The Moro reflex is a neonatal reflex, or otherwise known as a primitive reflex. It is present at birth and is usually integrated by the age of 12 weeks. You might know it as the Startle reflex in your baby.

Sometimes, primitive reflexes can be retained beyond the natural developmental age, and this can cause some “startle” behaviours long after 12 weeks of age (or 3 months of age).

In my practice, I see a strong connection between retained Moro and lowered vagal tone, often leading to nervous system dysregulation in kids.

Testing for a retained Moro

Think back to when you had a baby (if you have had one). The startle response generally occurs when you place your baby down backwards, and you may have even seen your primary heatlhcare provider testing it by ‘dropping’ your baby backwards a little (and catching them of course). It can also be elicited with a loud noise, causing the person to jump.

The Moro is in two phases -

The arms come out wide
The arms tuck in close, and the baby/child/adult might actually start crying

It is normal for a baby to cry within those first 12 weeks when the reflex is strong. If you are an adult, and you feel really jolted by a ‘startle’ afterwards, like you want to cry or feeling really agitated, this is a sign your Moro is still retained and strong! This might also be the case for your child, when they get shocked or overloaded.

You can test the Moro by either coming up behind someone and clapping loud, or you can pretend to drop their head backwards while they lay down on a table. Either can elicit the Moro, and it might just be a little jump or it could be as extreme as a huge jump with arms out followed by cowering forward.

What are retained reflexes?

Retained reflexes are the ‘baby’ reflexes that should be integrated well before 12 months of age. Integration of primitive reflexes is actually via inhibition of them. So the more the brain develops optimally, the more the reflexes will be inhibited.

When reflexes are retained, what it indicates at the very baseline is that the nervous system has adapted in a way that it needs to keep these responses active. This is also a neurodevelopmental ‘imbalance’ (so to speak), because a nervous system that is developing as expected will inhibit / integrate these reflexes at the appropriate time. It is my personal experience that the biggest cause of primitive reflex retention is STRESS - preconception / womb-life / early childhood stress. And that stressor may look very different for everyone, but at the root of it, it is a stressor to the nervous system that seems to dampen optimal neurodevelopment.

Signs of Retained Moro Reflex

The startle, when you think about it for a moment, is the way you respond when your nervous system detects a threat in your environment. If you hear a loud noise, or see something moving towards you quickly, you might startle (or gasp and jump a little).

There are varying degrees of behaviour with a retained Moro but the ultimate manifestation from a nervous system point of view is that something is threatening enough to trigger you immediately into fight or flight.

Now imagine if your Moro is very strong.. well you’re probably going to have a stronger tendency to spend more time in fight/flight (because everything feels threatening!). This sounds a lot like lowered vagal tone, does it not?!

Some of the general signs of a retained Moro include:

Hypersensitivity
Hyper-reactivity
Poor impulse control
Sensory overload
Social and emotional immaturity
Motion sickness
Poor balance and coordination
Easily distracted
Don’t cope with change
Mood swings

There are so many overlaps between ADHD and retained startle. And let’s not forget the “jumpy” adults, who seem worried and anxious over everything!

What I consistently see in practice is those children and adults who have retained reflexes just do not get the full resolution of their symptoms by stimulating their vagus nerve alone. Perhaps they’ve even tried all the things. I mean ALL THE THINGS. And are still not getting anywhere with their nervous system regulation capacity.

Because these reflexes sit so closely in the brain to the vagus nerve, it is possible that the reflexes dampen the vagus nerve’s ability to do it’s job optimally. Neurons (nerve cells) can communicate not only between synapses but between different neurons too, meaning anything in the same vicinity has the ability to affect literally anything else in the same vicinity. My mind was blown the first time I learnt about this - it really opens up so many more possibilities as to what is going on in someone’s vagal tone.

Do you have a retained Moro? Try it and see!

Want to learn more about Primitive Reflexes?

Not sure where to start with your child’s dysregulation?

The Primitive Reflexes Course is for Mums looking to learn all about primitive reflexes and how they affect their child’s development - you’ll probably learn a thing or two about yourself too!

Learn how to support your child’s development, their ability to handle stress, and optimise their brain development.

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