If you have ever seen a child rapidly flapping their hands or rocking back and forth, you may have wondered what it means.

One readily noticeable pathognomonic trait of autism is hand-flapping—a stereotyped motor movement that can look a bit like an attempt to accelerating the drying of nail polish. Not all with autism do ...

Repetitive motor behaviors (RMBs) such as hand flapping and rocking occur in more than one third of toddlers who do not meet diagnostic criteria for autism spectrum disorder (ASD), with higher rates ...