Speaking of minimal unconscious hand movements when giving directions, it's obvious (to me) that this is related to what everybody (in my experience) does when spoon-feeding a baby.

WHAAA?????

That's right, you open your mouth, don't you?

Before someone says, "That's to get the baby to imitate you," I will say I believe we rationalize it that way, but it's more than that. I see adults (maybe newlyweds or sweethearts, but not necessarily) in a restaurant feeding each other say a sample of a particularly good dessert, and --guess what?-- there's almost always a little mouth motion --maybe only a parting of the lips, but sometimes an overt mouth-opening-- that goes with it. The "feeder" is WILLING that receiving mouth to open, and that thought, through the feeder's own internal hard-wiring, has its unknowing effect, and the feeder's mouth moves.

So, too, a direction-giver, visualizing say a right turn, then a left turn, tends to express the right-then-left thought through the body (maybe with minimal, unthought hand gestures, maybe with an tiny inclination of the head, maybe a slight lean right or left) which is obedient to thoughts at a more ready, basic level than speech.

Dave Oesterreich