It may not be a tic as such, but still a way of coping. It's perhaps worth mentioning to the doctor, but also - why don't you just ask him why he does this? he probably has a perfectly logical (to him) reason for doing this.
I've mentioned before - unless a tic or stimulant is socially unacceptable or causes problems (such as tooth grinding which can lead to teeth wearing down and jaw muscle spasms) we don't interfere. We've found our kids do better and are less stressed if we leave them alone. They ARE often aware of social problems resulting form some tics and stims and were they are aware of it, they do try to move towards tics & stims (especially stims) which are less obtrusive.
Have you read "The Curious Incident of the Dog in the Night-Time" by Mark Haddon? It explains stims from the point of view of the person on the spectrum. The character in that book (it is fiction, a novel, but brilliantly written) does not make eye contact for reasons which are well explained - he says he can pay better attention to what people are saying, if he avoids eye contact. The book explains a great deal about exactly what it can be like, living in an autistic brain.
What your son may be doing, could be the best way HE has found, to get as much information as possible from what the person is saying. WE consider that the best way to listen to a person is to also watch their face - we observe the movement of their mouth (which also helps our brain 'double-check' the words spoken) and we also scan their face for hints in facial expression that can indicate subtle nuances of mood in the speaker, so we can then 'colour' the words we hear with the overtones of relevant emotion. But for someone on the spectrum - such messages are often misread and can lead to misunderstandings. That is often a reason for them failing to make eye contact - so they won't be DISTRACTED by the speaker's body language and facial expressions, which to someone with autism can seem to be out of context.
They find all sorts of interesting ways to both gather the information they need, and do it in as socially acceptable way as possible - for them.
From what you've said before, I gather that you are raising your son to feel good about himself and his diagnosis. If so, he should be approachable on the subject, you should be able to discuss this with him, find out how aware he is of what he is doing and if he has a reason. Or maybe he was just a bit bored and was trying to maintain his interest?
One thing I've found - there's never a dull moment with these kids. If he can help you see through his eyes, it can help you (with your wisdom of years and life experience) to ease him along the path to a productive independent life.
Marg
