Despite what you may have heard recently, no, the polyvagal theory is not dead.

Hi, I am Justin Sunseri.

I'm a therapist and a member of the Polyvagal Institute's editorial board.

What does that mean?

That means I'm one of a handful of individuals who review other

people's work for Polyvagal Theory accuracy, and it's been a huge part

of this podcast here for years now.

I've gotten a few questions recently from listeners about a new- question mark-

debatably new polyvagal theory criticism.

I dismissed these because they were linking me to third and fourth hand

sources, uh, on Instagram, and I don't take them seriously in all honesty.

But today, one of my, or yesterday as recording this, one of my Untucking

Academy students messaged me with a link to a very popular YouTube

psychology channel that gave us the bad news- the polyvagal theory is dead.

Am I biased?

Yeah, I am.

You can probably hear it in my voice.

I'm a little annoyed by this stuff, but I am much more interested in what's true.

So yeah, I'm biased, but I want truth, or at least as close

to the truth as we can get.

Things need to make sense to me.

None of what I discuss here has anything to do with bias.

Hear out my arguments and decide for yourself.

The writer of the article is Paul Grossman, and the article is called

Why the Polyvagal Theory is Untenable.

I'll put links in the description to that and to other things as well.

Grossman has been a polyvagal theory critic for a very, very long time.

Stephen Porges, the creator of the political theory, has replied to

these criticisms numerous times.

Over the many, many years, he, uh, port has even chatted with me on

my podcast about these criticisms.

I don't mind criticizing people's science, but I don't like to

go on a, a offense where saying people are, are blatantly wrong.

But it's really quite remarkable for over about a 20 year period.

A couple of people were repeatedly misrepresenting the theory and publishing

statements that were creating what is classically called a strawman argument.

He's not shying away from them.

I'm a therapist and even though my knowledge on the topic is

deep, I'm gonna stay in my lane.

I won't address, uh, either of who these two I think is right.

Uh, but I will use critical thinking and simply check Porges' work and that's gonna

tell us a lot and check both their work.

You and I don't need to be experts in the polyvagal theory, actually.

All we need to do is look at the new paper's claims about the polyvagal

theory, and check whether Grossman accurately understands the theory.

If he does not accurately understand the theory, then his counterarguments

are kind of moot, right?

At that point, he's arguing against his own interpretation

and not the theory itself.

This is extremely important.

So they make the false statement, they say, this isn't true.

Well, the theory never said that, and I would agree with them.

That that's not true either, but then they would go on and on with these things.

So let's start from the very beginning of the polyvagal of it all.

The polyvagal theory.

That is the vagal paradox.

This question is what drove the creation of the poly vagal theory.

Understanding the vagal paradox is obviously very important, right?

Or at least for their purposes it is.

Grossman says the vagal paradox often mentioned by Porges- this is a quote-

often mentioned by Porges to indicate that RSA, which is respiratory sinus

arrhythmia, sometimes correlates with changes in cardiac vagal tone

and other times fails to, is not paradoxical at all when RSA is no

longer equated with cardiac vagal tone.

But when RSA is realistically considered as a vulnerable and approximate index

of cardiac vagal tone constrained in its accuracy by many factors.

That sounds good, right?

It's kind of intimidating, lots of fancy words and whatnot.

The only problem is that's not what the vagal paradox is, I'm not gonna

speak for cor uh, Porges, of course.

I'm, I'm simply gonna quote him from his paper called The Vagal Paradox.

He says, how could the vagus be both protective when it was expressed as

RSA and life-threatening when it was expressed as bradycardia and apnea?

Okay, so what's the problem here?

Grossman is fundamentally misidentifying what the vagal paradox actually is.

Grossman reframes the vagal paradox as a measurement problem.

He is essentially arguing that it's just a methodological limitation of

RSA as an index of cardiac vagal tone.

In his framing, there's no real paradox, just, um, an imprecise uh, measuring tool.

The RSA is a measuring tool.

But that's not the paradox that Porges identified.

The actual vagal paradox, as Porges articulated it is a

question about neurobiology.

How the same nerve, the vagus, how it can be both life sustaining when expressed

as RSA, which indicates healthy, uh, vagal tone and resilience, how it can

be life sustaining and life threatening when it's expressed as bradycardia and

apnea, which can kill a preterm infant.

These are two completely different questions.

I'll try to reword it one more time.

