Why Polyvagal Theory Doesn’t Stand Up to the Science

The pseudoscientific framework therapists love to believe

Ah yes, polyvagal theory: The pseudoscientific framework that therapists just love to believe explains their methods of “trauma-informed therapy.”

Only problem is: When the guy behind a scientific theory openly admits that he didn’t propose it to be either proven or falsified, you know you’re not dealing with actual science. 

So the Whole Theory is Bogus?

Let me back up and agree with one truth to be found in polyvagal theory: Being connected to others who make us feel safe, seen, and soothed is of the utmost importance. 

I am also fully behind the physiological fact that slowing down the heart rate calms our body and mind. 

The right people can help us calm down for very specific reasons—just not the ones alleged by the author of the polyvagal theory.

And Now for Some Myth-busting

Back in the ‘90s, a professor named Stephen Porges proposed that one of the nerves coming out of your brain coordinates something called a social engagement system. 

On the surface, it’s a neat idea that seems to explain how your mental health goes awry and how you can get things back in order. 

In search of proof for his point, Porges went down more than a few scientific-sounding rabbit holes of evolutionary physiology. In the end, polyvagal came to mean three basic tenets, which appear here in a summary of how they’re listed on his Polyvagal Institute website:

1. The autonomic nervous system has 3 hierarchical states.
2. The autonomic nervous system, together with a section of the brain, runs a built-in surveillance system that is constantly scanning for and interpreting incoming data.
3. The body has a system for signaling to other people that we are safe or dangerous, and that they can come close or should stay away.

Unfortunately for him, and for everybody who fell prey to this fairytale (which, for several years, included me), none of these tenets are proven by physiological findings or by the latest data on brain function.

Feeling Nervous? Good.

Let’s start with your nervous system.

First, you’ve got your brain and spinal cord, which together are known as the central nervous system. 

Then there’s the somatic nervous system, which contains the nerves to and from your skeletal muscles. 

Finally, there is a system of nerves that go to and from everything that has to work automatically, like your heart, lungs, and viscera, etc., called the autonomic nervous system.

Aaaaaaaaaaand this is where the story goes wonky. 

See, according to physiologists and anatomists who don’t subscribe to the polyvagal idea—the vast majority of these fields—the autonomic nervous system has two states, or “branches.” These states, or branches, are known as the sympathetic branch (active state) and the parasympathetic branch (resting state).

But according to Porges, the autonomic nervous system is a hierarchical 3-state system. At the top of the hierarchy is a “socially-engaged” state called ventral vagal activation. 

Going down, the next state is one of energetic high arousal—aka anxiety—that he says is the state in which all mammals spend their days. Constantly. That is, unless they’re socially engaged, referred to as having their “vagal brake” engaged. 

Finally, at the bottom of the hierarchy there is a state of energetic downregulation, called “dorsal vagal activation.” Per Porges, this is the state where you’re spaced out, depressed, or literally passed out (“dorsal vagal shutdown”).

He then further complicates this 3-state model of a hierarchical nervous system idea by claiming there are also hybrid states, each one combining 2 out of the 3 basic states. These hybrid states of activation purportedly match up to specific psychological experiences such as competition, making love, caring for offspring, and fear.

(As if you could match up every specific psychological experience to a specific physiological state, in every instance and every context—not to mention across culture and language barriers.)

As I mentioned at the top of this blog, Porges credits one of the twelve nerves coming out of your brain with the coordination of his mythical, hierarchical nervous system.

And that nerve is pop psychology’s “it girl” of the moment: the vagus nerve, a giant nerve wandering all over from your upper torso to your lower abdomen. Hence, his terms ventral / dorsal vagal activation.

Porges claims there’s a meaningful evolutionary difference between humans’ vagus nerves and the vagus nerves of other animals. (He’s the lone voice preaching this belief in the vast worldwide landscape of anatomists and physiologists, by the way.)

…Because the evidence he uses to make this claim has been definitively disproved.

Now, on to the fundamentals of 21st-century brain science. Ahem.

Brains are understood to have a single core function: the regulation and coordination of an organism’s internal systems—immune, endocrine, reproductive, and so on. The brain accomplishes this regulation and coordination by anticipating the energy needs of the body’s various organs and systems. Key word being—anticipating —and preparing to meet those needs before they ever arise.

The brain doesn’t react to things out there in the world. The brain runs a model of its body in the world. It simulates reality via something called “predictions,” which are first and foremost, plans for action that are appropriate to your current situation and goals. 

