Assist me in speculating

Tomorrow will be the last day of another training stint for work. Devices are upgrading and changing, so we gotta learn the new ones they're bringing in. Always boring but better than actually working.

And there's this guy in the class...

Good guy, nice guy, normal guy, smart guy, whatever people say when they don't lean one way or the other. But I did notice today, that when he's looking at the screen on his laptop he begins rocking, back and forth, like he's suddenly caught in the grip of a strange autistic impulse.

Seriously, it's the damnedest thing I've ever seen.

If someone talks to him and he looks one way or the other, the rocking stops immediately. As soon as his head swivels "eyes front" the rocking begins again, immediately. It is fascinating to watch, like a human metronome.

I'm rocking back and forth just thinking about it.

Has anyone else in the IT environment ever seen anything like this? If so, what is it? If not, whaddya think this is?

I'm completely distracted by it, mostly just because I can't ask him why the hell a laptop screen makes him rock. (I don't really know him other than his name is familiar within the context of my massive email load, which is 150 or so/day on weekdays--rigoddamndiculous.)

What if he's some kind retarded disabled handi-capable savant? What the hell would I say then? Do I fire off a range of quickly mumbled condolences in an effort to cover the spectrum of apology with the floundering hope of hitting on the correct apologetic sentiment, averting disaster and hopefully managing not to get sued and/or fired? Or, are congratulations the proper reaction these days? Congratulations! You'll never be fired (like I'm sure to be now) for implying that someone might be a retard, no matter what you say!

What if he has no idea he does it? That will only a) make him feel bad, b) piss him off (perhaps getting me punched), c) make him worried that he might be retarded, or d) all of the above. Somehow I don't think he'd be receptive to any proffered explanation that I'm only genuinely curious.

All I'm sayin' is that rocking compulsively back and forth in front of a glowing screen is fucking weird. Is this compulsion pre-existing or is it developing? So many questions...and yes, I'm aware that it's really not my business. I don't care, I still want to know.

Since I likely can't know, I am stuck with speculation. Help me out.

(perhaps I should consult The Bracelet, as he is a veteran retardation assessor)