Stimming is a repetitive body movement that self-stimulates one or more senses in a regulated manner. Stimming is known in psychiatry as a "stereotypy", a continuous, seemingly purposeless movement.
Stimming is one of the symptoms listed by the DSM IV for autism, although it is observed in about 10 percent of young children without autism. Many autistic children have no stims. Common forms of stimming among autistic people include hand flapping, body spinning or rocking, lining up or spinning toys or other objects, echolalia, perseveration, and repeating rote phrases. 
There are many theories about the function of stimming, and the reasons for its increased incidence in autistic people. For hyposensitive people, it may provide needed nervous system arousal, releasing beta-endorphins. For hypersensitive people, it may provide a "norming" effect, allowing the person to control a specific sense, and is thus a soothing behavior.  Stimming is a natural behavior that can improve emotional regulation and prevent meltdowns in stressful situations.
Some common examples indulged by an autistic person is presented below :
|Visual||Flapping hands, blinking and / or moving fingers in front of eyes; staring repetitively at a light|
|Auditory||Making vocal sounds; snapping fingers|
|Tactile||Scratching; rubbing the skin with one's hands or with an external object|
|Vestibular||Moving body in rhythmic motion; rocking front and back or side-to-side|
|Taste||Licking body parts; licking an object|
|Smell||Smelling objects or hands; other people|
The above is only an illustrative list, and there may be several other stimming actions displayed by an autistic person.
Quiet Hands and Abuse Edit
Some therapists believe that stimming should be suppressed, so that autistic children will appear more "normal." They use the words quiet hands to train autistic children not to stim. Frequently this involves physically restraining the child until the child complies automatically.
Many individuals in the autistic community believe that this training is abusive. Julia Bascom's famous personal essay describes the trauma, shame, and fear that Quiet Hands instilled in her. Quiet Hands has been called "the equivalent to duct taping [a non-autistic] person’s mouth shut or preventing a nonspeaking D/deaf person from signing." Suppressing of stimming is believed to impair executive function, making it more difficult for autistic people to pay attention, collect their thoughts, and focus on tasks. Many autistic adults protest the suppression of stims in children.
- ↑ "Prevalence of stereotypy among children diagnosed with autism at a tertiary referral clinic", K.A. Crosland, presented at the Association for Behavioral Analysis annual conference, May 25, 2001.
- ↑ "Stereotypic (Self-Stimulatory) Behavior (Stimming)", Stephen M. Edelson, 1995.