A new study (http://rsbl.royalsocietypublishing.org/content/early/2010/08/05/rsbl.201...), published in the latest issue of Royal Society of Biology Letters, indicates that forest-living orangutans spontaneously pantomime, acting out incredibly detailed scenarios with their bodies, to communicate with humans and other apes. In addition to being used to request or to deceive - both believed to be typical of great ape communication; this study suggests that pantomimes may also be used for complex roles like elaborating on a failed request, telling a story, reminiscing, or making a statement.
PANTOMIME
The word 'pantomime', derived from two Greek words 'pantos' meaning 'every, all'and 'mimos' meaning 'imitator/actor', is defined as the telling of a story without words, by means of bodily movements, gestures, and facial expressions. This popular form of entertainment is believed to have originated in Ancient Greece, where one or more actors would enact several different parts in a theatrical performance, accompanied by a narrative chorus.
PANTOMIMES IN THE EVOLUTION OF HUMAN LANGUAGE
Most studies on the origins and evolution of language have typically compared human speech with animal vocalizations. A growing body of literature over recent years has, however, indicated that language might have originated from gestures rather than vocalizations.
A gesture, in this context, is usually defined as a nonlocomotory movement using hands, feet or limbs in a way that has communicative value and is directed at another but does not necessarily involve touching another person or substrate. A tactile action is considered as a gesture only if it lasts for two seconds and visibly lacks the mechanical force to bring about the reaction shown by the recipient.
While all primates regularly communicate with each other through vocalisations, orofacial movements, body postures and locomotion patterns, free brachiomanual gestures have been seen limited to only humans and apes. Studies have indicated that gestures are also neurologically distinct from other forms of bodily communication in both production and perception by others. First described in chimpanzees, most other anthropoid apes, like bonobos, gorillas and orangutans, have by now been observed to use gestures to convey information.
PANTOMIMES AND MIMICRY
The evolutionary significance of pantomimes in the development of human languages is controversial. Some studies treat pantomimes as a method of communication that relies on simple mimicry rather than on conveying meaning. Others suggest that not only does a pantomime convey meaning, it is different from mimicry in being a symbolic activity. Thus a mimer must possess the ability to grasp that one object or action can stand for or signify another object or action. This is complicated by the fact that not all gestures are symbolic. For example, while declarative pointing requires symbolization, imperative pointing is instrumental. Also, gestures can either be triadic or dyadic - triadic gestures draw the attention of others to something in the environment; dyadic gestures constitute a way of requesting behaviour of others towards oneself. Not being reciprocal, the ability to produce these gestures does not imply the capacity to understand their use by others and vice versa. Complex imitation may account for how dyadic gestures that are part of ritualized behavior can initiate interactive sequences; but such gestures are not the same as pantomimes. Pantomimes can be unconventional and spontaneous; they also are almost always interactive. Grasping the function that a non-ritualized pantomime is supposed to perform demands perceiving or ‘reading’ the intention behind the gesture, and perhaps even understanding how the intentions of the mimer is related to one’s own states and actions.
THE CURRENT STUDY IN BRIEF
Studies have shown that captive great apes may elaborate on messages if communication fails. Isolated reports have suggested that they also occasionally pantomime. However, the current study is the first to investigate the ability to pantomime and its use in free-ranging apes. It is also the first to suggest that, unlike what is conventionally believed, these pantomimes are used by orangutans to spontaneously convey meaning with multiple functions, and often with propositionally structured content.
Russon and Andrews, the authors of the current study, started with the hypothesis that forest-living orangutans would pantomime spontaneously to communicate, and especially to elaborate, after communication failures. To prove this, they mined about 20 years of text and video data from observational studies on orangutans in Indonesia. Most of the orangutans studied were those that had been rescued from illegal pet-trade and sent to programs that attempted to rehabilitate them in the Bornean rainforests.
From these records, the authors have highlighted 18 occasions of what they interpret as orangutans acting out a request or using the elaborate gestures of a pantomime. On 4 of these occassions, one orangutan mimed for another; and on 14, an orangutan mimed to a human. According to the authors, this might reflect the fact that messages might fail more often when an orangutan addresses them to a human in comparison to those addressed to other orangutans; humans being less adept at correctly understanding their messages.
In one instance, an older female orangutan named Kikan used a pantomime directed to a human helper to re-enact how this helper had healed the ornagutan's foot by removing a stone that had pierced it with a pencil and applying latex from the stem of a fig leaf to dry the wound. In another instance, Siti, a young female orangutan, made a hole in a coconut by punching through one of its three eye-like depressions and broke off a leaf stem to suck out its juice. When she had exhausted what she could reach through this opening, she took the coconut to a man in the camp who would occasionally slice open coconuts with a machete. Since the man was supposed to encourage the forest residents to do such chores by themselves, he handed the nut back to Siti. Siti then adopted an exaggerated air of exhaustion poking at the inside of the coconut with her leaf straw. Not getting any response from the man, she used her leaf stem to make chopping-style slashes against the the coconut, in what looked to Russon as the mimicry of a man using a machete.
