Why It’s Time to Move Beyond the Polyvagal Theory

“What if the foundations of one of today’s most popular trauma theories were millions of years off?”

Let’s honour what it offered, and face what science now tells us

For more than two decades, Polyvagal Theory has been a beloved framework among therapists, coaches, and trauma-informed practitioners around the world. It gave us a fresh language for understanding the nervous system. It helped bridge the gap between emotion and biology, between stress responses and safety, between brain and body.

And for many, including myself, it sparked deep curiosity and compassion.

The theory introduced the idea that our autonomic nervous system is not just reactive, but intelligent. That we don’t simply fight or flee, but also freeze, fawn, or socially engage based on subtle internal cues of safety or threat. According to Polyvagal Theory, the vagus nerve has two branches: one associated with collapse and immobilisation (the dorsal vagal complex), and one with co-regulation and connection (the ventral vagal complex).

This story resonated. It offered elegant explanations for complex human responses. It empowered coaches and therapists to work with the body, not just the mind. It opened a door.

But science—like people must evolve.

We Can Appreciate a Model—and Still Outgrow It

Let me be clear: Polyvagal Theory served a purpose. It made the autonomic nervous system accessible—not just to neuroscientists, but to professionals working on the frontlines of change: coaches, therapists, teachers, and leaders. In that sense, it democratised physiology. And that matters.

However, a model can be culturally influential yet scientifically flawed.

As a professional working at the intersection of neuroscience, behaviour, and leadership, I believe we have a responsibility to continually learn, question, and stay aligned with the most accurate biological insights available, especially when those insights shape how we work with real people, real pain, and real transformation.

This is where the cracks in the Polyvagal framework begin to show.

When Simplicity Becomes Oversimplification

The challenge with Polyvagal Theory isn’t its ambition—it’s its reductionism.

It compressed the rich complexity of the nervous system into neat, dualistic categories and built an entire behavioural model on them.

In doing so, it made three critical errors:

• It misrepresented key neuroanatomical functions.

• It overlooked established research in evolutionary physiology.

• It encouraged binary interpretations of safety vs. shutdown, which rarely reflect how humans actually operate.

Over the past decade, multiple peer-reviewed studies have raised serious scientific concerns about the theory’s core premises. These are not minor quibbles. They strike at the foundation of the model.

But here’s the heart of it:

As professionals who care about healing, change, and human potential, we owe it to ourselves—and our clients—to work with models that are not only inspiring but also accurate and reliable.

Three Scientific Findings That Undermine Polyvagal Theory

1. The Evolutionary Story Doesn’t Add Up

Polyvagal Theory suggests that myelinated vagal fibres regulating heart rate are a relatively recent mammalian innovation, tied to what it calls the “social engagement system.”

It’s a beautiful idea and has always been appealing. It frames connection as a higher-order survival strategy, unique to humans and some other mammals. One that places human connection at the pinnacle of evolution. But it’s incorrect.

It’s not supported by comparative neurobiology.

A landmark study by Neuhuber and Berthoud (2021) revealed that myelinated cardioinhibitory neurons are present in species as ancient as sharks. In sharks, these neurons account for 45% of all cardiac vagal fibres.

Their conclusion is unambiguous:

“Myelinated cardioinhibitory neurons are phylogenetically highly conserved and not a new trait specific to mammals as proposed by the Polyvagal Theory.”

In short, this function is millions of years older than Polyvagal Theory claims; the evolutionary narrative at the heart of the theory doesn’t hold.

2. The Dorsal Vagal Shutdown Narrative Doesn’t Hold

One of the most popular and widely adopted concepts in Polyvagal Theory is that the dorsal vagal motor nucleus (DVMN) is responsible for “shutdown” states, such as freeze, collapse, and dissociation in humans.

It suggests that under extreme stress, this branch of the vagus nerve takes over, shutting down physiological functions and creating states of dissociation or immobilisation.

This has become a go-to explanation for many trauma responses.

However, this concept doesn’t align with current neuroanatomical understanding.

But research tells a different story.

A 2022 article in Nature by Veerakumar et al. clearly states:

“Cardiac parasympathetic outflow originates primarily from the nucleus ambiguus (NA)... The dorsal motor nucleus of the vagus controls ventricular inotropy and excitability, but does not control heart rate.”

This is a crucial distinction.

It’s critical because if the DVMN does not regulate heart rate, then it cannot be the driving mechanism behind the types of bradycardia or “shutdown” responses that Polyvagal Theory suggests.

Even more revealing, Professor Alexander Gourine—an internationally recognised leader in autonomic neuroscience—confirmed to me:

“Stimulation of the DVMN produces only a minimal drop in heart rate—about 5%. This is likely caused by acetylcholine spill-over from nearby organs. In contrast, stimulation of the nucleus ambiguus can stop the heart almost instantly.”

In other words, the DVMN is not responsible for immobilisation or dissociation—the foundation of the Polyvagal "shutdown" idea.

The implication is clear: the cornerstone of Polyvagal’s “shutdown” model is based on a functional error.

3. It Overlooks Decades of Comparative Physiology

Beyond the anatomical inaccuracies, Polyvagal Theory has also been criticised for ignoring decades of research in comparative evolutionary cardiovascular biology.

One of the leading voices in this critique is Professor E.W. Taylor, a world-renowned evolutionary biologist specialising in cardio-respiratory control in vertebrates.

In a 2020 article co-authored with Tobias Wang and C.A.C. Leite, Taylor outlines how the Polyvagal framework fails to account for the established evolutionary development of the vagus nerve across species.

