Language, Origin of

What is Language?

Communication, which all forms of life engage in at some level, can be thought of as a process in which information is exchanged between individuals through a system of symbols, signs, and/or behaviors. This could include the use of odors that can determine rank, sexual status, location, and a host of other information forms of which humans have little understanding. Nonhuman primates make use of odors to express and convey some information, and humans do this as well to a certain degree. Where primates differ dramatically from other animal groups is in the use of gestures for communication. Gestural communication includes everything from the obvious, such as a sweeping hand or body motion, to the subtle, such as a slightly raised eyebrow.

Excellent examples of communication abound in nonhuman primates. For example, gelada baboons (Theropithecus gelada) live in the mountainous region of Ethiopia. The uneven terrain of their habitat makes it impossible for individuals in separate groups to communicate with each other using the vocal calls familiar to other primates and especially birds. Geladas use primarily gestures to communicate to distant groups often positioned at varying elevations. When the male of a group wants to send a warning to a male in an adjacent group, the first signal that he may give is a wide yawn that exposes his large canines. This somewhat benign gesture indicates to the other male that he is a little too close for comfort. If the adversary does not respond appropriately, he may receive a brief look from the male in which the eyebrows are briefly raised to reveal a patch of white skin around the otherwise dark skin eyelids. This gesture makes the eyes appear larger than normal and makes the other male understand that he is being watched closely. The gelada may engage in a variety of long-distance gestures that culminate in an eyebrow raise with a lip-flip accompanied by a sharp thrust of the body and face in the direction of the antagonist. This lets his adversary know that the next gesture may be actual physical contact, the ultimate gesture that most organisms avoid if possible.

Geladas, however, do not focus all of their gestures on aggression. They also use them to communicate sexual status. Geladas spend more time sitting than do other baboons and, as such, do not communicate sexual status to each other in the same way as is seen in other nonhuman primates. In most species of primates, females develop obvious swellings of the external genitalia around the time of ovulation. These swellings are an indicator or form of communication to males that a mating at the time of maximal swelling has a better chance of being successful. Geladas, however, do not produce swellings that are as obvious as those of other baboons. Instead, geladas possess a hairless patch of skin on the chest that changes color and develops nodules as the female enters into estrous. Moreover, like other primates, the female will solicit the male around the time of estrous to indicate that she is willing to mate with him.

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