Ape+gestures+and+language+Evolution

SUMMARY

Chimpanzees and Bonobos use gestures, vocalization and facial expressions to communicate with each other. Of the two, bonobos are more responsive to multimodal signals. Whereas Chimpanzees show no greater responsiveness toward multimodal communication. Gestures seem to be less attached to emotions than vocal and facial forms of communication. Thus gestures are considered to be a sign of cognitive control rather than an automatic reaction to some particular stimuli. Some gestures have been found to have different meaning in different contexts which shows that the gesture is flexible and not static to just one particular context.

Here is a link to an article that basically summarizes the main points from the //Ape Gestures and Evolution// article we read: http://www.newscientist.com/article/dn11756-bonobos-and-chimps-speak-with-gestures.html

GLOSSARY

=A= b: any of two families (Pongidae and Hylobatidae) of large tailless semierect primates (as the chimpanzee, gorilla, orangutan, or gibbon) --called //also anthropoid, anthropoid ape// =**B**=
 * Affliative (in the behavioral context)- Nonagonistic body contact, or invitation for body contact by staring, approaching, and/or gesturing to another; greeting behaviors such as between individuals who were not previously in contact and can include pant grunt, embrace, head bob, and/or gentle touch.
 * Agnostic(in the behavioral context)- Individual performs or receives aggressive behaviors such as bark, grunt, chase, hit/punch, bite, flee, or scream; situations where no clear agonistic behaviors are present but there is clear conflict; reconciliation and support behaviors such as two individuals engaging in friendly body contact while at least one of them seems distressed, frightened, or hurt can be between either aggressor and victim, or between victim and third individual, as well as individual supporting another who is involved in agonism with opponent.
 * Anthropoid Ape- a: monkey; especially: one of the larger tailless or short tailed Old World
 * Brachiomanual: Arm guestures (or in this study all limb movement, arms and legs).
 * Broca's area: A region of the brain dealing with the productinon of speech (M-W).
 * Brodmann's area: A region of the brain that is the ape homologue of Broca's area.

=**C**=
 * Chimpanzee-noun: a large, somewhat arboreal anthropoid ape, Pan troglodytes, ofequatorial Africa, having a brown-to-black coat, a relativelyhairless face with a muzzle, prominent ears, and handsadapted for knuckle-walking, noted for its intelligence andhumanlike behavior: now greatly reduced in number andthreatened with extinction in the wild.

=**F**= =** G **=
 * Food-(in the behavioral context)-gathering and/or eating food; anticipating food when provision is imminent, as evident from arrival of caretakers with foo; competing for food by way of grabbing, pulling, picking up parts, and/or begging; simply a keen interest in other's food by way of staring or peering; nursing.
 * Free Brachiomanual Gestures- manual communication without touching another individual or substrate.
 * Gestures-communication by means of hands, feet or limbs (that serves no locomotive purpose.)
 * Groom (in the behavioral context)- using one or both hands individual pushes another's hair back with the thumb or index finger and picks at the exposed skin; can give or receive or perform on self; invitation to groom by staring, approaching, and/or signaling.

=H=  2. corresponding in structure and in origin, but not necessarilyin function: The wing of a bird and the foreleg of a horse are homologous 3. having the same alleles or genes in the same order of arrangement: homologous chromosomes. 4. Chemistry. of the same chemical type, but differing by afixed increment of an atom or a constant group of atoms: //Methyl and ethyl alcohols are homologou s. //5. Immunology. pertaining to an antigen and its specific antibody. =**L**=
 * Homolgies- traits directly inherited from the common ancestors of apes and Bonobos rather than innovations after the evolution and branching off of primates began. Also refers to shared evolutionary ancestry. Ex. Similar evolutionary ancestry between bonobos and humans.
 * Hominoidea-noun: anthropoid apes and human beings
 * Homologous-adjective:1. having the same or a similar relation; corresponding, as in relative position or structure.
 * Locomotion-(in the behavioral context)- Individual walks with, runs with, or follows another, or walks or runs away from another; also includes signaling to another to induce movement with or away from signaler.
 * Lexical: Relating to the words of a language (The Free Dicitonary).
 * Lexical retrieval: the ability to remember words

=**M**=
 * Multimodal- A combination of two or more different forms of communication.

