Polyvagal Theory: Untenable, Debunked, or Misunderstood?
In February 2026, a group of 39 researchers published a paper (Why The Polyvagal Theory Is Untenable: An international expert evaluation of the polyvagal theory and commentary upon Porges, S.W. (2025). Polyvagal theory: current status, clinical applications, and future directions. Clin. Neuropsychiatry, 22(3), 169-184) calling polyvagal theory "untenable." But "untenable" targets the theory's physiological mechanisms, not its clinical tools. The breathing, co-regulation, and somatic practices it inspired still have independent evidence behind them. Polyvagal theory has not been debunked; its scientific foundations are being debated.
Polyvagal theory has shaped how many therapists understand trauma for nearly three decades. So when the paper declared it "untenable," the response was swift and noisy. Headlines announced the theory had been "debunked." Social media amplified the verdict. For clinicians and clients who rely on polyvagal-informed approaches, it felt like the ground had shifted. But the story is more nuanced than the headlines suggest. The critique raises real scientific questions, yet it doesn't dismantle the clinical practices built around the theory. This post breaks down what the critics actually argue, how leading clinicians have responded, and what the debate means for people working with trauma today.
What does polyvagal theory actually claim?
Stephen Porges developed the polyvagal theory in the 1990s. He proposed that the autonomic nervous system is more complex than the classic two-branch model of sympathetic and parasympathetic activity suggested.
According to Porges, the system works in a hierarchy of three states:
Ventral vagal: supports social engagement and a felt sense of safety.
Sympathetic: drives fight-or-flight responses.
Dorsal vagal: triggers shutdown, freeze, collapse, and dissociation.
The theory also introduced neuroception, the nervous system's continuous, below-conscious scanning for cues of safety or threat.
These ideas gave clinicians something they had long needed: a neurobiological story for why trauma survivors get stuck in dysregulated states, why "irrational" reactions to safe situations make sense, and why the therapeutic relationship itself acts as a regulating environment.
Dr. Porges is a Distinguished University Scientist at Indiana University's Kinsey Institute, a Professor of Psychiatry at the University of North Carolina, and the author of more than 400 peer-reviewed publications. His 1969 paper was the first to link heart rate variability with autonomic function, foundational work behind the biometric tracking in devices like the Oura Ring and Apple Watch.
What does the 2026 critique argue?
The paper, "The Polyvagal Theory Is Untenable," was authored by 39 researchers, including neurophysiologists, evolutionary biologists, and autonomic scientists, led by Paul Grossman. It targets the neurophysiological and evolutionary foundations of the theory, not its clinical applications.
The critics make three core arguments:
The evidence for polyvagal theory's evolutionary claims is weak.
The anatomical distinctions Porges draws between ventral and dorsal vagal pathways are not as clean as the theory requires.
Respiratory sinus arrhythmia (RSA), the key measurement the theory uses as a proxy for vagal tone, is not reliable across different physiological conditions.
In plain terms, the specific neurological architecture the theory depends on may not work exactly the way Porges describes. These are legitimate scientific critiques, and they deserve serious engagement.
There's also important history here. Versions of these criticisms have circulated in the peer-reviewed literature since at least 2007, when Grossman and Taylor first questioned aspects of the theory. Porges has responded to each iteration, including this latest paper. That ongoing back-and-forth isn't a sign of a theory in collapse; it's science doing its job.
Has polyvagal theory been "debunked"?
No. And this is the distinction that matters most.
When scientists call a theory "untenable," they mean something precise: the mechanistic claims aren't adequately supported by current evidence and need to be revised, refined, or abandoned. That is categorically different from saying everything built on the framework is worthless. Conflating the two causes real harm, to practitioners, to the field, and most of all to the people in treatment.
The history of aspirin offers a useful parallel. For decades, doctors prescribed aspirin for pain, fever, and inflammation without understanding how it worked. It wasn't until the early 1970s that John Vane discovered how aspirin inhibits the COX enzyme, work that won him the Nobel Prize in 1982. The medicine was never in doubt. Only the explanation was missing. A gap in the science did not create a gap in the treatment.
Polyvagal-informed practice works much the same way. There is solid evidence that extended exhale breathing reduces physiological arousal. Social connection and co-regulation lower sympathetic activation. Rhythmic movement, humming, and prosodic vocalisation all shift autonomic state. None of these findings depends on polyvagal theory being mechanistically correct. They stand on their own.
What the theory provided was an organising framework, a coherent story that helped clinicians understand why these interventions help, and helped clients understand that their trauma responses were not failures of will or character.
How have clinicians responded to the critique?
