Polyvagal Theory: How Your Nervous System Keeps You Safe

Polyvagal theory is really helpful for understanding the relationship between the body, the mind, the nervous system, and trauma. It's a theory that guides my work as a therapist and as a mindfulness teacher. I wrote my thesis on polyvagal theory, depression, and mindfulness.

It's all about regulation: how, through trauma, our body and our nervous system become dysregulated, and how healing supports the regulation of the nervous system.

What is polyvagal theory?

Polyvagal theory was proposed by a neuroscientist called Stephen Porges in 1994, and it's about how your nervous system keeps you safe. If there's danger, the nervous system responds by moving you into safety. If there's safety, it goes into a rest and digest state, where you can really recover, be in relationship, and feel connected.

Porges calls this checking neuroception. Your body is always checking, without you noticing, whether you're safe, whether there's danger, or whether there's serious threat. Depending on what it finds, it moves you into one of three states.

1. Safe: the social nervous system

When the environment is safe, our nervous system goes into what Porges called the social nervous system. This is the ventral branch of the vagus nerve, and it's all about being in relationship.

Our whole body relaxes: our stomach relaxes, our breathing relaxes. Our voice is able to go up and down. The muscles in our face are soft, and we can smile. We communicate that we are safe to be around, and other people mirror that back to us.

Our thoughts change too. They're more social, friendly, kind, non-judgmental. This is where the crossover with mindfulness is really valuable. If you think of mindfulness as non-judgmental, open, kind, present awareness, that's very much the social nervous system. We're naturally in that space when our nervous system feels safe.

2. Danger: fight and flight

When we're threatened, we engage the sympathetic nervous system and move into fight and flight. Our faces tighten. Our voice becomes much flatter, almost like growling. Our posture shifts, we make fists with our hands, and others experience us as threatening.

And it changes how we think. Our emotions move towards fear, anxiety, worry. Our mind becomes much more judgmental. We're scanning the environment: "Here is where the danger is. That's where the safety is. Let me go there." In a way, it's the opposite of mindfulness.

3. Inescapable danger: shutdown and freeze

When the environment is so dangerous that there's nothing we can do, when we cannot escape, we go into a shutdown response: immobilization. This is the dorsal branch of the vagus nerve. We feel numb, heavy, switched off. We dissociate. The lights are on, but nobody's home.

It may not seem like it, but this is a survival response too. Think of a little mouse running through a valley when an eagle flies over the top. The mouse completely freezes. It doesn't even move its ribs, because the slightest movement will be detected by that eagle.

So all three are survival states. The social nervous system is safety in numbers, safety in community. Fight and flight is for when the threat is, let's say, medium. And shutdown is for when the threat is overwhelming. None of this is decided by the conscious mind. It happens unconsciously.

Freeze is not weakness

People often don't understand freeze as part of the survival system. In fact, it's sometimes used as a defense by lawyers when their client is being prosecuted for rape: "The person didn't fight my client off, so it can't be rape."

But when we understand the nervous system, we understand that the person may have been in such an experience of threat that they went into shutdown, as a way to survive. It's not because they're weak. It's because their nervous system made an unconscious decision to put them in that freeze response.

When the system becomes faulty: trauma

Trauma plays a big role in all of this. The system can become faulty, so that when there's safety, we behave as if we're in danger, or when there's danger, we behave as if we're safe.

You might notice this yourself. Your nervous system has become tuned in certain ways. Maybe you're in a conflict that isn't such a big deal, and you shut down. Or you get so angry you start smashing plates. When the appropriate thing would be to stay in the social nervous system: okay, there's a bit of stress, a bit of threat, but it's not such a big deal.

Healing: responding appropriately

Mindfulness and therapy can really help heal the nervous system. We see tons of research showing that when we practice mindfulness, the structures of the nervous system, and how they network together, begin to adapt. We move back into more appropriate responses.

There's a Zen koan I always like. The student asks the teacher, "What is the outcome of a lifetime of practice?" And the teacher says, "To respond appropriately."

That's what we're trying to do: attune the nervous system. When everything is good, you feel good, you feel safe. When there's danger, you go into fight and flight. And when the danger is inescapable, you go into freeze or shutdown.

Questions for reflection

1.  Think of a recent moment when you felt really safe and connected. What did you notice in your body: your breathing, your face, your voice?
2.  When you're in a conflict that isn't such a big deal, what does your nervous system tend to do? Do you stay connected, get angry, or shut down?
3.  When you feel anxious or threatened, how does your thinking change? Do you notice yourself becoming more judgmental, of yourself or of others?
4.  Have you ever frozen or shut down and then judged yourself for it? How does it feel to see that response as your nervous system trying to keep you safe?