If you or your family are neurodivergent in some way, you may have come across the following terms: hyperfocus or hyperfixation, special interest, and stimming.

These are three types of behaviour that are very common in people with ADHD, autism, or both. They can often be assumed to be the same thing but are actually three distinct behaviours that can nevertheless occur in the same person and at the same time.

We're going to do a series on all three.

We have already shared information about hyperfocus and hyperfixation. And we have posted about special interests. This post will be about stimming.

‘Stimming’ as a word comes from the descriptor ‘self-stimulatory behaviour’ and is often seen in people with autism. It is repetitive actions that assist the person in self-regulating their behaviour, feelings, or mood.

Stimming is usually a repetitive motion, the most familiar to non-autistic people being hand-flapping and rocking, but the definition can and has expanded to include other repeated actions. It can also include flicking or tapping fingers, pulling or twirling hair, flexing feet, or fidgeting with jewellery or clothes.

Stimming does not have to be a movement; it can also include repeatedly singing or saying a phrase, listening to something over and over again, or watching something happening repeatedly. Someone may start doing a stim without noticing, but once identified, it can be done purposefully as a coping mechanism.

Stimming provides consistent sensory input in an environment where the person is receiving inconsistent or overwhelming sensory input. The input could be external stimulation, such as loud noise in a supermarket or other public place, or internal stimulation, such as ‘noisy thoughts’ or a strong emotion.

The strong emotion doesn’t have to be negative – autistic people frequently stim in response to strong feelings of happiness or excitement. It has been reported that stimming when happy can actually accentuate the positive emotions, making the autistic person even happier.

Research suggests that stimming is by and large a positive activity, and that the biggest negative that results from stimming is the external reaction to it.

At various times, ‘treatments’ to control or reduce someone’s stimming have been popular but that is, thankfully, changing as autistic people have defended and explained the need for stimming.

Parents may have tried to reduce stimming in their child, for fear of stigma, but this can result in the child feeling stifled or even more overwhelmed, and occasionally results in the autistic child finding stims that may be less obvious but perhaps more harmful.

Harmful stims do exist, and can include excessive hair-pulling, skin picking, and banging or hitting limbs or the head. Providing different and less damaging sensory input at times of distress may be a useful way to redirect the child away from harming themselves. Examples include strong hugs that provide full body pressure, or a hand firmly pounding their back to provide a rhythm. Rocking chairs and sensory swings can also assist in providing rhythmic input.

It is possible that someone with ADHD and autism might exhibit all three of the behaviours in this series, by hyperfocusing on a special interest while stimming. For example, if someone loves stimming by chewing on silicone jewellery, they might get curious as to how it’s made and start looking online, triggering the creation of a special interest. There are a lot of videos on YouTube of how silicone is coloured, or how different silicone products are made in factories, and so this person might watch them obsessively, enjoying the repetitive nature of the video (a visual stim), while learning about the process and then telling all their friends and family members about it (also known as ‘info dumping’). They may do this research for hours at a time and be difficult to distract from the topic or unable to notice what’s happening around them while engrossed in that activity (hyperfocus).

Stimming is a normal activity for a neurodivergent person and is not usually a cause for concern. If you are worried about a particular behaviour, talk to your child or observe them quietly when they are doing it, and see if you can figure out why this particular behaviour is useful or rewarding for them.

That ought to give you some guidance on what other less-worrisome activities may be attractive to your child so you can start slowly introducing new stimuli and redirecting their behaviour.