One of the three characteristics of Autism Spectrum Disorder is the presence of the movement disorder called repetitive behavior. Repetitive behaviors are defined by their repeated occurrence, inappropriateness, and behavioral rigidity1. Repetitive movements can range from simple stereotypic movements, such as rocking, swaying, and finger tapping to self-injurious actions such as head banging to more complex routines or rituals, such as repeated counting of objects or preferred household/bedtime routines.

Repetitive behavior occurs in all children, including neurotypical young children, from 18 months up to the age of six2. You’ve probably also engaged in a limited form of such behavior if you ever sat at your desk, repeatedly tapping your pencil or foot! When limited, repetitive behaviors are thought to be adaptive, helping to reduce anxiety and providing a way to organize and adjust to our environment3.

It is the increased frequency and extended duration of such behavior in children with ASD and other neurodevelopmental disorders to the point of impairing daily life, however, that makes it maladaptive and a movement disorder4. The stereotypical movements can also stigmatize the person, impairing their socialization.

Repetitive behavior is not unique to autism. It occurs in other neurodevelopmental disorders such as, but not limited to, Tourette’s syndrome and obsessive-compulsive disorder. Repetitive behaviors can increase in frequency due to internal behavioral states such as anxiety, stress, boredom, or excitement5.

In this section, a scientific expert reviews the motor pathway in the brain, repetitive behaviors in neurotypical children and those with ASD, and what is known about repetitive behaviors and brain differences. The neuroscientist also outlines the considerable research challenges in addressing this trait of ASD. The ubiquitous nature of repetitive behaviors occurring in a variety of neurodevelopmental disorders makes an understanding of its underlying causes, and corresponding treatment more difficult. We also do not understand the brain differences associated with the normal repetitive behavior seen in development and the abnormal repetitive behavior seen in individuals with neurodevelopmental disorders. The fact that the differences must be quantitative, not qualitative, make it harder to find a definitive cause.

Key Points

• Repetitive behavior is one of the three diagnostic traits for ASD.
• All children engage in repetitive behavior as infants and preschoolers.
• Repetitive behavior helps young children improve motor skills and may reduce anxiety.
• For patients with ASD, repetitive behavior becomes maladaptive because it increases in frequency and duration to the point that it impairs daily life.
• Repetitive behavior is not unique to ASD. It occurs in other neurodevelopment disorders as well.

Misconception

Repetitive, stereotyped behaviors are abnormal.

Fact

Repetitive behaviors are a normal part of child development. It is the frequency and duration of repetitive behavior in patients with ASD that can impair daily functioning.