All languages of the world involve accompanying gesticulations by speakers, but not all such actions are meaningful (convey meaning). When a speaker or hearer raises his/her eyebrows to signify incredulity or lack of comprehension, this is widely understood as a paralinguistic sign that may substitute for a speech act such as an expression of doubt in words. But such meaningful gestures are very much in the minority.
Contemporary American English is widely utilized by its native speakers with a mesmerizing assortment of gestures––mostly hand gestures–– that are not meant to convey any meaning at all and must be deemed silently senseless to their producers as well as to their interpreters/interlocutors. Whereas women are traditionally viewed as being more “expressive” or “emotional” than men during acts of speech, in twenty-first-century America both sexes produce these meaningless paralinguistic signs in great profusion. Why they do so is anybody’s guess. Perhaps senselessness is just a sign of our times.