Conclusion and References

5. Conclusion

We have introduced gestures in this topic of language evolution by exploring the different types of gestures, namely representational gestures, beat gestures and interactive gestures. In both infants and animals, imitating gestures is a way of learning how to communicate. Infants imitate to match what they see to what they do, while animals imitate as a form of social learning – by imprinting behaviors from an adult or peer to a child.

We also discussed about the popular Gestural Theory in the evolution of language, comparing that to the Theory of Language in terms of human communication. To sum up, The Gestural Theory provides a wide range of evidence accounting for the precedence of gestures over speech in the origins of language, garnering support and backing by many linguists and evolutionists. For example, neurophysiological evidence provided by mirror neurons supports the development of language from gestures. The vast amount of research done on gesturing in animal communication and the homology in mirror systems in the brain have supported that gestures served as an important means of primate communication before vocalizations ultimately led to speech. Gestures in animals, in particular non-human primates, are hence important in providing evidence of this form of primate communication before vocalizations were possible. Studies done on both apes and monkeys support the communicative functions of gesturing in animals, with its wide variety of gesture repertoires providing clues to speech repertoires today.

The case study on Nicaraguan Sign Language (NSL) provides an interesting insight on how home sign systems and gestures have resulted in the birth of a new language across two cohorts of children, following the formation of a deaf community in Nicaragua. It shows just how impactful gestures and signs are in our world, where languages are constantly evolving over time.

We hope you have gained greater insight on gestures as a mode of communication present not only before vocalization and speech, but have also been integrated into our communication systems today as a supplement to speech.

6. References

Alibali, M. W., Heath, D. C., & Myers, H. J. (2001). Effects of visibility between speaker and listener on gesture production: Some gestures are meant to be seen. Journal of Memory and Language, 44(2), 169-188. doi:10.1006/jmla.2000.2752

Arbib, M. A., Liebal, K., & Pika, S. (2008). Primate vocalization, gesture, and the evolution of human language. Current Anthropology, 49(6), 1053-1076. doi:10.1086/593015

Bekkering, H., Wohlschlager, A., & Gattis, M. (2000). Imitation of gestures in children is goal-directed. Quarterly Journal of Experimental Psychology Section A, 53(1), 153-164. doi:10.1080/027249800390718

Brooks-Pollock, T. (2014). The 66 gestures which show how chimpanzees communicate. Retrieved April 2, 2015, from http://www.telegraph.co.uk/news/science/10945811/The-66-gestures-which-show-how-chimpanzees-communicate.html

Corballis, M. C. (2002). From hand to mouth, the origins of language. Princeton: Princeton University Press.

Fay, J. M. (1989). Hand-clapping in western lowland gorillas (Gorilla gorilla gorilla). Mammalia, 53(3).

Fogassi, L., & Ferrari, P. F. (2004). Mirror neurons, gestures and language evolution. Interaction Studies, 5(3), 345-363. doi:10.1075/is.5.3.03fog

Gillespie-Lynch, K., Greenfield, P. M., Feng, Y., Savage-Rumbaugh, S., & Lyn, H. (2013). A cross-species study of gesture and its role in symbolic development: Implications for the gestural theory of language evolution. Frontiers in Psychology, 4.

Goodall, J. (1986). The Chimpanzees of Gombe: Patterns of behaviour. Cambridge: Belknap.

Hobaiter, C. & Byrne, R. W. (2014). The Meanings of Chimpanzees Gestures. Current Biology, 24(14), pp. 1596-1600.

Kohler, E., Keysers, C., Umilta, M. A., Fogassi, L., Gallese, V., & Rizzolatti, G.(2002). Hearing Sounds, Understanding Actions: Action Representation in Mirror Neurons. Science, 297, pp. 846-858.

Kimura, D. (1993). Neuromotor mechanisms in human communication. Oxford: Oxford
University Press.

Kummer, H. (1968). Social organization of hamadryas baboons. Chicago: University of Chicago Press.

