Stimming is the abbreviated term used to describe self-stimulatory behaviors, which are clinically known as stereotypies. Both children and adults can exhibit stereotypies from time-to-time for a variety of reasons. While stereotypies are most often associated with autism and/or other developmental disorders, normally developing children and adults may engage in self-stimulating behaviors, though the cause for the behavior is often unclear.
What Is Stimming?
Self-stimulatory behaviors are described by professionals in a number of ways, but they are primarily characterized by making repetitive movements, echoing sounds or phrases (echolalia), staring fixedly at rotating/spinning objects, arranging objects in a stylized manner, and/or other seemingly purposeless acts. Stereotypies are generally classified into two types: primary (or common) and secondary (or complex). Common stereotypical behaviors can include, but are not limited to:
- Thumb sucking
- Head banging
- Nail biting
Complex or secondary stereotypies include:
- Hand flapping
- Arm waving
- Wrist flexion and/or extension
- Atypical gazing at objects
- Abnormal pacing, running, and skipping
Normally Developing Children
All people may evidence stereotypical behavior at times, and children are no exception. About 65 percent of neurotypical infants, and about 50 percent of children under 15 years of age, may show primary motor stereotypies like rocking, thumb sucking, or nail biting. Complex motor stereotypies like arm waving or hand flapping may occur in up to three or four percent of normally developing preschool children.
When stereotypies are seen in neurotypical children, they are sometimes associated with sleep behavior. They may be part of a self-soothing, before-bed ritual that helps them prepare for sleep. They can also be associated with other transitory times, like meals or bath time. Most of these types of self-stimulating behaviors will fade as the child ages. Repetitive behaviors like foot tapping, crossing and uncrossing legs, and tapping fingers on the arm of a chair are considered normal adult stereotypical behaviors.
Children With Medical or Developmental Disorders
While the underlying cause for stereotypies is not clear, repetitive movements are associated with a number of medical and/or psychiatric conditions:
- Sensory deprivation (blindness or deafness)
- Seisures or brain infection
- Intellectual disability
- Drug use
- Psychiatric disorders like autism, obsessive-compulsive disorder, and anxiety
- Undiagnosed pain
- Pervasive developmental disorders (PDD)
It is important to rule out any underlying medical condition that may be causing pain or discomfort before making a diagnosis of a developmental disorder or other psychiatric condition. Children who are non-verbal may not be able to articulate their symptoms of pain and thus may smack their head or face if they have a headache or sinus infection. Stereotypies that are indicative of pain would be likely to have a sudden onset with few, if any, other co-morbid developmental symptoms.
Unfortunately, it can be very challenging to determine whether stereotypies are primarily associated with pain, a developmental disorder, or other mental health condition. This can be frustrating for parents and medical practitioners alike. While many stereotypical behaviors are recognizable as such, they can also present as uniquely as the children who express them. However, there are some indicators that are more likely to point to a diagnosis of autism or other developmental condition.
In a study evaluating 277 children conducted as a collaborative effort among several New York universities, researchers found that children with autism and a non-verbal IQ of less than 80 were more likely to exhibit stereotypies than children with non-autistic developmental disorders. Additionally, they discovered that the stereotypical behavior of atypical gazing at fingers or objects was almost always associated with a diagnosis of autism. Abnormal pacing and skipping are highly correlated with a diagnosis of autism as well.
Resources for Parents and Caregivers
While a diagnosis of autism or any other developmental disorder can be very frightening for parents, there is a wealth of information available to help parents learn how best to support their children. Keep in mind that children with disabilities are generally quite happy and fulfilled, just as a neurotypical child would be with the same loving and supportive environment. Early identification and finding a specialist to work closely with will help ensure that all your child's needs are being met and that you have access to all the available resources to help support your child.