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Baby Stimming At Nine Months (Explained)

Have you ever heard the term stimming before?

Does your baby flap their hands a lot? Or maybe rock back and forth all the time? These are examples of stimming.

Many people associate stimming with Autism or the traits related to Autism Spectrum Disorder. It certainly can be the case that children with Autism do have a greater tendency to stim, but did you know that we all use stimming to some extent?

Stimming behavior doesn’t necessarily mean that a person has Autism and for babies stimming is a completely natural part of their development.

I’ve worked in early education for the last twenty years, and in that time I’ve come to understand that the majority of babies who demonstrate stimming behavior later develop completely normally with no signs of autism.

In this post, I’ll take a good a good look at what stimming is, why babies do it, and any signs you should look out for.

nine-month old stimming by sucking hand

So What Is Stimming?

Put simply, stimming means moving your body in a way that calms or regulates your mind.

Have you ever tapped your toe when you are bored or fed up?

Scratched your head when you are confused? 

Waved your hands around when you’ve been excited?

These, often unconscious behaviors, are all types of stimming behavior. 

We all do a bit of stimming to some extent and for the vast majority of babies, toddlers, children, and adults, it’s completely normal and nothing to worry about.

So why do babies use stimming behaviours?

Most people start stimming when something happens to trigger stress, anxiety or we feel overwhelmed about something.

They may even be happy or over-excited. It could be triggered by an unexpected change or an event coming up that we feel a bit nervous about.

Using repetitive body movements can actually help to soothe those feelings. It can help us to feel calmer and it can reduce our levels of stress and anxiety. Imagine it as a sort of physical outlet for those uncomfortable feelings.

Now put yourself in the mind of a nine month old baby….

Practically everything in their world is brand new to them.

They are met daily with new experiences, new exciting tastes, mind-blowing sounds, amazing sights, new textures, and fascinating smells. Their little brains are developing rapidly and are making hundreds of new connections at a fast rate, every single day.

Their world is all totally new. It’s such an exciting place with lots of new faces, new language, new toys. Put yourself in their position for a moment! There is an awful lot for them to process.

It’s not surprising that all babies cry and all babies use stimming behaviors to some extent. We could think of it as their outlet for all those unsettling feelings that they can’t yet tell us about.

It’s no wonder then that all babies need to stim to calm themselves down and cope with all the new experiences that can sometimes feel distressing or can threaten to overwhelm them.

Common Stimming Behaviors


Most babies like to be rocked, and this is probably the earliest form of stimming behaviour that we experience. Rocking back and forth in a regular motion soothes babies.

Something about the regular motion, and repetitive rhythm accompanied by a soothing voice often helps to calm them if they are overwhelmed, feeling anxious or distressed.

We’ve all seen babies stop crying and calm down when they’re rocked, often to the rhythm of a song or rhyme.

Rocking can work to calm older children too, especially if a child has a developmental delay. Even some adults may benefit from rocking movements if they need to be soothed. You may have seen this at a funeral or in times of great distress when we revert back to patting and rocking a loved one.

Thumb Sucking

Thumb sucking is another form of stimming.

Regular sucking motion is, for some babies, a way of soothing themselves.

You may notice a child sucking their thumb when they are tired, worried, or feeling overwhelmed. Not all children suck their thumb, some prefer to suck a dummy or soother, a piece of blanket, or even their sleeve, but again, this is a repetitive soothing motion that helps to regulate our feelings.


Some babies like to soothe themselves by rubbing their hands or face repetitively on a particular blanket, a piece of silk, or a piece of smooth material, or they may just enjoy the feel of rubbing their parent’s face, neck, or chest. It’s comforting to them and there is nothing wrong or unusual about it.

Child sucking their hand while stimming
Sucking of a thumb, hand or material is one of the commonest types of stimming behaviors

Observing Your Nine-Month-Old

If you stand back and observe a nine-month-old baby, you will usually see a host of stimming behaviors and at this stage, it’s absolutely nothing to worry about. They are literally soothing their frazzled brains from the many new activities and experiences that they face every day.