Maestripieri, D. (1999). Primate social organization, gestural repertoire size, and communication dynamics. The origins of language: What nonhuman primates can tell, pp. 55-77.

McLane, J. (1996). The voice on the skin: Self-mutilation and merleau-ponty’s theory of language. Hypatia, 11(4), 107-118.

McNeill, D. (1985). So you think gestures are nonverbal? Psychological Review, 92(3), 350-371. doi:10.1037//0033-295X.92.3.350

Meltzoff, A. N., & Moore, M. K. (1977). Imitation of facial and manual gestures by human neonates. Science, 198(4312), 75-78. doi:10.1126/science.897687
Morgan, G., & Kegl, J.(2006). Nicaraguan Sign Language and Theory of Mind: the issue of critical periods and abilities. Journal Of Child Psychology & Psychiatry, 47(8), 811-819. doi:10.1111/j.1469-7610.2006.01621.x

Ogden, J. & Schildkraut, D. (1991). Compilation of gorilla ethograms. Atlanta: Gorilla Behavior Advisory Group.

Paget, R. A. S. (1963). Human speech: Some observations, experiments and conclusions as to the nature, origin, purpose and possible improvement of human speech.

Parnell, R. J., & Buchanan-Smith, H. M. (2001). Animal behaviour: An unusual social display by gorillas. Nature, 412(6844).

Pika, S. (2008). Gestures of apes and pre-linguistic human children: Similar or different? First Language, 28(2), 114-140. doi:10.1177/0142723707080966

Redshaw, M. & Locke, K. (1976). The development of play and social behaviour in two lowland gorilla infants. Journal of the Jersey Wildlife Preservation Trust, Thirteenth Annual Report, pp. 71-86.

Senghas, A., & Coppola, M. (2001). Children Creating Language: How Nicaraguan Sign Language Acquired a Spatial Grammar. Psychological Science (Wiley-Blackwell), 12(4),

Senghas, A., Kita, S., & Özyürek, A. (2004). Children Creating Core Properties of Language: Evidence from an Emerging Sign Language in Nicaragua. Science, 305(5691), 1779-1782.

Skoyles, J. R. (2000). Gesture, language origins, and right handedness. Psycoloquy, 11(24).

Zentall, T. R., & Akins, C. (2001). Imitation in animals: Evidence, function, and mechanisms. Cybernetics and Systems. doi:10.1080/019697201300001812

Part IV: Nicaraguan Sign Language

5. From Simple Signs to a Full Sign Language: The Nicaraguan Sign Language

nsl1 — How do individual simple signs become a full-blown language over time?

A particular case study that shows the development of language evolution is the emergence of the Nicaraguan Sign Language. The Nicaraguan Sign Language (NSL) was created through the interaction between previously isolated deaf people and subsequent cohorts of children exposed to this initial gestural communication (Morgan & Kelg, 2006). With the sequential cohorts of learners, the community has shown the systemization of its grammar over the past years. According to Senghas & Coppola (2001), language systematicity in NSL stems from children aged ten and younger, indicating that young children collectively possess the capacity to learn and create language. This is substantiated by one of NSL’s structural complexity feature, spatial modulation.

nsl2-300x188 — One of the signs for “Nicaragua”.

Spatial modulations are the building blocks of grammars in sign languages. In developed sign languages, spatial modulations perform functions that provide grammatical relationships like subject and object, deictic, locative, temporal information etc. (Senghas & Coppola, 2001). Senghas & Coppola’s study (2001) aimed to understand the role of spatial modulations in terms of prevalence, function and production rate in NSL grammar systematicity. The results showed that spatial modulations are signed frequently in the early-exposed signers of the second cohort than those of the first cohort, revealing that the second NSL cohort did not merely reproduce the language by their predecessors, but also modified the language as they learned it. Spatial modulations are also found to be the medium of enabling long-distance grammatical relationships among words in NSL, similar to other established sign languages. Additionally, they are communicated with an increase in overall fluency.

