I’d like to look at an important distinction about thumb-sucking. This comes from my experience as both an Infant Developmental Movement Educator and Aware Parenting Instructor.

I see two different situations, both of which tend to be called “thumb-sucking,” but they’re very different! One offers benefits to physical health and the other offers challenges to emotional health.

Sucking for movement integration

This type of thumb (or finger) sucking is called “mouthing.” For typically-progressing children, this doesn’t extend beyond babyhood. It’s a reflexive mouthing of the hands for young babies and mouthing of toys/objects for middle/older babies.

There’s a high number of nerve endings in the mouth, so it’s like another sensory limb for babies, a way they sense and learn about their world. It often involves all the fingers or fist–which means it can involve the thumb alone–and here is where it can cross over into the sucking described below.

But first, back to mouthing. Think of a young baby ‘mouthing’ her fist while snuggled in your arms or on her tummy. As she aims her hand to her mouth, she is also measuring–getting an internal sense of her own body in relation to itself.

Sometimes she will wriggle from her head all the way down to her ‘tail’: mouthing can get the entire digestive system revved up!

This kind of mouthing is calming and grounding because it tones the organs. It stimulates the inward, organ-monitoring Parasympathetic Nervous System rather than the outward sensing/motoring Sympathetic Nervous System.

Mouthing, along with having baby’s head, neck, and body in aligment while nursing or bottle feeding, helps to organize the movement of the head, neck, and jaw. It also supports self-feeding later by building hand-to-mouth coordination. And a fun fact: mouthing can help stimulate the thumb’s journey out of the little tiny baby fist!

Sucking that holds back feelings

Now let’s look at something very different. This is the more classic image of thumb sucking and can have an autopilot quality to it.

This type of sucking does not tend to engage the whole body in a wriggling dance like mouthing. It’s more passive and can be used to fall asleep, when upset, or otherwise seems habitual.

This type of thumb sucking is more widely know as ‘self soothing.’ The reality is that it tends to stop feelings from flowing. Let me explain… 

A baby sucking his thumb for this reason may appear calm or independent, but is most likely feeling some pent-up emotion, whether recent or old. The thumb in the mouth holds the feelings in, rather than letting them be expressed. Aware Parenting calls this a ‘control pattern.’

Here’s the detective question: what would baby do if he weren’t sucking his thumb?

Many parents answer that baby would cry, or else aren’t sure. This is the clue that will unlock a whole new world of understanding for you and your child!

Babies need a “pressure release valve” by crying in arms, with your loving, listening attention. Crying (in arms) releases the pent-up feelings behind that thumb. It’s physically and emotionally healing.

This is new information for most parents, so this is not a guilt trip! It’s a learning opportunity 🙂 In this scenario, thumb-in-mouth is a way for baby to stop himself from crying–he may not feel safe to cry, or it’s very common that parents may not have been aware of this need to cry.  But please don’t pull his thumb out of his mouth! For much more in-depth information about supporting this, please reach out to me or see Aletha Solter’s books, including “The Aware Baby.”

How to tell the difference

Here’s the tricky part: mouthing can also turn into pent-up-feelings sucking! Here are some clues to begin deciphering them:

  • Does Baby’s sucking engage her whole wriggling body or seem autopilot?
  • When something stressful happens, does Baby let out his feelings or suck his thumb?
  • Does Baby seem engaged in sucking as an activity, particularly during tummy time; or does he have a blank or concerned look in his eyes?
  • Does the sucking involve only the thumb as a habit, or at times the other fingers, fist, toys, or clothing in exploration?

One more important scenario

Babies sometimes suck in an attempt to self adjust cranial bones. Traversing through the birth canal is a big squish! On the other hand, coming out the top (C-section) is void of that big squish!

In either case, or for other reasons, the many tiny and bigger bones of the face and skull can get a little bit stuck. Craniosacral Therapy can help greatly in this scenario–alongside an understanding of emotional release!

For babies with additional medical needs, please consult with professionals.

Also, I do not see this as always black and white. It can be; and the part about babies needing an outlet for their feelings and someone to listen is clear, and this is a legit need for all babies. But for some families, there are more layers, like birth stress/trauma or tongue tie, that we need to add into the picture in conjunction with an understanding of emotional support.

© Elizabeth Parker 2012 and 2022, All Rights Reserved, links welcome