When they pantomimed amongst themselves, the orangutans communicated instructions, like "scratch me with this stick," "eat this fruit," and "wipe your dirty face off with this leaf" etc.
Interestingly, one of the themes in 13 of these examples is the miming orangutan's elaboration of a breakdown in communications, which according to the authors, suggests at their ability to understand something of what their partner, human or ape, didn't understand.
EVOLUTIONARY SIGNIFICANCE
That gestures and pantomimes are limited to great apes and humans is believed to add credence to the theory that languages might have evolved from manual gestures, and over time shifted from a manual to a vocal mode. They are believed to be indicative of a recent evolutionary shift towards a more flexible and intentional communicative strategy in our pre-hominid ancestors. One sign of this shift comes from contextually defined usage of gestures - a single gesture may communicate entirely different needs or intentions depending on the social context in which it is used. Especially since gestures seem less closely tied to specific emotions and may permit greater cortical control than other forms of communication, which can also derive extra meaning from the context in which they occur. Thus, while vocalizations are better adapted to signaling emotional states, such as fear, territorial claims or aggression; primate hands and arms are more readily adapted to conveying information about events that are structured in space and time. This is also supported by studies which claim that our shared ancestry with primates have endowed us with hands that provide a more natural signaling system than that provided by the voice. Non-human primates have relatively poor voluntary control over vocalization, but being arboreal, they have evolved excellent and flexible control over their forelimbs.
Many reasons have been proposed for the shift to a form of communication that relies more on sound than on sight. One set of theories suggest that this move might have stemmed from the fact that although sign language has all the expressive potential of speech, it suffers from certain physical restrictions. Not only do acoustic signals command attention more readily than visual signals, speech allows communication in the absence of light or where visual access to the speaker is blocked. Speech also frees forelimbs for manufacture, tool use or other purposes; has lower energy requirements; and aids development of pedagogy. Another set of theories suggest that speech gave us the ability to overcome the heavily iconic nature of manual communication - many a gesture or a sign bear a visual relation to what they represent in contrast to the arbitrary nature of speech.
What is still hotly debated and poorly understood is the nature of the switch that would have been needed to move from a visual language to an audible one. Armstrong and Wilcox, in their book titled "The gestural origins of language", in a hypothesis consistent with the motor-theory of perception, suggest that speech by itself is gestural in nature and composed of movements of the lips, velum and larynx; and the blade, body and root of the tongue. Its arbitrary nature is therefore not a fundamental property of human languages but rather the consequence of the medium through which these gestures are expressed. Thus, language may have always involved vocalizations and movements of the face as well as of the hands, and signed languages are as much facial as manual. Conversely, spoken language is characteristically accompanied by manual gestures. Evidence from primate vocalizations and hominin fossils indicate that the anatomical and neural changes necessary for the intentional production of articulate sounds, however, might have occurred late in hominin evolution, with the ability to sustain autonomous speech developing only after Homo sapiens emerged, about 200,000 years ago. Armstrong and Wilcox support this claim by referring to evidence that the FOXP2 gene, involved in vocal articulation, is known to have undergone a mutation within the past 100,000 to 200,000 years, which according to the authors may have been a final, crucial step in the evolution of human languages. They also indicate that this evolution might have been aided by the large increase in brain size that coincided with the emergence of the genus Homo, and might have been a response to the enhanced dependence on cooperation and social communication driven by dramatic ecological changes in the Pleistocene era.
CONCLUSION
In addition to corroborating other observations of pantomimic gestures in great apes, some of which have been doubted to be instances of anthropomorphizing; this study, among others, presents a way to look at the deep evolutionary origins of human language.
Though gestures remain very much alive in human communication, producing them has become so automatic that it is relatively immune to the effect it has on the audience. Thus, for example, blind subjects are known to gesture at equal rates as that of sighted subjects to a known blind audience. Also, gestures are no longer produced in the absence of other communicative signals, such as facial expressions and vocalizations; possibly because when speech is used together with gesture and vision, it may result in more robust, natural and efficient communication.
This indicates that in humans and other animals, a multi-modal form of communication - which allows both verbal and gestural cues, can have a variety of functions, including the amplification and modulation of signal meaning. Combined with the graded facial/vocal signals typical of the apes, gestural flexibility might allow greater communicative complexity than the more stereo-typed signaling strategies used by monkeys.
REFERENCES
1. Orangutan pantomime: elaborating the message. Anne Russon and Kristin Andrews. Biol. Lett. published online before print August 11, 2010, doi:10.1098/rsbl.2010.0564.
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3.The Mirror System Hypothesis. Linking Language to Theory of Mind. Michael Arbib. Coevolution of Language and Theory of Mind. (http://www.interdisciplines.org/coevolution/papers/11)
4. From parity and complex imitation to pantomime. Ingar Brinck. Coevolution of Language and Theory of Mind, Sep 22, 2004. (http://www.interdisciplines.org/coevolution/papers/11)
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9. The Free Dictionary (http://www.thefreedictionary.com/pantomime).
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