New York Times article details the origins and importance of Italian Gestures.

Far more than quaint folklore, gestures have a rich history. One theory holds that Italians developed them as an alternative form of communication during the centuries when they lived under foreign occupation — by Austria, France and Spain in the 14th through 19th centuries — as a way of communicating without their overlords understanding.

Another theory, advanced by Adam Kendon, the editor in chief of the journal Gesture, is that in overpopulated cities like Naples, gesturing became a way of competing, of marking one’s territory in a crowded arena. “To get attention, people gestured and used their whole bodies,” Ms. Poggi said, explaining the theory.

Andrea De Jorio, a 19th-century priest and archaeologist, discovered comparisons between the gestures used by the figures painted on ancient Greek vases found in the Naples area and the gestures used by his Neapolitan contemporaries.

Over the centuries, languages have evolved, but gestures remain. “Gestures change less than words,” Ms. Poggi said.