Clinical psychologist Dr Arielle Schwartz, who has spent 25 years applying interpersonal neurobiology in psychotherapy, offers a measured defence. She argues that the central clinical proposition of polyvagal theory, that autonomic state functions as an organising platform shaping perception, emotion, and relational behaviour, was not empirically disproven by Grossman and colleagues. In her view, parts of the critique address a reconstructed version of the theory rather than its stated principles. As she puts it, distinguishing between disagreement over mechanisms and refutation of core propositions is essential for an informed evaluation.
Schwartz also highlights what polyvagal theory uniquely offers: the relational context of regulation. Other vagal models, such as the neurovisceral integration model (Thayer & Lane, 2000) or vagal tank theory (Laborde et al., 2018), tend to treat regulation as a closed circuit within the individual. Polyvagal theory frames the nervous system as an open circuit, shaped by cues of safety and danger in our social environment. As she invokes the poet John Donne, "no man is an island."
She raises one more point worth sitting with. While Grossman and colleagues question the scientific basis of the theory, they do not propose an alternative explanation for the so-called paradox of the parasympathetic nervous system, why the vagus nerve can produce both a calming "rest and digest" response and a shutdown, faint, or freeze response. Polyvagal theory remains one coherent model for that clinical puzzle.
What does this mean for trauma treatment?
For practitioners and clients, the practical takeaway is reassuring. The interventions that grew from polyvagal-informed work, somatic approaches to trauma, titrated exposure, paced breathing, and attention to the regulating role of the therapeutic relationship have documented efficacy that doesn't rise or fall with the mechanistic debate.
These approaches have been applied across trauma treatment, chronic pain, functional neurological disorders, paediatric care, and educational settings, with consistent reports of symptom reduction and improved regulation.
Good science is iterative. Theories are proposed, tested, challenged, and refined. Porges himself has updated polyvagal theory several times in response to critique, and the current debate is live and unresolved. The 39 authors are not the final word.
Practitioners can hold two truths at once. Some specific neurophysiological claims of polyvagal theory are genuinely contested, and that debate belongs in the scientific literature. At the same time, the clinical framework, the language of safety and dysregulation, and the interventions it inspired continue to have documented value. Discarding them over a mechanistic dispute wouldn't be evidence-based practice; it would be an overcorrection with real costs for real people.
Where the debate stands now
Polyvagal theory sits in an interesting place: its mechanisms are under serious scientific scrutiny, while its clinical applications remain widely used and supported by independent evidence. "Untenable" is a claim about the former, not the latter. "Debunked" overstates both. If you want to form your own view, read the primary sources together: Grossman et al.'s 2026 critique, Porges's published response ("When a Critique Becomes Untenable"), and the Polyvagal Institute's overview addressing common criticisms. Reading them side by side helps separate genuine scientific debate from claims that the theory's core has collapsed. For clinicians and clients, the most grounded position is also the simplest. The nervous system is real. Dysregulation is real. The need for safety is real. However, this debate resolves, none of that changes.
Frequently asked questions
Is polyvagal theory still useful for therapists?
Yes. The clinical tools associated with polyvagal theory, paced breathing, co-regulation, somatic trauma work, and attention to the therapeutic relationship have documented efficacy that doesn't depend on the theory's contested mechanisms. Many therapists continue to find the framework valuable for explaining trauma responses to clients.
What's the difference between "untenable" and "debunked"?
"Untenable" means the theory's mechanistic claims aren't adequately supported by current evidence and need revision or refinement. "Debunked" implies that everything built on the theory is invalid. The 2026 critique makes the first claim, not the second, so describing the theory as "debunked" overstates the case.
Who wrote the 2026 critique of polyvagal theory?
The paper, "The Polyvagal Theory Is Untenable," was authored by 39 researchers led by Paul Grossman, including neurophysiologists, evolutionary biologists, and autonomic scientists. It was published in Clinical Neuropsychiatry as a commentary on Porges's 2025 paper.
What is respiratory sinus arrhythmia, and why does it matter to the debate?
Respiratory sinus arrhythmia (RSA) is the natural variation in heart rate that occurs with breathing. Polyvagal theory uses it as a proxy for vagal tone. The critics argue RSA is not a reliable measure across different physiological conditions, which is one of their central objections to the theory's foundations.
Should clients stop using polyvagal-informed therapy?
There's no evidence-based reason to. The scientific debate concerns the theory's underlying mechanisms, not the safety or effectiveness of the practices. Abandoning helpful interventions over a mechanistic dispute would be an overcorrection that could harm people who benefit from them.