In Senghas et al.’s research on NSL (2004), they focused on two of Hockett’s design features of a language: discreteness and combinatorial patterning. These properties arose naturally as a product of the language-learning mechanism although they were not available in the surrounding environment. They found that there was a predisposition for linear sequencing and segmental approaches to bundles of information.

For example, to describe complex motions, like rolling down a hill, participants of the second NSL cohort signed the manner and path sequentially whereas the first cohort articulated the manner and path simultaneously. According to Senghas et al. (2004), when representations express manner and path separately, the iconicity of the simultaneous movement is no longer clear. However, this combinatory change in communication, which allows for more potential and ambiguity, denotes a shift from gestural to more language like expressions in NSL Such combinatory changes that enable the production of infinite utterances from a finite set of elements, explain various core, universal properties of mature languages like how discrete elements (words and morphemes) are combined to form hierarchically organized constructions (phrases and sentences). These changes are further reinforced in the newer cohorts. Likewise, word order regularities driven by children are well documented in creoles and similar sequencing elements are also identified.

nsl3-300x168 — Simultaneously manner and path vs. Sequential manner and path in NSL

Part III: Speech Before Gestures – Is It Possible?

4. Speech Before Gestures – Is It Possible?

In many studies of child acquisition of language, gestures pave the way for children’s early nouns. One simple illustration of this is a child producing a deictic gesture for a particular object, for example a dog, approximately 3 months before they are able to verbally label it (Iverson & Goldin-Meadow, 2005). However, does this always mean that gestures precede speech?

In a Özçalışkan et al.’s (2013) study conducted on iconic gestures and children’s early verbs, it was revealed that the use of deictic gestures begins in children at 10 months, preceding the production of verbs in children by six months. However, the onset of iconic gestures conveying action meanings follows, rather than precedes the child’s first verbs. Examples of iconic gestures include flapping the arms to depict a bird flying or moving an empty fist forcefully forward to convey the meaning of “throwing”. Unlike pointing gestures, iconic gestures involve the representation of referent with a particular symbol, thus, imposing greater cognitive demands than deictic gestures. Eventually, gestures have come to complement vocalized ideas. These dynamic iconic gestures hence suggests the need for a inner verbal system before the communication of the an idea, be it in gestures or speech.

The findings of the study also suggest that children use gestures to expand their repertoire of action meanings, but only after they have begun to acquire the verb system that is underlying their language. Perhaps the theory suggesting that gestures precede speech only holds for gestures of less demanding cognitive functions of the brain, such as deictic gestures. Acquisition of verb and nouns is ultimately crucial to producing meaningful gestures that express relational concepts. Therefore, although the investigation of speech occurring before gestures seems hardly possible, it is arguable that an early inner verbal system that is fundamental for communication may have preceded gestures in human communication, as shown in studies conducted on children’s early verbs.

chimp-300x187 — Gestures as primate communication – before speech. Photo: Dr. Catherine Hobaiter

Part II: Gestural Communication in Animals

3. Gestural Communication in Animals

There are numerous studies that support that non-human primates, who are of closest relation to humans are able to gesture as part of their communication systems. The pioneering studies of Goodall (1986) and Kummer (1968) observed different gestures used by monkeys and apes.

The studies of gestural communication in apes both in captivity and in the wild reveal the following:

The use of communicative gestures is common across the species,
There is considerable variability in gesture repertoire from group to group,
Gestures are used flexibly in different contexts, depending on the behavior of the recipient.

Gesturing by primates is argued to be partially genetic, with apes performing gestures that are characteristic of their species even without prior observation of the gesture. An evidence of this is the “chest beat”, a display of threat, being performed by two gorillas that have not witnessed the performance of this gesture before (Redshaw & Locke, 1976). Similarly, chimpanzees from peer groups that essentially had no opportunity to observe older conspecific develop many of the same play gestures performed by individuals from a more natural group composition (Berdecio & Nash, 1981). Hence, the Gestural Theory suggests the importance and intrinsicality of gestures in primate communication, holding that gestures were the precursors to language and communication.

gorilla-267x300 — A gorilla’s gesture of “chest beat” is an intrinsic part of primate communication that conveys a message of threat.

