mom'sfolly :
Again, my kid did this stuff to concentrate. It is considered "overflow" movement by his occupational therapist. We needed the OT for fine motor skills. The chewing helped him manage the other fine motor skills, for writing and piano. He is now thirteen, and his fine motor skills are better, but not the best. The kid is all about gross motor, has abs of steel, huge thighs and shoulders from the sports he does.
It doesn't have to be stress, especially if he does it mostly when he is concentrating. It is a method to help him concentrate. Some of these things are actually more common in children that are ahead of schedule. They sort of "skip" things developmentally that help integrate movement, and spacial sense. The kid might have lousy eye/hand coordination, but can ride a bike before any of his peers. Sometimes this early development manifests itself is strange ways. It doesn't mean there is a problem with the kid, only that the kid is developing differently.
I play with paper at the movies. I fold and refold my ticket into all sorts of shapes. This keeps me from biting my nails. This is NOT stress, it is merely business of my hands. I do this, because as an adult I realized the only time I bit my fingernails was in the dark, at the movies. I suppose the same could be accomplished with a crochet hook.
http://www.causeof.org/neuro.htm
AH HA! I can not have a paper napkin without it being folded a million times and then useless when I go to use it. I am all about fine motor skills and I always thought it was just my hands needing to 'do' something.
Yea, my movie tickets are dust by the time the movie is over. How interesting. I am not alone.
Oh. And about it being stress or anxiety, It does not have to be anything that anyone is
doing to him, or saying mean things. If he is a
thinker, then he will 'think' things to death. That will be the same as chewing your nails when surfing the net. it is mindless to him while his brain is occupied doing something else.
My son started after the 9/11 event. It got worse after the space shuttle blew up on re-entry. He was really young when he figured out that things were out of his parents control. It became a comfort, even though it had to be physically uncomfortable. I roll my index finger around my thumb in a circle when I am waiting for the dentist. My thumb is tender by the time it's over. But it helps relive the stress somehow, and I do not even realize that I am doing it.