The short version
- What it is: polyvagal theory, proposed by psychophysiologist Stephen Porges in 1994, says your vagus nerve runs two separate circuits: a newer "ventral" one for calm and connection, and an older "dorsal" one for shutdown. It's where "ventral vagal," "dorsal vagal shutdown" and the traffic-light language come from.
- What's disputed: the anatomy and evolution underneath. Critics have argued since 2007 that its heart-rhythm measure isn't a clean gauge of vagal activity and its evolutionary story doesn't fit other animals.
- The 2026 paper: 39 researchers led by Paul Grossman called the theory "untenable." Porges replied in the same issue that they had attacked a version of the theory he never proposed.
- What holds up: your vagus nerve really does slow your heart on the out-breath, slow breathing really does raise vagus-linked HRV, and even the critics say body-based therapies often help on their own.
- What it means for you: keep the traffic light as a way to describe how you feel. Be wary of anyone who says they can measure your "state" or sells you a fix for it.
Two posts in a row
It's ten past one, you're eating a sandwich at your desk, and Instagram serves you two posts back to back. The first, in soft beige, says the bone-deep flatness you've had since February is "dorsal vagal shutdown," your nervous system protecting you. It's the first explanation that hasn't made you sound lazy. The second, from a science account, says polyvagal theory has been debunked.
So were you wrong to find the first one comforting?
Not really. This is a genuine argument between serious researchers, and it's mostly about the wiring diagram, not about whether you feel what you feel.
What polyvagal theory says
Porges first presented the theory in his 1994 presidential address to the Society for Psychophysiological Research and published it in 1995. In plain English, it makes six claims:
- Two vagal circuits. The vagus fibers that reach your heart start in two brainstem areas. The "ventral" branch, from the nucleus ambiguus, is myelinated (insulated, so fast). The "dorsal" branch, from the dorsal motor nucleus, is unmyelinated and older.
- An evolutionary ladder. Porges ranks three circuits by age: dorsal shutdown, shared with most vertebrates; fight or flight; and the ventral system, which he describes as mammalian. Under threat you try the newest first and drop down a rung when it fails.
- Neuroception. Your nervous system scans for safety and danger below conscious awareness, which Porges distinguishes from perception.
- The social engagement system. The ventral circuit is linked with the muscles of your face, voice and listening, so feeling calm and feeling connected travel together.
- RSA as a gauge. Respiratory sinus arrhythmia, your heart rate rising as you breathe in and falling as you breathe out, is proposed as a readout of the ventral circuit.
- Dorsal shutdown. When fighting or fleeing won't work, the oldest circuit takes over: immobility, fainting, playing dead.
The traffic light maps neatly onto this. Green is ventral, red is fight or flight, blue is dorsal shutdown.
What's disputed
The pushback isn't new. In 2007, Grossman and physiologist Edwin Taylor reviewed RSA in Biological Psychology. They agreed it often tracks vagal activity within one person, but said breathing patterns, physical activity and other factors can pull the two apart, and comparisons between people are shaky. They also traced heart-breathing coordination back to fish. Porges replied that year that they had misrepresented the theory, which he said never claimed only mammals link breathing and heart rate.
In 2023, Grossman went further in the same journal. He argued that nearly all five of the theory's core premises rest on RSA, that treating RSA as vagal tone is a category mistake, and that each premise is either untenable or highly implausible.
The 2026 paper
In February 2026, Clinical Neuropsychiatry published a commentary by Grossman and 38 co-authors, specialists in autonomic physiology, vagal function and animal behavior. It responded to Porges's 2025 review in the same journal, and its title calls the theory "untenable." Their main points, paraphrased:
- The big heart slowdowns come from the "ventral" branch. In mammals, they say, the nucleus ambiguus drives most heart-rate changes, including large drops; the dorsal motor nucleus contributes modestly, if at all. So the branch the theory files under calm and connection is also the one behind the dramatic slowing.
- Freezing doesn't look the way the theory predicts. In people, emotional freezing and dissociation don't typically bring big drops in heart rate; it usually stays the same or dips slightly. They call dorsal vagal shutdown "wholly untenable."
- RSA isn't a direct gauge. It only sometimes tracks the vagal signal to the heart, they say, and links between people are often weak.
