Gesture

A gesture is a form of non-verbal communication or non-vocal communication in which visible bodily actions communicate particular messages, either in place of, or in conjunction with, speech. Gestures include movement of the hands, face, or other parts of the body. Gestures differ from physical non-verbal communication that does not communicate specific messages, such as purely expressive displays, proxemics, or displays of joint attention. Gestures allow individuals to communicate a variety of feelings and thoughts, from contempt and hostility to approval and affection, often together with body language in addition to words when they speak.

Gesture processing takes place in areas of the brain such as Broca's and Wernicke's areas, which are used by speech and sign language. In fact, language is thought to have evolved from manual gestures. The theory that language evolved from manual gestures, termed Gestural Theory, dates back to the work of 18th-century philosopher and priest Abbé de Condillac, and has been revived by contemporary anthropologist Gordon W. Hewes, in 1973, as part of a discussion on the origin of language.

Study on gestures
Gestures have been studied throughout the centuries from different view points. During the Roman Empire, Quintilian studied in his Institution Oratoria how gesture may be used in rhetorical discourse. Another broad study of gesture was published by John Bulwer in 1644. Bulwer analyzed dozens of gestures and provided a guide on how to use gestures to increase eloquence and clarity for public speaking. Andrea De Jorio published an extensive account of gestural expression in 1832.

Categories of gestures


Although the study of gesture is still in its infancy, some broad categories of gestures have been identified by researchers. The most familiar are the so-called emblems or quotable gestures. These are conventional, culture-specific gestures that can be used as replacement for words, such as the handwave used in the US for "hello" and "goodbye". A single emblematic gesture can have a very different significance in different cultural contexts, ranging from complimentary to highly offensive The page List of gestures discusses emblematic gestures made with one hand, two hands, hand and other body parts, and body and facial gestures.

Another broad category of gestures comprises those gestures used spontaneously when we speak. These gestures are closely coordinated with speech. The so-called beat gestures are used in conjunction with speech and keep time with the rhythm of speech to emphasize certain words or phrases. These types of gestures are integrally connected to speech and thought processes.

Other spontaneous gestures used during speech production known as iconic gestures are more full of content, and may echo, or elaborate, the meaning of the co-occurring speech. They depict aspects of spatial images, actions, people, or objects. For example, a gesture that depicts the act of throwing may be synchronous with the utterance, "He threw the ball right into the window." Such gestures that are used along with speech tend to be universal. For example, one describing that he/she is feeling cold due to a lack of proper clothing and/or a cold weather can accompany his/her verbal description with a visual one. This can be achieved through various gestures such as by demonstrating a shiver and/or by rubbing the hands together. In such cases, the language or verbal description of the person does not necessarily need to be understood as someone could at least take a hint at what's being communicated through the observation and interpretation of body language which serves as a gesture equivalent in meaning to what's being said through communicative speech.

Studies affirm a strong link between gesture typology and language development. Young children under the age of two seem to rely on pointing gestures to refer to objects that they do not know the names of. Once the words are learned, they eschewed those referential (pointing) gestures. One would think that the use of gesture would decrease as the child develops spoken language, but results reveal that gesture frequency increased as speaking frequency increased with age. There is however a change in gesture typology at different ages, suggesting a connection between gestures and language development. Children most often use pointing and adults rely more on iconic and beat gestures. As children begin producing sentence-like utterances, they also begin producing new kinds of gestures that adults use when speaking (iconics and beats). Evidence of this systematic organization of gesture is indicative of its association to language development.

Gestural languages such as American Sign Language and its regional siblings operate as complete natural languages that are gestural in modality. They should not be confused with finger spelling, in which a set of emblematic gestures are used to represent a written alphabet. American sign language is different from gesturing in that concepts are modeled by certain hand motions or expressions and has a specific established structure while gesturing is more malleable and has no specific structure rather it supplements speech. We should note, that before an established sign language was created in Nicaragua after the 1970s, deaf communities would use "home signs" in order to communicate with each other. These home signs were not part of a unified language but were still used as familiar motions and expressions used within their family—still closely related to language rather than gestures with no specific structure. This is similar to what has been observed in the gestural actions of chimpanzees. Gestures are used by these animals in place of verbal language, which is restricted in animals due to their lacking certain physiological and articulatory abilities that humans have for speech. Corballis (2009) asserts that "our hominin ancestors were better pre-adapted to acquire language-like competence using manual gestures than using vocal sounds." This leads to a debate about whether humans, too, looked to gestures first as their modality of language in the early existence of the species. The function of gestures may have been a significant player in the evolution of language.

