I am sure this has already been asked somewhere, though unfortunately I have been unable to find it.

I recall thinking where our affirmative nod comes from and reading that it is supposed it came from bowing.

I am most interested in the nonverbal practices of the Late Roman Empire (or early 1st millennium W. Europe in general).

Did they have a "thumbs up"? To express uncertainty, did they have something akin to a shrug? In my mind some of these things seem so ubiquitous as to be universal but to know whether the people of the Roman Empire did the same would be so interesting!

Thanks.