagal Theory can get someone to the edge of that territory. It gives them language, a framework, a way to stop organizing themselves around shame. That is real and it matters.

The territory itself is the person who has not yet been fully seen.

If you are a practitioner working in this space and want to go deeper into what that kind of clinical perception actually looks like, the Somatic Practitioner Training at VOSESOMATIC is built around exactly this. The nervous system foundation, yes. But also the perceptual capacity to see into your clients and the skill to reflect what you find there.