“An elaborate and secret code”
[W]e respond to gestures with an extreme alertness and, one might almost say, in accordance with an elaborate and secret code that is written nowhere, known by none, and understood by all (Sapir, 1927, p. 556).
This apt quote by Sapir (1927) points at two important characteristic features of gestures (1) our acute ability to detect them and (2) to interpret (decode) them although we do not necessarily have any special education in nonverbal communication. It is worth noting that gestures differ in different cultures as well as in different contexts (e.g. in construction, builders have their own gestures which may mean something different to people who do not belong to this profession). Remarkably, we tend to react to gestures and to trust them sometimes more than we trust words since it is easier to mislead with words than with nonverbal behaviour and also because gestures communicate through the visual channel rather than the aural and the visual channel is often a more powerful source of information that the aural channel. For example, if a tour guide who speaks English as a foreign language says “We must go back” and at the same time points forward with his hand, we are more likely to move forward than to go back trusting his nonverbal behaviour more than what he is saying verbally.
Sapir, E. (1927). The unconscious patterning of behavior in society. In D. G. Mandelbaum (Ed.), Selected writings of Edward Sapir (pp. 544–559). Berkley: University of California Press.