Reviving this for another "how do you tell the difference?" question (like current one on echolalia) on how one knows one is in "stim" territory. Ds does have quite a few behaviours like those described below (especially pacing while talking, singing through people talking to him, letting out shrieky noises for no apparent reason - things which if dd did them would stop me in my tracks) so I'm trying to find some kind of line to draw. Anyone know of any technical descriptions?
I'm working along the lines below (this isn't just ASD thoughts, it's more general). Thoughts welcome:
(1) tic: involuntary - you don't know you've done it till afterwards; doesn't seem to have a significant sensory element; fairly persistent trait of behaviour (lasts for months). Examples: blinking, arm twitching.
(2) comfort habit not within autistic (or other unusual) spectrum: voluntary but in certain kinds of mood/context (eg boredom, worry) difficult to suppress; indicates a normal set of sensory responses; very persistent (lasts lifelong). Examples: pen-twiddling in boring meeting, leg-jiggling on Tube, hair-twiddling when watching TV ... nose-picking ...
(3) ASD stim: semi-voluntary, very related to mood/context (eg (especially) overload feelings), redirection very difficult; form taken indicates something unusual going on in sensory terms; persistent? - don't know. Examples: rocking; finger-flicking; noises that probably sound interestingly odd in one's head.
(4) annoying slightly weird but ultimately NT habit not to stress about: voluntary, if a little difficult to suppress (but does respond to redirection); connected to an obvious (possibly novel) sensory source; more or less transient. Examples: irritating fake "Mutley" sounding laugh probably copied off schoolmate; having lost lower front two teeth, shooting one's tongue through the gap like a gormless snake.
I'm trying to fit the singing and shrieking into category (4), but I'm not quite confident I can.