Most children on the spectrum engage in repetitive movements like rocking, bouncing or hand flapping. Stimming, as these movements are commonly known, is a key feature of autism spectrum disorders (ASD).

As an autistic adult, I’ve noticed that parents are often curious and sometimes concerned about their child’s stimming. Why does it happen? What does it mean? Why does it get worse at times?

Why Do We Stim?

Stimming happens for many reasons. I stim when I’m anxious. I stim when I’m thinking. I stim when my senses are overloaded. I stim when I’m happy. Stimming is a way of regulating my body and mind. It calms me when I’m over-stimulated and reconnect me with myself when I’m under-stimulated. Often I don’t even notice that I’m doing it.

Stimming can take many forms. In addition to repetitive movements, some people stim by repeatedly touching, smelling or tasting things. Others stim by chewing on objects.It’s impossible to say how we pick up our favorite stims. I think most people with ASD would say that they choose us rather than the other way around.

As a child, I was constantly in motion. I liked to rock and bounce and jump and swing. I twirled my curly hair around my fingers from the minute I got on the school bus in the morning until the last bell rang. Now that I’m an adult, many of my stims are discreet. If we were sitting across from each other at lunch, I doubt you would know I was stimming unless I told you. I might be fiddling with a pen, rubbing a bottle cap between my fingers, folding my straw wrapper or jiggling my foot under the table.

Our stims change over time, but I don’t think I’ve met an autistic adult who doesn’t stim in some way. We stim at our desks. We stim in meetings. We stim on the subway or as we drive. I’m even stimming while I write this. Every time I stop to think, my fingers are dancing lightly on the keys, helping me gather my thoughts.

What Does a Change in Stimming Mean?

Parents are often concerned or alarmed when their child’s stimming increases in intensity or frequency. It’s important to remember that stimming is not only a way of self-regulating, it’s a form of communication. Learning to “read” your child’s stimming can be a valuable tool in identifying what type of coping tools or accommodations they might need.

For example, recently I was out to dinner with my family at the start of a serious illness. By the end of dinner, I was in quite a lot of pain and had started bouncing my fists on my thighs and rocking a bit in my chair. Both my husband and my adult daughter noticed that my stimming was unusually strong and asked, “Do you need to leave?” The sudden change in intensity told them that something was very wrong, even if I wasn’t verbally expressing it.

Often, a change in frequency or intensity in stimming has environmental antecedents. A busy, noisy, crowded, sensory-overloading environment can temporarily increase the need to stim. The same is true of intense social interaction, a major change in routine or living environment, an unexpected event, an emotionally upsetting circumstance, a challenging cognitive task, physical pain or a demand (social, physical or emotional) that exceeds a person’s ability to cope with it.

This is where the detective work begins. Look at what’s happening around the child or what’s changed recently. Don’t assume that only negative changes cause an increase in repetitive behaviors. Sometimes stimming increases during transition times, like the first week of summer vacation, as the child adjusts to new routines. Summer vacation is fun, but the shift from school mode to vacation mode can be hard. During this time, a child might need a little extra time alone, less sensory input, or fewer demands on their resources. Once they’ve adjusted, stimming generally goes back to its usual level.

Not all stimming is stress or anxiety related. Stimming is a natural part of being on the spectrum and often not a cause for concern. However, a sudden increase in stimming may be a sign that additional support or accommodations are needed until the child is able to develop new coping strategies.


Cynthia Kim is the author of “I Think I Might Be Autistic: A Guide to Autism Spectrum Disorder Diagnosis and Self-Discovery for Adults”. She blogs about her experiences as an adult with late-diagnosed ASD at