- The evolution doesn't fit. Fish, amphibians, reptiles and birds have fast, myelinated vagal fibers too. Breathing-linked heart-rate changes appear in animals as distant as the dogfish, a small shark. Reptiles and birds pair-bond, raise young and hunt together, so social behavior isn't a mammals-only feature.
- The psychology came first. Ideas like safety, connection and co-regulation predate the theory, and the authors say body and mind therapies often may help on their own.
- Clinical use. Because the theory is widely taught as established, they argue, using it to guide treatment of vulnerable groups is "neither scientifically valid nor ethically acceptable."
Porges's reply
Porges answered in the same issue with a paper titled, pointedly, "When A Critique Becomes Untenable." His central charge is that the critics attacked a "reconstructed proxy" of the theory, a straw man built from claims it doesn't make.
- On RSA, he says it indexes one specific pathway, and the breathing link critics treat as noise is the signal itself.
- On shutdown, he describes it as a shift in which circuit dominates, not the dorsal branch switching everything off, and says the dorsal state isn't inherently a problem.
- On evolution, he says vagal features in non-mammals are expected and don't threaten the theory.
He argues the disagreements are about measurement and framing, which isn't disproof, and lists results that would count against the theory. He says it remains open to revision, and calls the critics a self-selected group, many with earlier critiques on record.
Neither paper is a new experiment. Both argue over existing evidence, written by people with long histories in this fight, and Porges is defending his life's work, including a listening program built on it. My read: the anatomy behind "dorsal vagal shutdown" is under the most pressure, and Porges's own description of shutdown is more modest than "your dorsal vagus has taken over." Nobody disputes that the numb, can't-move feeling is real.
Why it's everywhere anyway
The 2026 critics themselves call it one of the most popular frameworks in psychotherapy. Much of that came through therapist Deb Dana, whose 2018 book The Polyvagal Theory in Therapy, with a foreword by Porges, translated it for clinicians and popularized "glimmers," small cues of safety. The Polyvagal Institute, which Porges co-founded, runs a certificate course for becoming a "polyvagal-informed" professional.
It also names things people struggled to explain: why you can feel numb rather than anxious, why "just relax" doesn't work. That's a lot of relief from one diagram.
What we couldn't find is a randomized trial testing polyvagal-informed therapy against any other therapy. A randomized trial of Porges's own listening program, the Safe and Sound Protocol, against ordinary music is registered, but it hadn't started recruiting when we checked in October 2026.
What still holds up
Strip away the contested anatomy and plenty is left standing.
- The exhale brake is real. Your heart speeds up slightly as you breathe in and slows as you breathe out, largely through the vagus nerve. The argument is about how much that rhythm can tell you, not whether it exists.
- Slow breathing works on it. A 2022 review of 223 studies found slow breathing raises vagus-linked heart rate variability during practice, straight after, and over weeks.
- Calming practices have their own evidence. A 2023 meta-analysis of 12 trials (785 adults) found breathwork modestly lowered stress, and a 2017 meta-analysis of 24 studies (484 people) found a large effect of HRV biofeedback on self-reported stress and anxiety. None of that depends on polyvagal theory being right.
- The states are real. Wired, flat, safe with someone: these are experiences, not anatomy claims.
Our page on the Science calls polyvagal theory a useful map, with an asterisk. After 2026 the asterisk is bigger. The map still works as a map.
How to use the language without being sold to
- Treat the traffic light as weather, not wiring. "I'm in blue today" is a useful description. "My dorsal vagal complex has taken over" is a claim about anatomy that specialists are actively fighting over.
- Be skeptical of anything that says it can measure your state. No phone camera or quiz can tell which brainstem branch of your vagus is in charge; researchers can't agree on that in a lab. NEUROFIT sorts you into six states named after the theory, with no mention that its core claims are disputed (our NEUROFIT review). BrainTap's blog asks whether your nervous system is "dysregulated," then offers a free trial of its headset (our BrainTap review).
- Notice when a book calls it "the science." The Vagus Nerve Reset has a chapter called "Polyvagal Theory: The New Nervous System." Its practices are sensible; its framing is more certain than the field (our review of the book).
