5. The Social Engagement System

As humans we balance the need for social interactions with the need for safety. The need for safety is paramount. Immobilization is an adaptive function.

Dr Stephen Porges

There are two parts to the vagus nerve: the old and the new. The old vagus regulates the organs in the body below the diaphragm, especially the gut, and it connects to the heart. When things are running smoothly the old vagus conducts the overall flow of the digestive system and organs of the body. It is also involved in the release of hormones to help you with your day: dopamine (calm), serotonin (happy) and cortisol (stress).

When things are not going well and the system is under duress, the smooth flow of the old vagus is suppressed. The digestive system is shut down or slowed, there is a disconnection from the heart – from feeling – and there can be reflexive defecation. This physiological response is shared with other animals in response to threat: they, we, freeze. It is a safety mechanism. The old vagus enables this defensive response.

The new vagus is regulated by the parasympathetic nervous system which operates when we are calm and safe. In this state we are open and engaged with our world, and we spend our time growing, healing and restoring the body. The vagus nerve, when we are in this calm state, works closely with the social engagement system. The vagus nerve gets its information about what to do next through the social engagement system.

The social engagement system involves neural pathways embedded in several cranial nerves that develop in utero. It essentially controls the muscles we need to engage with our world. It controls the eye muscles – seeing, looking, engaging; the facial muscles – facial affect; the middle ear muscles – smiling, laughing, chewing, ingesting; the laryngeal and pharyngeal muscles – voice prosody; and the head-turning muscles – social gesture and orientation.

The vagus nerve chats to the social engagement system – it relays information to and from it. Information comes in via the eyes, ears and mouth and travels through to the body via the vagus nerve. Depending on whether the information coming in is ‘safe’, the vagus nerve will instruct the body to parasympathetic behaviour (calm, engaged, smiling, open) or sympathetic (argue, move away, shut down).

These two systems are in direct communication; they support each other. They work to allow the person to make sense of the world, to interact, to be safe. When we are safe, we use the social engagement system to communicate verbally and non-verbally. We smile, we observe faces, we listen, we talk, we incline our heads and we raise our eyebrows. We do these things because we want to, we do them because our bodies can do them, and we do them when our bodies are set to the parasympathetic.

These ‘social’ muscles function as filters that limit and allow social stimuli. Hence they determine the individual’s engagement with the social environment.

Dr Stephen Porges

Our social engagement system allows us to use our eyes and ears and face to connect with the world, to communicate. It is unique to mammals. Iguanas, lizards and snakes do not have the necessary system to make eye contact, to smile and communicate with their friends. Mammals do. Lions hang out together. Monkeys chat and share food. Cats, horses, giraffes and rabbits all groom one another and spend time together. We are like them, yet we have an even more complex brain and an even more complex social network.

The social engagement system is how we engage with the world. We smile, we speak, we look, we listen, we laugh, we turn our heads; we breathe easily and let the world in. The world comes in and we come out, through the social engagement system.

The social engagement system operates when we feel safe. It enables friendly, social interaction and this helps us to be in a calm state for good health and restoration of cells. However, the social engagement system does not work so well when we are in Fight, Flight or Immobilization. It more or less goes offline as we are engaged in looking after our safety.

You don’t need social niceties when you are running or fighting for your life, and you don’t need them when you are frozen to the ground in fright. The brain diverts attention to where it is needed, and social engagement has less priority when your brain perceives you are in danger. As with your digestive system, in times of danger the social engagement system is automatically turned down or off.

Like lions and monkeys, we save our grooming and hanging out with friends for when we are in a parasympathetic (calm) state. When lions are angry or scared, they are less likely to be open to making friends and having fun as they need to be focused on staying alive. When their sympathetic system is activated, there is not much need for the social system to be operating either. Their energy is needed for safety.

Generally our old system and our new system are in perfect harmony. We are calm, we interact, our heart rate is normal, we can digest food easily, and we breathe calmly. As well, we can speak easily, make good eye contact, smile, turn our heads gently, and listen to the nuances in a conversation. We can move and interact with grace as well as digest food and repair our cells. When we are calm there is enough energy to go around.

As we grow we learn to use our body to modulate our environment. As well as learning to interact when things are good, we can also learn to do other things when things aren’t as harmonious. We can learn to use our ears to block out noise that is too loud, we can learn to make good eye contact and smile at new people to make them feel safe, and we can learn to breathe slowly to calm ourselves down. We learn to do these things with our body. We learn to use our eyes, our ears, our mouths and voices to modulate our environment. It gives us a good level of control over what’s going on around us.