Grossman's version is- is RSA good enough ruler for measuring vagal tone?

Porges' actual version is, Why does the same nerve produce

opposite survival outcomes?

The vagal paradox drove porges to investigate the brainstem and to

ultimately discover that there are two anatomically distinct vagal

pathways originating from different brainstem nuclei with fundamentally

different functions, uh, but both of which utilize the vagus nerve.

A personal thought- and I find it very, very odd that Grossman did not include

a direct quote from Porges in this critique paper about the vagal paradox.

It took me 30 seconds.

It's really not hard.

Porges has a paper called The Vagal Paradox.

I imagine if Grossman had maybe reread that paper, he would've

realized that he misunderstood.

I I, I would hope.

I also find it odd that Grossman dismisses Porges' question about RSA

and bradycardia in the vagal paradox.

The polyvagal theory hypothesizes that the vagus nerve serves as the

highway four, two heart rate- heart rate influences- ventral and dorsal.

That's the theory derived from the vagal paradox.

Why does Grossman ignore the bradycardia piece of this in his

definition of the vagal paradox?

He didn't mention it at all.

Either he doesn't get it or he's ignoring it.

Remember, Grossman is responding to Porges' vagal paradox question.

Grossman does not have his own vagal paradox as, as best I can tell.

So to respond to Porges' vagal paradox question, Grossman needs

to accurately understand it, right?

So why doesn't he accurately express Porges vagal paradox

to set up his rebuttal?

Either again, either he doesn't get it or he is ignoring it.

And another reminder, Porges has responded to this guy numerous times.

There is no excuse for this misunderstanding.

I actually did a super easy, and this is something I knew just because I'm

familiar with both of them, but I took it to another level and I did a really

easy experiment that you can do yourself.

So go to Grossman's paper, download it, and then go to

Porges' paper and download it.

I'll put a link in the description for both of them.

Then upload them to a non-biased ai.

I used Google Notebook, lm, which is amazing at using sources and has a

huge context for exactly this purpose.

And then I asked it to give me the definitions from Grossman and Porges.

And guess what?

It define- the AI- defines Porges definition as protection versus

threat, and Grossman's definition as a measurement misunderstanding.

You could do this little experiment yourself with any questions you

have about their work, how it is misaligned, just trying to understand

it better, who misunderstands what?

Don't taint the ai.

Just ask it objective questions and it'll tell you to give, ask it to give

it to you at like a fifth grade level.

Um, RSA is not essential to the polyvagal theory.

That's what we're moving on to next.

Grossman spends a lot of time on RSA.

In this paper.

He treats RSA as a foundational construct of the polyvagal theory.

Basically, if he can break down the RSA argument, then the theory crumbles,

I think is what he is getting at.

However, Porges said in his 22, 20 23 paper that quote, RSA is a portal

to the function of the ventral vagus enabling the testing of polyvagal

informed hypotheses, but is not a foundational construct of the theory.

Porges uses RSA as a potential measurement of something very specific.

Very specific.

If that does, that measurement doesn't work out, it doesn't.

It doesn't mean that the entire theory is untenable.

Think of it this way.

Let's say you hypothesized that the temperature of someone's forehead

correlates with how sick they are.

You use a thermometer as your measurement tool.

Now, somebody comes along and says that thermometer is not perfectly accurate.

It gives inconsistent readings depending on ambient temperature

and sweat and skin tone.

Therefore, the concept of illness is untenable.

That sounds absurd, right?

The thermometer is just one portal- potential- into detecting something real.

Attacking the instrument doesn't dissolve the underlying phenomenon.

That's exactly what Grossman is doing with RSA.

RSA is Porges' thermometer- a portal has his own word into

detecting ventral vagal activity.

It is a useful, testable, measurable, repeatable window into something

that the theory proposes is real.

But Polyvagal Theory does not stand or fall on whether RSA is a

perfect index of cardiac vagal tone.

The theories, foundational constructs are neuro anatomical and evolutionary.

Existence of two distinct vagal pathways, the evolutionary hierarchy

of the autonomic nervous system, and the adaptive functions of each circuit.

Those claims live in the brainstem, not in a heart rate variability graph.

So when Grossman dedicates really substantial effort to dismantling

RSA as a reliable measure.

He's essentially arguing that the thermometer is flawed and

concluding that fever does not exist.