You may see behaviors like:

  • Rocking back and forth
  • Repetitive behaviors like stroking of skin or textures
  • Loud squealing sounds
  • Hands clenching and unclenching
  • Thumb sucking
  • Finger flicking
  • Licking objects
  • Mouthing objects
  • Looking at new objects from strange angles
  • Arching their back
  • Spinning or twirling
  • Holding their fingers out at an angle
  • Flapping their arms (or legs)
  • Wide eyed staring or squinting
  • Posturing (holding their body in a rigid way)
  • Banging their fists or kicking their legs
  • Repetitive sucking
  • Twirling your hair (or their own)

These are just a few repetitive stimming behaviors, but there are many more. The important thing to remember is that these are all a normal part of development for babies. We will all have used a repetitive behavior or two ourselves when we were babies to cope with the new exciting world around us.

It’s thought by scientists, that physically moving in a repetitive way may produce endorphins or feel-good chemicals in the nervous system, so your baby is quite literally calming themselves down or learning to regulate themselves, a key skill we all need to learn in life.

Reasons For Stimming Behaviors

There are as many reasons for stimming as there are stimming behaviors.

  • A few typical reasons for a nine-month-old stimming could be:
  • They are feeling overwhelmed and need break.
  • They are over tired and need to sleep.
  • They are feeling overstimulated (too much going on) and need some calm time.
  • They are feeling bored and need more stimulation, thus showing self-stimulatory behavior.
  • They are feeling worried or anxious but can’t tell us why
  • They are trying to maintain their focus and the stimming helps them to do so.
  • They are really excited and happy about something.
  • They may be trying to communicate something to us (I’m hungry, thirsty or wet).
  • They may be trying to cope with changes in their routine (transitions).
  • They may be overwhelmed by too much attention or noise.

Stimming doesn’t generally cause anyone a problem

You might be worried that your child showing repetitive behaviors like stimming automatically means he or she has Autism stimming or Autism Spectrum Disorder. It’s not always the case.

If children still have a lot of frequent stimming behaviors, even if they are older, remember that they are only doing their best to regulate themselves. There is no need to stop them unless it is causing them bodily harm. (Source)

For example, if a child starts to develop repetitive head-banging behavior you should talk to your medical professional.

As most children grow older, stimming usually starts to fade, in the same way as they stop crying when they are hungry and start sleeping through the night. This is perhaps because as a new language develops, children become better able to explain or ask for what they need.

However, most of us still have some stimming behaviors without even realizing it.

I still know an adult that sucks their thumb (in secret) and another adult that twirls their hair around tightly when they feel anxious, (for example before an interview). I work with another adult that paces back and forth repetitively when they’re frustrated or angry.

See if you can think of stimming behaviors that you have seen recently in your family or work colleagues.

Remember, these behaviors are only a problem if they have the potential to cause physical harm. For most people, they are nothing more than a way of soothing an uncomfortable feeling. For some people, doing a repetitive behavior may even be pleasurable. For others, stimming may become more of a habit than a need.

Questions To Consider

For a nine-month-old baby, stimming is almost certainly a sign of typical development.

The key is to try and identify why they’re doing it and to think if there is anything we can do to help them. Consider:

  • Do they need a break?
  • Are they ready for a sleep?
  • Can they be taken somewhere quieter?
  • Do they need you to rock, soothe or cuddle them?
  • Do they need to be sung to, in a soothing way?
  • Are they in need of more stimulation, for example a different toy or a change of scenery?
  • Are they bored?
  • Do they need to see your face?
  • Is there too much going on?
  • Is there too little going on?

Remember! Young babies use repetitive movements and self-stimulating behaviors frequently. They need to do it to cope with the world around them. It is perfectly normal.

As The Child Grows

As children grow, these behaviors will usually slowly begin to be replaced by other activities.

You may notice that rather than flap their hands and squeal, they may go to play with a favorite toy instead to soothe or regulate themselves. Rocking back and forth on their tiptoes and other repetitive behaviors may disappear once they become more mobile and active.

Once their language and words start to develop, they will have less frustration because they can tell you what they want and so will have less need to regulate themselves by stimming.

Stimming is a self-soothing or self-stimulatory behavior. We are usually unaware that we are even doing it. Now you know about it, you might catch yourself or the people around you stimming in many different ways.

One of the best ways to help your child through this phase in their development is to concentrate on giving your nine-month-old lots of opportunities for physical development, for example:

  • Crawling
  • Tummy time
  • Baby gym
  • Reaching and stretching for toys
  • Space to roll and pull themselves up
  • Lots of fresh air and outdoor time
  • Climbing and playing on you (rough and tumble play)
  • Laughing with you (laughing uses lots of different muscles)

Physically active children tend to be more confident and independent too.

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