3.1 Gestural Repertoires in Non-Human Primates

Pika (2008) explained that primates are able to produce different types of gestures, namely,

Auditory gestures – dependent on the sound produced
Tactile gestures – dependent on physical contact
Visual gestures – dependent on visual information

Gestural repertoires vary depending on the individual’s age, sex and group affiliation. For example, there are at least twenty different gestures observed among siamangs, a group representative of small apes and gibbons. Such gestures include “embrace” and “offer body part”. The production of species-typical gestures may be due to genetic dispositions (Arbib et al., 2008), as chimpanzees from peer groups that had no opportunity to observe older chimpanzees developed many of the same play gestures as individuals from relative groups.

3.2 Monkeys and Apes

Pika’s research (2008) revealed that monkeys are able to notify fellow members in the family. This was determined when one monkey had eye-to-eye close contact with another monkey before moving onto another task. It is possible that the first monkey was emphasizing a point to the other monkey. The research also revealed that monkeys were able to attract a fellow monkey’s attention by conducting the action of slapping the ground. Different species of monkeys have also been found to use different varieties of manual gestures and postures, varying as a function of social rank and contexts (Maestripieri, 1999).

Pika (2008) also showed that apes produced communicative gestures that were specific to its species. Ogden & Schildkraut (1991) suggested that gorillas are able to produce a combination of auditory and visual gestures. Some specific gestures include the splash display (Parnell & Buchanan-Smith, 2001) and the hand clapping (Fay, 1989). Arbib et al. (2008) revealed that gorillas in captive are able to utilize a variety of at least 30 different tactile, visual and auditory gestures.

A recent study conducted by the University of St Andrews also records up to 66 different gestures that show how chimpanzees communicate, such as the tapping of another chimpanzee to indicate ‘stop that’ and the raising of an arm to indicate ‘give me that’ (Brooks-Pollock, 2014). Even with such a “gestural lexicon” on chimpanzees created, many variances were observed in the communication of a certain meaning, suggesting that different groups of monkeys develop their respective sets of gestural repertoires. Nonetheless, Hobaiter & Bryne (2014) explained that just with human words, some gestures by the chimpanzees have several senses, but the meanings remain the same irrespective of who uses them.

This information on the gestural system in non-human primates suggests the primitive origins of gestures as a form of communication even with the absence of speech, providing additional insight to the gestural-first theory in the study of evolutionary linguistics, particularly in the recent years.

Here’s a video that shows how the “chest beat” (as performed innocently by the little girl) has agitated a gorilla, due to the gesture signifying an act of dominance and aggression:

Part I: Gestural Theory

2. Gestural Theory

McLane (1996) described gesturing as a means to communicate an experience. While this might encourage a person to speak, there are times where speech just simply cannot be produced, for example, in situations such as taboo topics or situations where the mind does not have words to express what is intended. Based on the research she conducted on trauma patients, McLane suggests that physical and psychological trauma situations are examples in which communication by speech is challenging. As a result, people may turn to gestures as a way of conveying their message.

The theory of language suggests that people use language as an extension of us due to a need to communicate our experiences, in other words, people have the need to share about things that had happened to them (McLane, 1996). This is what supports communication, as people “communicate to hear and to be heard”. As McLane (1996) had mentioned, “We will say our lives in order to have or live our lives” (p. 107). This quote illustrates that in order to experience life, there is a need to express the experiences.

The Gestural Theory states that human language was developed from gestures that were a primitive form of communication, as opposed to the vocal signals that might have been adopted by non-human primates. According to Gillespie-Lynch et al. (2013), bipedalism might be an influencing factor on gesturing, as walking on two feet allows both hands to be available for gesturing. To date, this theory that hypothesizes that gestures preceded speech in human language remains a popular topic of discussion by both evolutionists and linguists. Numerous anatomical and neurophysiological data have supported the stance that human language had evolved from gestural communication (Paget, 1963; Corballis, 2002; Kimura, 1993).

