Self-stimulatory behavior, also known as stimming and self-stimulation, is the repetition of physical movements, sounds, or repetitive movement of objects common in individuals with developmental disabilities, but most prevalent in people with autism spectrum disorders. It is considered a way in which autistic people calm and stimulate themselves. Therapists view this behavior as a protective response to being overly sensitive to stimuli, with which the individual blocks less predictable environmental stimuli. Sensory processing disorder is also given as a reason by some therapists for the condition. Another theory is that stimming is a way to relieve anxiety, and other emotions.
Common stimming behaviors (sometimes called stims) include hand flapping, rocking, excessive or hard blinking, pacing, head banging, repeating noises or words, snapping fingers, and spinning objects. Stimming is almost always a symptom of autism, but it is also regarded as part of some non-autistic individuals' behavioral patterns. The biggest difference between autistic and non-autistic stimming is the type of stim and the quantity of stimming.
In the Diagnostic and Statistical Manual of Mental Disorders, published by the American Psychiatric Association, this type of behavior is listed as one of the symptoms of autism or "stereotyped and repetitive motor mannerisms". There are numerous ways to reduce or eliminate stereotypic behaviors. Some of them include providing an individual with alternative forms of stimulation; drugs have been used to reduce stimming (however, it is not clear whether the drugs are actually beneficial or restrict the individual from finding relief). The majority of the autistic community opposes attempts to reduce or eliminate stimming as stimming is an important tool for self-regulation. Many contend that attempts at cessation of stimming is abusive as it inflicts suffering upon the autistic individual. This is one of the major reasons that the autistic community tends to oppose ABA therapy (among a plethora of other reasons including the use of shock treatments and the very basis of ABA—compliance training). 
- Rosalind Bergemann (2013). An Asperger Leader's Guide to Living and Leading Change. Jessica Kingsley Publishers. ISBN 9780857008725.
- Valerie Foley (2011). The Autism Experience. ReadHowYouWant.com. ISBN 9781458797285.
- Stephen M. Edelson, Ph.D. "Self-Stimulatory Behavior". Autism Research Institute.
- Gretchen Mertz Cowell (2004). Help for the Child with Asperger's Syndrome: A Parent's Guide to Negotiating the Social Service Maze. Jessica Kingsley Publishers. ISBN 9781846420429.
- Eileen Bailey (15 July 2011). "Autism Spectrum Disorders and Anxiety". Health Central. Retrieved 25 March 2014.
- Temple Grandin, PhD (November–December 2011). "Why Do Kids with Autism Stim?". Autism Digest. Retrieved 25 March 2014.
- Eileen Bailey (27 August 2012). "Stimming". Health Central. Retrieved 25 March 2014.
- "Stimming: What autistic people do to feel calmer". BBC. 5 June 2013. Retrieved 25 March 2014.
- Lisa Jo Rudy (13 October 2009). "Stimming". About.com. Retrieved 24 March 2014.
- “Autism Spectrum Disorders”, 1994, Diagnostic and Statistical Manual, American Psychiatric Association
- "Autism and Stimming" (PDF). Autism West Midlands.
- "Meet the company that's making jewelry for adults with autism | The Daily Dot". The Daily Dot. 2016-07-20. Retrieved 2017-10-01.
- "On Stimming and why “quiet hands”ing an Autistic person is wrong". The Caffeinated Autistic. 2013-02-10. Retrieved 2017-10-01.
- DeVita-Raeburn, Elizabeth. "Is the Most Common Therapy for Autism Cruel?". The Atlantic. Retrieved 2017-10-01.
- "My Thoughts on ABA - Autism Women's Network". Autism Women's Network. 2015-02-11. Retrieved 2017-10-01.
- "The controversy over autism’s most common therapy | Spectrum | Autism Research News". Spectrum | Autism Research News. 2016-08-10. Retrieved 2017-10-01.
- "I Abused Children And SO DO YOU: A Response To An ABA Apologist". Diary Of A Birdmad girl. 2017-04-25. Retrieved 2017-10-01.
- Stephen M. Edelson, Ph.D. "Self-Injurious Behavior". Autism Research Institute. Retrieved 29 March 2014.