=O= =P=
 * Orofacial: Facial guestures.
 * Proxy-noun: plural proxies- 1.The agency function, or power of a person authorized to act as a substitute for another.
 * Play-(in the behavioral context)- Individuals wrestle, chase, and.or tickle each other in nonagonistic, relaxed manner; invitation to play by running toward and away from another and/or communicative signals

__**A. Introduction**__ __**B. Results**__ 1. Species Typical Gesture Profiles 2. Context Specificity of Signals: As predicted, vocal/facial signals were more dependent on the context than gestures, at least in the groups as a whole. 3. Behavorial Contexts 4. Stability of Signal Context 5. Responsiveness to Multimodal Signals __**C. Discussion**__
 * Apes often make gestures to communicate, which is thought to be similar to the begining of human language evolution.
 * Purpose of the study: To compare gestures to facial/vocal signals in bonobos (closely releated to humans) and chimpanzees, as well as to see if gestures are as context-dependent as other forms of ACSs.
 * Bonobos are able to combine guestures and facial/vocal signs to give greater meaning to the reciever(s) of their messages.
 * Early human communication is thought to be gestural.
 * Primates: Commonly use vocalizatioins, orofacial movements, body postures, and locomotion patterns to communicate.
 * Hominoidea: Commonly use free (not touching anything) guestures. This may be a sign of a move towards a more flexible and intentional mode of communication. These guestures can often be contextually bound. For example extending a hand. Depending on the situation it can mean "help me" if the signaler is in a fight, or "give me some of your food" if used during mealtime.
 * Movement in forearm, hand, wrist, fingers, legs, and feet.
 * Non-tactile and directed at another party or individual.
 * Tactile action can be guestural as long as it is brief and does not force the recipient of the touch into a desired action.
 * Play guestures were not included in this study except for guestures that initiated play.
 * Chimpanzees: more likely to //arm raise//, //hard touch//, and //dab//
 * Bonobos: more likely to //reach out down//, //reach out up//, //gentle touch//, and //slap ground//
 * Facial and vocal displays are more context bound than gestures.
 * Gestural flexibility hypothesis: signals produced by gestures should vary more than those produced by facial/vocal displays.
 * "Cultural variation: changes between groups of the same species with regards to signals.
 * Statistical analysis proves that facial/vocal symbols in bonobos were less changeable than gestures, since they had strong correlations to the context they were produced in (ex: one call only used for predators, etc). The hypothesis did not apply to chimpanzees, however; both their facial/vocal and gestural showed the same level of malleability.
 * Hypothesis: Multimodal communciation is more likely to produce a response.
 * In bonobos, multimodal signals were more likely to produce a response. In chimpanzees, they were no more likely than gestures alone to illicit a response.
 * Data supports gestural flexibility hypothesis.
 * Gestures
 * Seem less tied to emotions.
 * Young in evolution, probably because they require more brain control.
 * Less related across species.
 * Can be modified, conventionalized, and socially transmitted.
 * When bonobos combine gestures with facial expressions and vocal signals, they are more likely to get a response.
 * Multimodal ccommunication in bonobos is used sparingly. Could this mean that they reserve this mode of communication for when they need to communicate in a more deliberate, specific manner?

1. All data is from videotaped spontaneous behavior of captive apes 2. Gestures only counted towards results if they initiated contact, not if they were in the middle or end of an ongoing interaction. This restricted the quantity of the data but increased reliability.
 * __D. Methods__**
 * Subjects & Sites: 2 groups of 17 chimpanzees each and 2 groups of bonobos, one with 6 and the other with 7
 * Data Collection: started at 8 am and continued observing through feeding times and into the afternoon, included video sequences and baseline focal data
 * Coding Protocol: distinguished 31 different gestures, 18 facial/vocal signals, and 7 context types