We will be focusing on the Gestural Theory to further our discussion on gestures in the evolution of language.

2.1 Imitating Gestures

Through the years, animals and humans have learned from imitation. This method encourages more efficiency in learning as it bypasses the need for time-consuming trial and error method as a form of learning. This is despite humans making conscious efforts to steer away from this mentality especially when it comes to creating new innovations or starting something new, all of which requires some measure of trial and error. In contrast, a colloquial phrase “Monkey See, Monkey Do” illustrating the imitation of one another in animals is frequently used.

In humans, imitation is most commonly seen among children. A study by Meltzoff & Moore (1977) suggests that infants can do so from the as early as twelve days old, from the mimicking of actions to facial gestures. The research also illustrates that imitation occurs when infants attempt to match what they see (visual input) to their actions (motor output). Another proposed theory is that imitation in children is goal orientated, meaning infants are assumed to react by imitation to a stimulus.

A series of experiments conducted by Bekkering et al. (2000) showed that infants react in the following ways:

Towards an object – when reaching to touch something
Towards an agent – when reaching towards an interactive object such as an adult’s fingers
Towards a movement path – when reaching towards and along in a given direction
Towards salient features – when reaching towards gestures such as arms crossing.

Similarly, imitation is frequently seen in animals. Although it is less apparent as compared to gestures, animals seem to imitate more in commonly in terms of behavior. Zentall & Akins (2001) speculated in their study that one determining factor for imitation to occur could be the need for social learning among animals. Imprinting is seen as a social learning method that describes how one animal imitates the other. This form of phase-sensitive learning is independent of the consequences of the behavior. One common example is how ducklings follow after their mother duck as they move from one place to another. This form of social learning in animals is also hypothesized by Lorenz (1935) to have a critical period of 13 to 16 hours after hatching, just as language acquisition in humans follow the Critical Age Hypothesis.

Ducks — Like languages, imprinting as a form of social learning imitation method in animals, is hypothesized to have a critical period for learning.

Hence, gesturing can be seen through the imitation of actions by both animals and humans, suggesting the presence of an indirect mode of communication that does not require speech.

2.2 Mirror Neurons

Neurophysiological evidence supports the theory that gestural communication serves as the precursor of human language. Fogassi & Ferrari (2014) investigated the motor cortex in monkeys, also known as area F5, where mirror neurons are located. These mirror neurons are activated when an animal executes or observes a goal-related action performed by another. According to Skoyles (2000), mirror neurons are able to explain how signs are produced and interpreted. Mirror neurons are also able to support the emergence of spoken language after the demise of the primitive gesturing systems as a means of communication.
According to research done by Gallese et al. (1996) and Rizzolatti et al. (1996), these visuomotor neurons (mirror neurons) became activated in the area F5 of the brain when monkeys perform hand actions, or when they observe another individual producing a similar action.

There are two categories that depict the connection between mirror neurons and communication.

Audiovisual mirror neurons becomes activated when monkeys not only observe, but also hear the sound of an action (Kolher et al, 2002)
- For example, a monkey would respond to the sound of a peanut being broken open when the action is either observed, heard, or both. However, a monkey would not respond to the vision or sound of another irrelevant action.
Mouth mirror neurons become activated when a monkey observes and executes mouth ingestive actions such as biting, sucking, licking etc.
- For example, a monkey would respond and react in the presence of food or in anticipation of food.

The activation of the mirror neurons seems to have a direct correlation to the seen and produced actions. Hence, there is a possible impact on the interpretation of actions by action observation and execution.

monkey2 — Monkey See, Monkey Do? Fogassi et al. has revealed that mirror neurons in monkeys’ brains are activated when observing and executing both hand and mouth actions, suggesting its responsibility for the emergence of speech during evolution.

