Well now I'm just intrigued. I'd like to study this, but watching groups of women seems like a really good way to get a restraining order and a court summons.
I do the nod, myself, if within close enough range to perceive head movements. If the distance is too far for said movements to be seen, I just wave like a loony.
I do the nod, myself, if within close enough range to perceive head movements. If the distance is too far for said movements to be seen, I just wave like a loony.