In a breathless episode of The Language Files (previously), host Tom Scott explains why humans gesture with their hands while speaking. Linguists who study these paralinguistic movements have categorized them into five different categories.
1. Iconic. These gestures represent a literal object, such as a flat surface, or a car weaving through traffic.
2. Metaphoric. Gestures that symbolize an abstract concept, like “before” and “after”, or “working together”.
3. Deictic. That’s pointing to things, positioning yourself to people, or places or things.
4. Pragmatic. Like offering the floor to someone, or “don’t bother me right now”.
5. Beat. The rhythm of gestures alongside the natural stress patterns of speech.