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What Causes Stimming in Autism

Written on . Posted in Autism, Stimming

Stimming is a behavior typically displayed by people with autism and sensory processing difficulties. It can present in a number of ways, including verbal and auditory stimming – discover the different types of stimming in our previous blog post. So what causes stimming?

Although there is not one specific cause of stimming, there are a few theories which suggest potential causes. These possible stimming causes are best unpacked in further detail to fully grasp the complexities of the likely reasons for stimming. The causes vary between individuals and depending on the severity of their autism.

What Causes Stimming?


One possible cause of stimming is linked back to understimulation. When it comes to autism, some may be under-sensitive to a particular sense. For example, if someone is under-sensitive to a sense, they may present the following signs or symptoms:

Sight – finding objects dark, sharp peripheral vision but blurred central vision, magnified primary object, poor depth perception demonstrated by problems throwing or catching

Sound – only hearing through one ear, not able to hear certain sounds, unfazed by crowded or noisy environments

Smell – no sense of smell or inability to smell potent odors, licking things to get a better idea of the flavor as they can’t rely on scent

Touch – displays a high pain threshold which can lead to self-harm, squeezes people or animals tightly, chews on objects or prefers heavy objects such as weighted blankets

Vestibular – seeks sensory input through rocking, swinging or moving

Proprioception – unaware of personal space, struggles to avoid obstructions

Taste – enjoys very hot or intense flavors and practises pica which is when someone eats non-edible items

The way stimming helps understimulation has been referenced by an article in Parents which shared an example of a woman who said stimming enabled her to feel parts of her body which had previously felt dulled.


An alternative cause of autism is often connected to overstimulation. In contrast to understimulation, some people stim because they feel overstimulated, which can lead to difficulties regulating emotions. In these cases, stimming can help focus and calm individuals. However, stimming can also become counterproductive and even harmful if taken to extremes. Those oversensitive may have the following experiences:

Sight – vision distortion, more comfortable to find a focal point than focus on a larger object, sensitive to light

Sound – magnified sounds, unable to filter out background noise from conversations

Taste – extra sensitive taste buds which are overwhelmed by strong flavors or unusual textures

Touch – pain when touched or sensitivity to certain clothing textures

Vestibular – struggle with sports activities, car sickness and stopping quickly

Proprioception – difficulties with fine motor skills so uses the whole body to make slight movements

Smell – overpoweringly intense smells such as perfumes and air fresheners

Some studies suggest that stimming helps release endorphins, helping individuals feel comforted. This might explain why individuals often stim when feeling when distress or anxiety.

We hope this article gives you a better understanding of the reasons behind stimming. For details examples of stimming, please see our previous post.

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