Then (actually, for all intents and purposes, simultaneously), your brain generates some conscious awareness of what it has been doing, (don’t ask how, no one can tell you), and this is what you experience as reality. 

If the “winning prediction” your brain chose turns out to be wrong, it will update and improve its model through something called encoding prediction error (which is just a fancy way of saying “learning”), and on you’ll go with a new winning prediction and experience of reality.

Wait, What?

I’m grazing over a year’s worth of explanations here, but the short story is: There’s a computational theory of brain function that originated in physics and math. It’s called the Free Energy Principle, or the FEP. FEP, translated to the psychological context, is called predictive processing and active inference. I’m hitting just the high points from the deep end of contemporary neuroscience, but long story short: It proves that Porges is wrong.

Let’s start with predictions, in case you’re wondering what they are and where they come from. 

In a nutshell, predictions are the brain’s best guess about what’s happening at the current moment based on what it knows from all your past experiences and what actions would work best to achieve your goals in this moment. 

Predictions make up what is called a “generative model,” which is the sum total of all your prior knowledge. That model allows your brain to conduct the metaphorical symphony that gets the right amount of energy for a situation, in advance of the situation, depending on what the brain thinks the situation is, right to where the body needs that energy to be.

Since Porges is leaning on discredited science to explain brain function, he insists that your brain and nervous system scan for safety and danger.

But, to reiterate, what 21st-century neuroscience says is: The brain is generating your reality IN ADVANCE of the current moment.

In other words, brains don’t take in and experience “reality as it is.” Brains confirm a “reality” they’ve already created inside you by actively searching for “evidence” of that “reality” out in the world. 

Of course, sometimes what’s out in the world doesn’t confirm the internally generated reality. And in this case, one of two things can happen: 

1. The brain ignores that information—and potentially presses on with a delusion or other dysfunctional behavior 
2. The brain updates its model with new information—so it broadens its range of possible predictions

There are many consequences of these two routes that we don’t have time to address here. Here’s the consequence that’s relevant to our topic today:

The notion that we’re always scanning for safety or danger—as if you could define either concept in some concrete, “real” way

AND 

The idea that we’re constantly sending out cues of safety or danger to others 

are scientifically invalid. In other words, they’re wrong… 

Besides being wrong because that’s not how brains work, they’re wrong because if they were correct, it would follow that safety and danger are specific, objective things out in the world. And that would mean that the meanings and manifestations of “safety” and “danger” would be the exact same for every person. 

It should be obvious to everyone reading this that they’re, um, not.

So…

The 3 key principles underpinning polyvagal theory are dead wrong. Wrong. Wrong. WRONG!

Do we need other people to help us calm down? Yes, sometimes we do. In our early lives, we learned to calm ourselves based on our interactions and relationships with other people. 

What if those people weren’t very good at calming us down—let alone calming themselves down? We’ll end up carrying around a pretty poor model for calming ourselves down—and maybe a model of other people as dangerous or unpredictable, too. 

This less-than-optimal outcome is not the result of some imaginary social-engagement “system” up there in your head. It’s a product of the model you’ve constructed about your body in the world, in relationship to other people, and in response to the various uncertainties of life. 

Let’s Be Clear.

It goes without saying that uncertainties about who people are and how they’ll act can energetically arouse us, for sure. 

But, again, that’s not the result of a broken social-engagement system or a faulty ventral vagus nerve. Whenever your brain is faced with something it can’t predict with certainty, your brain will provide you with the extra energy you need to do some learning and enhance your model.

Many people will call that extra energy “anxiety.”  Other people call it excitement. The current, absolutely absurd trend is to call it a “trauma response.” An excess of energy is really nothing more than the activation of a brain state that’s necessary for learning or movement, plain and simple.

Yes, novelty and uncertainty cause nervous-system arousal—usually, so that the body can move, or so that the brain can work on adding to its model. 

Nervous-system arousal doesn’t come from spotting “danger” in the environment. It’s a normal result of normal brain function. No one benefits when nervous-system arousal is pathologized by useless stories about reactive brains that are falling victim to figurative internal systems.

Polyvagal theory doesn’t help you understand what’s actually happening inside of you. It spouts a whole bunch of scientific falsehoods in order to sell training programs and a monetized community. So, buyer beware.

If you’re interested in the real science, check out the Theory of Constructed Emotion and/or information on predictive processing and active inference.