Again, I don't understand why Grossman would go to such effort

to dismantle RSA when Porges said that it's not central to his theory.

Either he doesn't get it or is ignoring it.

He read the same 2023 paper that I did.

He cites it.

In his article, there's no reason for this.

Let's talk about, uh, freeze and shutdown.

This is the third, um, issue I'll tackle.

Listeners of this podcast will know very well the difference between

freeze and shutdown, but for those who might be new to this channel, freeze

and shutdown are not the same thing.

They both involve, uh, immobility, yes.

And are, you know, autonomically driven.

But shutdown is a limp collapse and freeze is a tense paralysis.

Shutdown would be like playing dead and falling to the floor.

Freeze is like a panic attack.

It's tense.

In the polyvagal theory, shutdown is a dorsal vagal response.

Freeze is a dorsal vagal response, plus sympathetic flight fight.

Grossman confuses the two, and actually, I, I don't even blame him, uh, entirely

for this because Porges' language on the subject was, was very confusing,

um, in his like primary documents.

His, uh, writings.

I asked him about this during my first interview with him way, way,

way back in episode 15, and he, he did clarify the distinction.

So there, there's this whole ambiguity because people use the word freeze

when they really mean shutting down.

Okay?

So the mouse in the jaws of a cat is not frozen, it's just, it just limp.

And that is clearly the limp loss of muscle tone is a dorsal vagal response.

The rigidity is much more- let's say, okay mixed or complex.

Porges says that bradycardia reflects dorsal vagal

influence, uh, as a measurement.

Bradycardia is a significantly slower heartbeat, which

is, uh, potentially fatal.

In shut down, a dorsal vagal response, we would expect to see bradycardia.

We would expect to see a massive drop in heart rate, just like Porges

saw in the preterm neonatal unit that prompted the vagal paradox.

But what about freeze?

Would we expect to see a massive drop in heart rate during a freeze?

Again, freeze is the combination of immobility and mobility.

Shut down, plus flight fight.

Dorsal plus sympathetic, both pathways are active.

At the same time.

Freeze can look like a panic attack or scared stiff or tonic immobility.

So outwardly it's immobile, but internally there's a high level of

activation including a higher heart rate.

So, no, I don't- we would not expect to see bradycardia and freeze, I don't think.

Grossman does not understand this and argues that there

is no bradycardia in freeze.

I assume Porges' response would be, "Yeah. No kidding."

Next topic.

Non mammals and myelinated nerves that affect heart rate.

Grossman points to extensive research showing that non mammal mammalian

species such as sharks and fish and reptiles also possessed- possess fast

acting myelinated nerves and can use them to instantly change their heart

rate in response to their environment.

From Grossman's perspective, because this hardware exists throughout the

vertebrate vertebrate family tree, it cannot be a special mammalian innovation

for social engagement, as Porges suggests.

But this is not a Polyvagal Theory proposition.

Porges has already clarified that polyvagal theory does not rely

on mammals being the only ones with fast acting nerves uh, that,

you know, slow down heart rate.

It doesn't matter if non mammals can slow their heart with

fast acting myelinated nerves.

It doesn't matter.

In- instead- instead, polyvagal theory focuses on the brainstem

regions where those nerves originate.

Porges argues that in mammals, these nerves underwent an evolutionary,

uh, ventral migration to the front of the brainstem, moving from the dorsal

motor nucleus to the nucleus ambiguous.

This shift is critical because it places the heart's, uh, braking system

right next to the nerves that control the face, voice, and listening.

So this brings us to the next issue, which is Grossman's, um,

misunderstanding about social behavior.

He says, or he points out that modern reptiles are far from asocial creatures.

They exhibit complex behaviors such as long-term pair bonding, communal

parenting, and social learning, which actually was really interesting.

I didn't- I'm not aware of these things.

But in response, poor just says that's, that's cool about the

reptiles, but it's also entirely irrelevant to the polyvagal theory,

which he describes as mammal centric.

He clarifies that polyvagal theory is interested in the specific evolutionary

transition from ancient, extinct common ancestors to mammals, not the

separate path that modern reptiles took.

The sociality of modern reptiles is irrelevant.

Mammals have a unique social engagement system according to the polyvagal theory.

This system integrates heart regulation with, uh, facial expressions and voice

giving mammals the ability to use social cues like a, a warm voice, gentle eye

contact, eye crinkles, or smiling to help calm each other and to indicate safety.