His words are direct:

“The Polyvagal Theory blatantly dismisses decades of studies in comparative cardiovascular physiology. Enough is enough…”

This criticism isn’t about semantics—it’s about scientific rigour. When a theory ignores large bodies of established evidence, its utility becomes deeply questionable.

Why It Matters: Accuracy Shapes Transformation

You might ask:

“Isn’t this all a bit technical? Does it really matter which part of the brainstem controls which nerve?”

Yes. It matters deeply.

But here’s the truth: The models we use shape how we interpret human experience. They shape the methods we work with ..… and those methods shape outcomes.

If we misunderstand how the nervous system actually functions, we may misinterpret a client’s behaviour.

• We may misread our clients’ responses.

• We may reinforce the very coping strategies they’re trying to shift.

• We may limit the pathways to integration and growth

• Misidentifying protective patterns as dysfunctions,

• Over-pathologising responses that are actually adaptive,

• And limiting the options our clients or teams have for change.

That’s why we need a model that reflects not just psychology, but neurobiology—one that’s backed by anatomy, function, and evolution, not just theory.

That’s why it’s time to move forward—toward a model that honours complexity, respects biology, and integrates all of us.

The more accurate our understanding of the nervous system, the more empowered we are to support lasting transformation, not just soothing symptoms.

The question, then, is:

Where do we go from here?

What model can offer the same accessibility and body-based insight, but grounded in modern biology, with the flexibility to support personal transformation, trauma recovery, leadership, and systemic change?

That’s where the 3 Brains Intelligence model comes in.

The Path Forward: Introducing 3 Brains Intelligence

When Polyvagal Theory helped people see the nervous system as intelligent, it opened the door.

Now, it’s time to walk through that door—and into a more complete model: 3 Brains Intelligence.

Your nervous system doesn’t only reside in your head.

It’s distributed—intelligently—throughout your body.

Modern neuroanatomy confirms that we have three complex neural networks, each with the capacity to process information, store memory, and influence behaviour:

🧠 The Head Brain

• It houses approximately 86 billion neurons and governs most conscious thought.

• Functions: logic, language, reasoning, planning, cause and effect analyses, and predicting

💖 The Heart Brain

• Contains approximately 100,000 neurons and has its own independent processing capabilities.

• Functions: emotion, connection, values, relational safety, and teambuilding

• Heart rate variability research shows how deeply emotions are linked to cardiac rhythms.

  
  

💪 The Gut Brain

• Hosts over 500 million neurons, making it the second-largest neural network in the body.

• Functions: achieving, intuition, confidence, instinct, the immune system and digestion

• Produces 90–95% of the body’s serotonin and all the other neurotransmitters and hormones to keep us alive. 

These are not metaphors.

They are real, biological systems that process input, store emotional and procedural memory, and communicate through the vagus nerve, spinal cord, and neuroendocrine channels.

Why This Matters for Coaches, Leaders, Change-Makers and actually all of us

The 3 Brains Intelligence model offers a practical way to understand why we sometimes feel blocked, divided, or inconsistent—even when we “know better.”

Each brain can have its own agenda:

• Your Head Brain might say: “Be logical—don’t take the risk.”

• Your Heart Brain feels: “But I love this idea.”

• Your Gut Brain senses: “Something’s not safe.”

When these three brains aren’t aligned, internal resistance, self-sabotage, overthinking, emotional overwhelm, and decision fatigue emerge. However, when they are aligned, we gain clarity, flow, and a deeply embodied confidence.

That’s the power of working with—not against—our biology.

The Difference Between Alignment and Override

Most personal development strategies are based on the override model:

• "Push through the fear."

• "Ignore your gut—go with reason."

• "Don’t let emotions cloud your judgment."

While these approaches may create short-term results, they disconnect us from vital somatic information. They divide the self rather than integrate it.

In contrast, 3 Brains Intelligence teaches that true transformation happens through integration, not domination.

By listening to and aligning the Head, Heart and Gut, clients gain access to sustainable insight and action, whether they’re navigating:

• A career transition,

• Relationship struggles,

• Identity evolution,

• Trauma recovery, or

• Executive-level decision-making.

The Science of Alignment

This model is built on:

• Research in neurocardiology (Dr. Armour, Dr. McCraty),

• Enteric neuroscience (Dr. Gershon),

• Neuroplasticity, interoception, and affective neuroscience,

• And the lived experience of working with over 13,000 clients across 33 countries.

It aligns with ICF and EMCC coaching competencies, as well as principles of trauma-informed care, without relying on oversimplified narratives, such as the dorsal vagal “shutdown” or mammalian-only engagement systems.

And most importantly,

it works in practice.

From Theory to Practice

Through coaching, training, and leadership development programmes, 3 Brains Intelligence helps people:

• Understand their dominant brain (via a free test),

• Identify misalignment between Head, Heart and Gut,

• Resolve internal conflict,

• Break through limiting beliefs, and

• Step into whole-self leadership.

Try It for Yourself

🧭 Curious which brain is currently guiding your decisions?Take the free 3 Brains Dominance Assessment and discover your inner CEO configuration:

👉 https://www.3brainsintelligence.com/3-brains-preference-dominance-assesment

Because lasting change doesn’t come from choosing one brain over the others, it comes from aligning all three.

Final Words: From Parts to Whole

If Polyvagal Theory helps us see the body, let 3 Brains Intelligence help us understand it.

Not as a machine.

But as a symphony of intelligences, each with a voice, a need, and a gift to offer.

We are not fragments.

We are whole, integrated beings.

We are meaning-makers. Feelers. Navigators. Learners.

We are Head. We are Heart. We are Gut.

And when all three are aligned, we become unstoppable.