- Ask your therapist what you're actually doing. If the language helps you in therapy, keep it. The useful question is what the practice is: slower breathing, pacing, grounding, time with safe people. Those stand on their own. If trauma or dissociation is part of your story, the critics' concern about vulnerable groups is worth raising with them.
- Start free. Slow breathing, a walk, cold water on your face: the Analogs covers the low-tech tools that don't depend on anyone's diagram.
FAQ
Is polyvagal theory debunked?
"Debunked" overstates it. In 2026, 39 researchers called the theory "untenable" on physiological and evolutionary grounds, and Porges replied that they had attacked claims it doesn't make. The anatomy is seriously contested; the experiences it describes are not.
What is dorsal vagal shutdown?
It's polyvagal theory's name for a freeze or collapse state: numb, foggy, flat, sometimes faint. The theory pins it on the older, unmyelinated branch of the vagus. The 2026 critics say human freezing doesn't show the heart slowing that would require. The feeling is real; the explanation is disputed.
Is polyvagal theory pseudoscience?
Pseudoscience usually means claims that can't be tested. Polyvagal theory came from a research scientist, appeared in peer-reviewed journals, and both sides treat it as testable. The fight is over whether it passes, and critics object that it's taught as settled when key parts appear to fail.
Is the polyvagal traffic light still useful?
For many people, yes, as a way to notice and name how you feel. Treat it as a description, not a diagnosis, and be cautious with products that claim to read or fix your state.
The bottom line
Polyvagal theory is in a real scientific fight, and the anatomy at its center has taken serious hits, though its creator says they landed on a theory he never proposed. You don't have to pick a side to use what's useful. The traffic light is a decent way to notice your state, and the slow exhale is a well-evidenced way to change it. I'd keep both and hold the wiring diagram loosely.
Your body didn't need a theory to feel what it feels. It just needed taking seriously.
This article is for information, not medical advice.
Some links on this site may earn us a commission. That never changes what we report.
Sources
- Porges SW. "Orienting in a defensive world: Mammalian modifications of our evolutionary heritage. A Polyvagal Theory." Psychophysiology 32:301-318 (1995), from his 1994 presidential address: Porges's reprint page
- Porges SW. "The polyvagal theory: New insights into adaptive reactions of the autonomic nervous system." Cleveland Clinic Journal of Medicine 76(Suppl 2):S86-S90 (2009): PMC
- Grossman P, Taylor EW. "Toward understanding respiratory sinus arrhythmia: Relations to cardiac vagal tone, evolution and biobehavioral functions." Biological Psychology 74(2):263-285 (2007): doi.org
- Porges SW. "A phylogenetic journey through the vague and ambiguous Xth cranial nerve." Biological Psychology 74(2):301-307 (2007): PMC
- Grossman P. "Fundamental challenges and likely refutations of the five basic premises of the polyvagal theory." Biological Psychology 180:108589 (2023): PubMed
- Grossman P, et al. "Why The Polyvagal Theory Is Untenable: An international expert evaluation of the polyvagal theory and commentary upon Porges, S.W. (2025)." Clinical Neuropsychiatry 23(1):100-112 (2026): PMC
- Porges SW. "When A Critique Becomes Untenable: A Scholarly Response To Grossman Et Al.'s Evaluation Of Polyvagal Theory." Clinical Neuropsychiatry 23(1):113-128 (2026): PMC
- Dana D. The Polyvagal Theory in Therapy: Engaging the Rhythm of Regulation. W. W. Norton (2018): British Library record; author page: rhythmofregulation.com
- Safe and Sound Protocol randomized trial registration, NCT06701578: ClinicalTrials.gov
- Shaffer F, Ginsberg JP. "An Overview of Heart Rate Variability Metrics and Norms." Frontiers in Public Health 5:258 (2017): PMC
- Laborde S, et al. "Effects of voluntary slow breathing on heart rate and heart rate variability: A systematic review and a meta-analysis." Neuroscience and Biobehavioral Reviews 138:104711 (2022): PubMed
- Fincham GW, et al. "Effect of breathwork on stress and mental health: A meta-analysis of randomised-controlled trials." Scientific Reports 13:432 (2023): PMC
- Goessl VC, Curtiss JE, Hofmann SG. "The effect of heart rate variability biofeedback training on stress and anxiety: a meta-analysis." Psychological Medicine 47(15):2578-2586 (2017): doi.org