Within the set of gestures that accompany speech, we can distinguish between those that echo, in some way, the content of the spoken message and those that indicate something being referred to. Iconics are gestures that seem to be a reflection of the meaning of what is said, as when we trace a square in the air with a finger while saying I’m looking for a small box. By itself, an iconic gesture doesn’t “mean” the same as what is said, but it may add “meaning.” In one particularly clear example (from McNeill, 1992), a woman was moving her forearm up and down, with a closed hand, as if holding a weapon, while she was saying and she chased him out again. The communicated message, including the weapon (actually an umbrella), was accomplished through speech and gesture combined.

Another common group of gestures can be described as deictics. the term “deictic” means “pointing” and we often use gestures to point to things or people while talking. We can use deictics in the current context, as when we use a hand to indicate a table (with a cake on it) and ask someone Would you like some cake?. We can also use the same gesture and the same table (with cake no longer on it) when we later say That cake was delicious. In this case, the gesture and the Gestures and sign languages 199 speech combine to accomplish successful reference to something that only exists in shared memory rather than in the current physical space.

There are other gestures, such as those described as beats, which are short quick movements of the hand or fingers. These gestures accompany the rhythm of talk and are often used to emphasize parts of what is being said or to mark a change from describing events in a story to commenting on those events. As with other gestures, these hand movements accompany speech, but are not typically used as a way of speaking. When hand movements are used in order to “speak,” we can describe them as part of a sign language.