Two traits of autism that are in the popular vernacular: 1) autism presents across a spectrum and 2) autistic people will not look you in the eye.
As for Number One, it is the norm for all kinds of human traits. Stating it reminds us that a label like autism is not a UPC (uniform personal code?) that guarantees the contents of the human inside. It is Number Two that is the foundation for this post, and also the foundation for the continuing research into the neurological basis for autism.
V.S. Ramachandran is a highly-regarded researcher into the mysteries of the brain and the nervous system. He writes for those of us who are fascinated on a practical level, and he has a wonderful sense of humor. His latest book is "The Tell-Tale Brain", published by W.W.Norton and Company. I recommend it highly to teachers, especially the chapters on mirror neurons and autism.
V.S., as those of us who would like to be his friend call him, has been involved in significant research that proves the link between non-functioning mirror neurons and autism. Mirror neurons are the elements of the brain that allow us to imitate what we see, sometimes called the "monkey see, monkey do" neurons. Autistic people do not have the same mirror neuron response to human actions as non-autistic people, making it difficult for them to adapt a standard of social interaction that we classify as normal.
However, what is even more fascinating - or frustrating, if you are a parent of an autistic child - is that mirror neurons function ideally in connection to an understanding of the concept of self. Without a concept of self, the ability to imitate appropriate behaviors is limited.
The word "autism" suggests a quality of self-absorption, exhibited through a failure to display interactions with others that fall somewhere in the spectrum of normal. I have thought for a long time that this meant an autistic person was overly interested in the self. This is true, but the framework for that interest comes from the inability to feel secure as a separate self. This explains why some autistic people subject themselves to head banging or other extreme sensory self-stimulation. They want to know that they are there, somewhere in there, functioning on at least a sensory level that gives some feedback for their separateness.
It is this link between sense of self and sense of others, according to current theories by V.S. and others in the field, that is missing for people with autism. Without a secure sense of self, a person can not allow that self to imitate other people.
It may be that forthcoming research will demonstrate that high-functioning autistic people, such as those classified with Asberger's syndrome, actually have a more functional mirror neuron network than those who are low-functioning. It still may be more limited than "normal", but it may prove to be the source of the different levels of functioning.
For those of us who depend so heavily on the principles of imitation in our profession, learning more about mirror neurons and the sense of self can be extremely helpful. If you are currently working with students with autistic traits, it is necessary.
April is Autism Awareness Month, the ideal time to explore and learn more about autism.