Where did nodding, shaking head and shoulder shrugging come from?
Both the nod and the head shake seem to have recorded root in The Expression of the Emotions in Man and Animals, written by Charles Darwin in 1872. There are numbers of theories as to why nodding is so frequently used to mean “yes” – (note that in such places as Sri Lanka and Bulgaria, it is a sign of rejection.) A simple theory is that it is a form of bowing, indicating that one is prepared to accept what another person is saying or requesting. Darwin wrote to missionaries in many parts of the world asking for information on local gestures, and concluded that nodding for “yes” was common to many different groups. He also wrote that the head-shake is a universal sign of disapproval, disbelief, and negation. I couldn’t find the origin of the shrug. Sorry.