Social significance
Gestures, commonly referred to as “body language,” play an important role in industry. Proper body language etiquette in business dealings can be crucial for success. However, gestures can have different meanings according to the country in which they are expressed. In an age of global business, diplomatic cultural sensitivity has become a necessity. Gestures that we take as innocent may be seen by someone else as deeply insulting. The following gestures are examples of proper etiquette with respect to different countries’ customs on salutations: In the United States, “a firm handshake, accompanied by direct eye contact, is the standard greeting. Direct eye contact in both social and business situations is very important.” In the People’s Republic of China, “the Western custom of shaking a person's hand upon introduction has become widespread throughout the country. However, oftentimes a nod of the head or a slight bow will suffice.” In Japan, “the act of presenting business cards is very important. When presenting, one holds the business card with both hands, grasping it between the thumbs and forefingers. The presentation is to be accompanied by a slight bow. The print on the card should point towards the person to which one is giving the card.” In Germany, “it is impolite to shake someone's hand with your other hand in your pocket. This is seen as a sign of disrespect” In France, “a light, quick handshake is common. To offer a strong, pumping handshake would be considered uncultured. When one enters a room, be sure to greet each person present. A woman in France will offer her hand first.”

Gestures are also a means to initiate a mating ritual. This may include elaborate dances and other movements. Gestures play a major role in many aspects of human life. Gesturing is probably universal; there has been no report of a community that does not gesture. Gestures are a crucial part of everyday conversation such as chatting, describing a route, negotiating prices on a market; they are ubiquitous. Additionally, when people use gestures, there is a certain shared background knowledge. We use similar gestures when talking about a specific action such as how we gesture the idea of drinking out of a cup. When an individual makes a gesture, another person can understand because of recognition of the actions/shapes. Gestures have been documented in the arts such as in Greek vase paintings, Indian Miniatures or European paintings.

Gestures play a central role in religious or spiritual rituals such as the Christian sign of the cross. In Hinduism and Buddhism, a mudra (Sanskrit, literally "seal") is a symbolic gesture made with the hand or fingers. Each mudra has a specific meaning, playing a central role in Hindu and Buddhist iconography. An example is the Vitarka mudra, the gesture of discussion and transmission of Buddhist teaching. It is done by joining the tips of the thumb and the index together, while keeping the other fingers straight.

Neurology
Gestures are processed in the same areas of the brain as speech and sign language such as the left inferior frontal gyrus (Broca's area) and the posterior middle temporal gyrus, posterior superior temporal sulcus and superior temporal gyrus (Wernicke's area). It has been suggested that these parts of the brain originally supported the pairing of gesture and meaning and then were adapted in human evolution "for the comparable pairing of sound and meaning as voluntary control over the vocal apparatus was established and spoken language evolved". As a result, it underlies both symbolic gesture and spoken language in the present human brain. Their common neurological basis also supports the idea that symbolic gesture and spoken language are two parts of a single fundamental semiotic system that underlies human discourse. The linkage of hand and body gestures in conjunction with speech is further revealed by the nature of gesture use in blind individuals during conversation. This phenomenon uncovers a function of gesture that goes beyond portraying communicative content of language and extends David McNeill's view of the gesture-speech system. This suggests that gesture and speech work tightly together, and a disruption of one (speech or gesture) will cause a problem in the other. Studies have found strong evidence that speech and gesture are innately linked in the brain and work in an efficiently wired and choreographed system. McNeill's view of this linkage in the brain is just one of three currently up for debate; the others declaring gesture to be a "support system" of spoken language or a physical mechanism for lexical retrieval.

Because of this connection of co-speech gestures--a form of manual action--in language in the brain, Roel Willems and Peter Hagoort conclude that both gestures and language contribute to the understanding and decoding of a speaker's encoded message. Willems and Hagoort's research suggest that "processing evoked by gestures is qualitatively similar to that of words at the level of semantic processing." This conclusion is supported through findings from experiments by Skipper where the use of gestures led to "a division of labor between areas related to language or action (Broca's area and premotor/primary motor cortex respectively)." The use of gestures in combination with speech allowed the brain to decrease the need for "semantic control." Because gestures aided in understanding the relayed message, there was not as great a need for semantic selection or control that would otherwise be required of the listener through Broca's area. Gestures are a way to represent the thoughts of an individual, which are prompted in working memory. The results of an experiment revealed that adults have increased accuracy when they used pointing gestures as opposed to simply counting in their heads (without the use of pointing gestures) Furthermore, the results of a study conducted by Marstaller and Burianová suggest that the use of gestures affect working memory. The researchers found that those with low capacity of working memory who were able to use gestures actually recalled more terms than those with low capacity who were not able to use gestures.

Although there is an obvious connection in the aid of gestures in understanding a message, "the understanding of gestures is not the same as understanding spoken language." These two functions work together and gestures help facilitate understanding, but they only "partly drive the neural language system."

Electronic interface
The movement of gestures can be used to interact with technology like computers, using touch or multi-touch popularised by the iPhone, physical movement detection and visual motion capture, used in video game consoles.