This is called co-regulation.

Porges' Social engagement system- co-regulation- is not the same,

I don't think as Grossman's social behaviors in reptiles.

I mean, just think about it for a second.

When was the last time you saw iguana smiling with each other or heard a snake

Singing to their young to calm them?

How about two frogs embracing closely in the moonlight?

Grossman does not accurately reflect Porges social engagement system.

These are not the same thing.

The sociality he's discussing is obviously different.

I don't know why he bothers making the distinction and

it's, it's not the same thing.

So I'll wrap it up, um, here-ish.

Um, gross men and friends have more to say.

I assume Porges is gonna respond yet again, but honestly, if

he doesn't, I don't blame him.

Hey, this is editing Justin.

I was looking into more of, uh, what Grossman was saying, and, um, I found

that, uh, Porges has already released a rebuttal to, so I wasn't even aware of it.

I'll have to read through that.

So everything that I've talked about.

And everything that I have on the YouTube video, the citations that

are, the quotes that I've put up on the screen, there may be even better

arguments that I haven't got into yet.

So I can't wait to read that.

Back to the podcast.

Grossman is recycling the same talking points he has harped on for years on

ResearchGate to the general public, begging for others to interact with

him, to respond to him, to debate him.

No, I am not exaggerating.

Read it for yourself.

I will of course, give you a link in the description to,

uh, Grossman's Research Gate.

Did Grossman collect a few dozen others to edit and sign this paper?

Yeah.

And that's something.

But the paper largely doesn't address what the polyvagal theory actually says.

So I, I don't know what that's worth.

Scientists get things wrong.

It has happened throughout history, especially when new ideas that

contradict traditional, uh, understandings and status quo surface

and scientific debate is totally fine.

But one thing really sticks out to me about this specific

paper from Grossman and Friends.

It seems to be written with a psychological bent.

It doesn't seem to be written for the science crowd, exactly.

I mean, it is kind of because it uses all the science terminology,

but it also singles out people like me who use the theory to better

understand and help my clients.

The paper starts off addressing people like me in the abstract

and in the introduction as well.

It seems pretty clear to me that this is who it's written for.

It doesn't seem to be written for Dr. Porges.

There are no new arguments there for him to rebut.

It seems like the same stuff over and over again.

It's written for mental health service providers, which

I find really interesting.

The last three of the 12 conclusions are about psychology

and treatment, and encourage people like me to look elsewhere; to

disregard the polyvagal theory.

What's sad is that it seems to have worked.

Therapists and psychologists and the like seem to be responding, abandoning

the theory except for the stuff that they like, like the states and and

co-regulation, because Grossman's paper seems scary and like he gets

the theory and has counterarguments and a few dozen people who agree.

Therapists, even popular YouTube therapists and Instagram

therapy influencers are not spending the time to examine it.

And I don't blame them either.

It's, it's really difficult.

It's very dense.

And to read to people who disagree, it's not easy.

So I don't, I don't blame them, but you know, mostly I don't blame them.

A lot of what I pointed out here just requires a smidge of

research and critical thinking.

It's really not that hard.

You don't have to be an expert in neuroanatomy to say, this dude does not

understand what this other dude is saying.

And you really don't need to be an expert in 2026 to upload two

scientific papers into an unbiased AI and then to ask your own questions.

I think it's actually a really good idea.

Now, does any of this mean that I know for certain, um, that

what Dr. Porges says is true?

No.

No, it doesn't.

But what he, and I'm, I'm, I'm a lay person- but what he writes about makes

sense to me and it's made more sense in the psychology realm than anything

else I've learned about, honestly.

And it's not a modality, it's the science that kind of contributes

to the way we think about things.

The serious criticism of the polyvagal theory, which really

all come from Grossman, who cites someone named Taylor all the time-

it, it really doesn't measure up.

And so I hope you can see, um, that from just this one video, I don't

think I'll continue commenting on this.

Um.

I don't really have much more to say about it.

So if people are gonna have follow up questions, I would recommend you

read Dr. Porges' direct response to Gro- responses, plural to Grossman.

Um, that would be the best place to go.

Anyhow, I appreciate you watching all the way to the end.

You obviously take this stuff seriously and I'm glad to be in your company.

I think the Polyvagal Theory bandwagon is disappearing, and I love it.

Bye.