Willard wrote:
A Stim (sterotypy) is a repetitive movement done to offset autistic anxiety (you may not be consciously aware of it, if you've lived with it all your life, but autistic people are in a near constant state of anxiety). Rocking, Swaying, Leg bouncing, hand flapping - all stims. Done because they are soothing.
Hair twirling, nail biting, etc - fidgits, not stims. They may also occur due to anxiety, but are not particularly soothing to the nervous system.
Just because something can be said to be technically "self stimulating" does not necessarily qualify it as a 'stim' in clinical terms.
http://autism.about.com/od/autismterms/f/stimming.htm
Quoted:
The term "stimming" is short for self-stimulatory behavior, sometimes also called "stereotypic" behavior. In a person with autism, stimming usually refers to specific behaviors such as
flapping, rocking, spinning, or repetition of words and phrases.
Stimming is almost always a symptom of autism, but it's important to note that stimming is also a part of most people's behavior patterns. If you've
ever tapped your pencil, bitten your nails, twirled your hair, or paced, you've engaged in stimming.
It says "reviewed by the medical review board". I am only showing what some doctors think.