If we somehow don’t have a level of control over what is going on around us we can get a bit stressed. Our cortisol will go up. Depending on the level of adversity, we might go into Fight or Flight. We might go into anger or aggression, or we may withdraw and move away until we feel better. When we get back to being calm we can get back to interacting nicely with people again. If we are Immobilized we might faint, or disassociate, and then it can take quite a bit longer to get back to feeling like ourselves, back to a calm operating system.

The social engagement system is our new evolutionary software. When you are small you learn to operate it. You learn how to smile appropriately, you learn what noises to listen for, you learn to look for comfort and you can learn to use it to calm down. You learn to ‘read’ what is going on in your external world and how to respond to it. You learn to integrate your brain and your body to best respond to your external world.

But what if this does not happen so well? What if when you were young you didn’t learn to use this social software? What if when you were very small, your system had been distressed for some reason and all your energy had been diverted to your safety? What if you had gone into the Fight, Flight or Immobilization response and, being so young, you had not known how to get yourself back out? What if your FFI had just been left on too long?

This is the Polyvagal Theory. Dr Porges thinks that many autists are people for whom, as infants, the vagal system was diverted to the body’s safety and this then became the focus for the growing child. The body system, Immobilized, becomes painful or agitated, digestion is difficult and the child’s focus turns inward. Interaction with the outside world is compromised.

As the child’s focus turns inward and less focused on the outside world, the natural integration of the social engagement system does not take place with as much ease. As the sympathetic system does not allow easy access to the social engagement system, the child does not learn how to use their system well. They do not learn to control their social software, to drive it, and so it ends up working more on autopilot and their FFI is like a runaway train.

Social situations, because they are highly complex, require a well-functioning social engagement system; otherwise they become a minefield of sensations. Autists, because they have not set up the software needed to process the information properly, can read threat in the environment and go quite quickly through FFI, to shut down.

Autism is like being given an itchy jumper to wear by your Granny. While all the other kids in the playground are off running and jumping in the playground, the autist is stuck dealing with Granny’s itchy jumper

All sorts of noises, smells and sights come in and the autist has not learnt how to regulate the information, nor how to regulate the body’s response. Their system overloads, it triggers the FFI and they Immobilize.

The theory is that autists have a reduced capacity to engage with the world because they have not learnt to process complex social data; this triggers the FFI and it goes off willy-nilly.

This can be slight or profound. Some autists can learn some social skills but not be able to access them all the time; while for some, they virtually stay Immobilized.

Dr Porges thinks that autism is perhaps not a genetically determined neurological deficit, but a response to stress or trauma that happens quite early on for the child. He thinks that, for whatever reason, the vagus is disposed towards Immobilization, and because of this the child’s nervous system does not get fully developed. It can be slight. It can be strong emotional trauma, a fear that presents in utero or at birth, a physical disruption of the vagal nerve, fever, antibiotics, vaccines, or a response to x, y, z.

The point is not what it is a result of, but that it is a fact that the child’s system has been in a state of distress. Instead of the old and the new getting wired up together as they should, they end up sitting separately from each other. Instead of knitting together nicely from birth, the new system is there and the old system is there, but they haven’t got to talking too well. So the baby misses out on the full integration of all that the social engagement system has to offer and the eyes, ears, face are all more, or less, offline.

This is where the ‘autism spectrum’, the ‘continuum’, comes in. The connection between the social engagement system and the vagus nerve is just that, a connection. It can be strong, it can be faulty, and it can be switched off under duress. It can be a bit strong, weak sometimes, high-functioning at other times.

We can all be a bit autistic, because it is a part of normal human function. We can all shut down in certain circumstances. Autists just do it frequently. Autism is a physical reality and it is part of our natural human experience.

It can make a huge difference to the autist to understand that what is happening is a physiological response, that it is not ‘them’… Informing the autist that this is just ‘triggered circuitry’ can be profoundly liberating for an autist.

Dr Stephen Porges

The social engagement system literally links the face to the heart. Reptiles do not have this physical link. Not only do they not smile, but they cannot pay attention to their feelings. They are shut off from the heart – physically.

We, like other mammals, are not shut off from our heart. We have anatomy that allows us to feel, and to express what we feel. When the body is registering extreme stress, or fear, this mechanism switches off. When we are really angry or scared, it is much harder to feel the softness of the heart, we close off to it. We literally close our bodies off. Autists, more or less, have less ability to access their heart, and they can switch off from it faster than we can. They physically have a weaker link to their feelings, and being able to express their feelings.

The neural control of the heart is neuroanatomically linked to the neural control of the muscles of the face and head.

Dr Stephen Porges

The social engagement system links the face to the heart.

It is how we show the world who we are.

If it has turned itself off, for whatever reason,

people cannot see what we are feeling.

We just look blank.

If we are constantly Immobilized,

we might even feel blank.