Updated: Feb 10, 2019
Frequently in a online support group for parents of autistic children, someone will describe an unusual, repetitive behavior their ASD child is displaying, and will ask if it's stimming. This may be an action such as waving or flapping an arm or hand, spinning, touching an object or some part of their body. It may also be a sound, such as tuneless humming or singing, or repeating a word or phrase over and over again. Usually the answer is yes, this is stimming. If it's a repeated action that the child does over and over again, that doesn't seem to accomplish anything, it is most likely stimming. Stimming is short for self-stimulating, and is a coping mechanism and in my experience is usually done for one of two reasons (or both).
First, it may be a forming of venting. In autism, we tend to have a lot of pent-up energy, coming from anxiety caused by an overactive fight-or-flight response. This overactive fight-or-flight leaves us constantly ready to respond to things, even when there's nothing to respond to. So we have constant pent-up energy that we had to do something with, so we stim, to give that energy some place to go. Along these lines, stimming can also be a happy stimming, where a child is using the stimming as an outlet for happy-excited energy.
Second, it may be what is known as gate control. Gate control is using one sensation to cover up another sensation that is unpleasant, so named because it acts like a gate, blocking the unpleasant sensation from registering in the brain. Everyone does gate control from time to time in response to pain, autistic or not. If you've ever banged your head on something and covered your head with your hand, or burned or cut yourself and put your lips on it, you were engaged in gate control. You were using the sensation of your hand or lips to help bock the pain signal from getting to your brain. In autism, the unpleasant sensation we're trying to cover up comes from sensory overload. So much information (including sensory information) is being passed to the decision-making part of the brain that we don't know what to do with it. So we stim. The stimming behavior helps block out the other sensations and information because our brains focus on that instead. In that way, it can be soothing and calming for us.
For those curious, I do stim myself from time to time, even as an adult. My most common stimming is usually something I do in private or in the company of only my wife, and is usually verbal, taking the form of a wordless growl. My wife says that I also stroke my goatee when I'm nervous.
A frequently asked question on the subject of stimming is whether or not the stimming should be allowed or if it should be discouraged. This will greatly depend on the circumstances and the specific stimming behavior, but here's my two cents on it. Keep in mind that when I say all of this, I am not a counselor, therapist, doctor, teacher, or even a parent. If your child is physically harming themselves, others or is breaking things, yes I would say something needs to be done about it. If it is something rude or crude and will get them in legal trouble, yes I would do something about it. If it is completely disrupting the space they're in, like a classroom, then maybe. But otherwise, if it's just an unusual behavior that isn't socially appropriate but is otherwise harmless, I would advise caution on stopping them from doing it. Remember that stimming is a coping mechanism to deal with forms of stress that they're experiencing, and if you take a coping mechanism away, it may make things worse. Since I'm not a therapist, I will be candid and say that ABA therapists may disagree with me on this advice. ABA therapists will discourage stimming at home, as permitting it at home may encourage it in public as well - this would be especially true if a child has trouble distinguishing when a behavior is appropriate or not.
As I described in my inaugural blog post, I created Decoding My Autism to help share what I know and answer the questions that parents have about their autistic children. What would be helpful to you? What questions can I address? Please let me know in the comments!