Fogassi et al. (2004) suggests that the properties of mirror neurons are part of the basic neural mechanism that associates gestures with meaningful sounds. This also suggests that this pre-adaptation subsequently led to an emergence of speech.

In that case, how do mirror neurons link to the emergence of language in humans?
Skoyles (2000) explains that mirror neurons are found in an area known as area 44, located in the Broca’s area. Broca’s area is a region in the frontal lobe of the left hemisphere of the brain, responsible for language processing and speech production. Both area F5 and Broca’s area were activated during the observation of hand and mouth actions based on demonstrations by brain imaging experiments. With this homology of area 44 near Broca’s area and F5 region (where mirror neurons in monkeys were located), Fogassi & Ferrari (2004) proves the existence of a mirror system for action understanding, just like the activation of mirror neurons in monkeys.

brains — Homology of area 44 in humans (left) and F5 region in a monkey’s brain shows that humans have a mirror system of understanding based on action observation and executive, similar to that of the dyadic communication in monkeys.

These observations in the cortical region precursor of Broca’s area, area 44, revealed its capacity to execute and understand hand and mouth actions, indicating primitive forms of dyadic communication (Fogassi & Ferrari, 2004). These homologies found based on neurophysiological evidence supports the gestures-first hypothesis – that human language evolved from a gesture performance and understanding system implemented a mirror neurons, allowing language to encompass features such as action-understanding, imitation-learning, and simulation of others’ behaviors as communication evolved over time.

Chapter 7 – Natural laboratories for language evolution: Pidgins, Creoles, and Sign Language

2015: Esther Wong Rui Li, Low Lin Yi, Lyn
2014: Jessica Chua, Lee Mui Wei, Lew Xu Hong

Hi there! Welcome to Gestures, Speech and Sign Language in Language Evolution. In this chapter, you will learn more about gestures and its role in the evolution of language.

1. Introduction to Gestures

Gestures are a type of non-verbal communication used by a speaker to aid communication. McNeill (1985) interprets gestures as the second channel of communication, in which the first channel of communication is actual speech, thus implying that gestures add on to speech production. Alibali et al. (2001) conducted a series of experiments to see whether speakers would use gestures differently depending on the need to see gestures when communicating. The results revealed that speakers would continue to use gestures when communicating regardless of the listener’s visibility of their gestures.

In this chapter, we will discuss the role of gestures in language evolution by focusing on the Gestural Theory and how gestures have contributed to an emergence of a new sign language today.

1.1 Representational Gestures

Representational gestures are gestures that carry some form of speech content. This form of gestures is reliant on the visibility of the gestures, in other words, the listener has to be in the line of sight of the speaker for the message to be conveyed successfully. There is also a higher frequency of use of representational gestures if the speakers are able to see their listeners during communication (Alibabi et al., 2001).
What was interesting was that speakers still produced representational gestures when communicating even when they could not physically see their listeners, suggesting that representational gestures are a part of speech production. The visibility of the listener merely varies the frequency of gesture production, but does not affect gesture production. Hence, this form of gesturing has become a subconscious form of communicating ideas.

Iconic gestures are a form of representational gesture that refer to a concrete referent. For example, a kicking motion with the foot conveys the meaning of the action “to kick”. Speakers use iconic gestures to emphasize what they are talking about, as iconic gestures refers specifically to an action or object that the speaker intends to communicate.

1.2 Beat Gestures

Beat gestures are gestures that do not carry any speech content. They convey non-narrative content and are more in tune with the rhythm of speech. According to Alibali et al. (2001), beat gestures are used regardless of whether the speaker could see the listener or not. Therefore, beat gestures accentuate the topic that is being conveyed without directly referring to the topic, emphasizing certain words and phrases during speech.

Still unsure about what beat gestures are? Here’s a video to show an example of beat gestures!

Interactive Gestures

Interactive gestures are gestures that are a combination of both representational and beat gestures. This form of gestures is commonly seen in dialogues that consists of a back and forth communication flow between speakers.