Talking with our hands is one of the most human things we do. While commonly used to add emotional emphasis to spoken language, hands have the unique ability to convey complex information silently, secretly, and over relatively long distances. Hand signs are essential to the daily practices of individuals as diverse as the deaf, Buddhist monks, gang members, and baseball players.

Primate hands have evolved over tens of millions of years for moving efficiently, usually through trees. When our ancestors began to walk upright, their hands were freed to become increasingly specialized as sensitive and precise instruments for manipulating tools and carrying objects, serving as a powerful interface between the expanding human brain and the environment. All non-human great apes use hand gestures in the wild and are capable of being taught hundreds of human signs. Monkeys also use their hands to communicate—as can be seen in a recent TED Talk, when a capuchin uses its hands to convey outrage over unequal treatment. However, as with spoken language, humans have a uniquely prodigious aptitude for complex and abstract expression with our hands.

This video excerpt from Aboriginal Australia highlights a region where hand communication is especially prominent and central to daily life (for the full eight-minute video click here). Over two shoots, just outside the remote community of Balgo in the Great Sandy Desert of Western Australia, women elders from the Kapululangu Women’s Law and Culture Centre demonstrate marumpu wangka, “hand signs,” and translate them into both English and their native Kukatja. Framed by corrugated dirt roads and a panoramic cliff face cutting dramatically along its edge, Balgo is home to around 500 people living in three camps surrounding a dusty red sports field.

Hand signs serve a variety of roles in Balgo. Hundreds of signs are regularly exchanged between community members regardless of hearing ability. A silent commotion often buzzes around the most common sign. Translated as “what?,” this sign is remarkable in its nearly limitless potential for meaning depending on social context. (Linguistic anthropologists call this kind of flexible symbol or concept that can mean many things to many people a floating signifier.) The usual response to the “what?” sign is the sign for “nothing,” indicating that there is no need to take action.

As people who often possess superior eyesight, many Aboriginal people can see signs over especially long distances. Signs are also essential for silent communication while hunting. They are often used to trade in secrets—especially in the presence of cultural outsiders, where the contrast between the signed and spoken is a source of comedy. Signs serve important cultural purposes as well, relating to speech taboos around stepmothers and widows, and they match local values of dignified efficiency in communication. As seen in the video, hand signs are not only a way of communicating information, but also serve as full-bodied ways of expressing nuance, humor, and personality.