Animal languages are forms of communication between animals that show similarities to human language. [1] Animals communicate through a variety of signs, such as sounds and movements. Signing among animals may be considered a form of language if the inventory of signs is large enough. The signs are relatively arbitrary, and the animals seem to produce them with a degree of volition (as opposed to relatively automatic conditioned behaviors or unconditioned instincts, usually including facial expressions).
Many researchers argue that animal communication lacks a key aspect of human language, the creation of new patterns of signs under varied circumstances. Humans, by contrast, routinely produce entirely new combinations of words. Some researchers, including the linguist Charles Hockett, argue that human language and animal communication differ so much that the underlying principles are unrelated. [2] Accordingly, linguist Thomas A. Sebeok has proposed to not use the term "language" for animal sign systems. [3] However, other linguists and biologists, including Marc Hauser, Noam Chomsky, and W. Tecumseh Fitch, assert that an evolutionary continuum exists between the communication methods of animal and human language. [4]
Some experts argue the following properties separate human language from animal communication: [5]
Research with apes, like that of Francine Patterson with Koko [7] (gorilla) or Allen and Beatrix Gardner with Washoe [8] [9] (chimpanzee), suggested that apes are capable of using language that meets some of these requirements, including arbitrariness, discreteness, and productivity. [10]
In the wild, chimpanzees have been seen "talking" to each other when warning about approaching danger. For example, if one chimpanzee sees a snake, said chimpanzee may make a low, rumbling noise, signaling for all the other chimps to climb into nearby trees. [11] In this case, the chimpanzees' communication does not indicate displacement, as it is entirely contained to an observable event.
Arbitrariness has been noted in meerkat calls; bee dances demonstrate elements of spatial displacement; and cultural transmission has possibly occurred through language between the bonobos named Kanzi and Panbanisha. [12]
Claims that animals have language skills akin to humans, however, are extremely controversial. In his book The Language Instinct , [13] Steven Pinker illustrates that claims of chimpanzees acquiring language are exaggerated and rest on very limited or specious evidence. [13]
The American linguist Charles Hockett theorized that there are sixteen features of human language that distinguish human communication from that of animals. He called these the design features of language. The features mentioned below have so far been found in all spoken human languages, and at least one is missing from any other animal communication system.
Humans are able to distinguish real words from fake words based on the phonological order of the word itself. In a 2013 study, baboons were shown to have this skill as well. The discovery has led researchers to believe that reading is not as advanced a skill as previously believed, but instead based on the ability to recognize and distinguish letters from one another. The experimental setup consisted of six young adult baboons, and results were measured by allowing the animals to use a touch screen and select whether or not the displayed word was a real word, or a non-word such as "dran" or "telk". The study lasted for six weeks, with approximately 50,000 tests completed in that time. The researchers minimized common bigrams, or combinations of two letters, in non-words, and maximized them in real words. Further studies will attempt to teach baboons how to use an artificial alphabet. [17]
In a 2016 study, a team of biologists from several universities concluded that macaques possess vocal tracts physically capable of speech, "but lack a speech-ready brain to control it". [18] [19]
Among the most studied examples of non-primate languages are:
The effects of learning on auditory signaling in these animals is of interest to researchers. Several investigators have pointed out that some marine mammals appear to have the capacity to alter both the contextual and structural features of their vocalizations as a result of experience. Janik and Slater have stated that learning can modify vocalizations in one of two ways, by influencing the context in which a particular call is used, or by altering the acoustic structure of the call itself. [33] Male California sea lions can learn to inhibit their barking in the presence of any male dominant to them, but vocalize normally when dominant males are absent. [34] The different call types of gray seals can be selectively conditioned and controlled by different cues, [35] and the use of food reinforcement can also modify vocal emissions. A captive male harbor seal named Hoover demonstrated a case of vocal mimicry, but similar observations have not been reported since. Still shows that under the right circumstances pinnipeds may use auditory experience in addition to environmental consequences such as food reinforcement and social feedback to modify their vocal emissions.[ citation needed ]
In a 1992 study, Robert Gisiner and Schusterman conducted experiments in which they attempted to teach syntax to a female California sea lion named Rocky. [30] Rocky was taught signed words, then she was asked to perform various tasks dependent on word order after viewing a signed instruction. It was found that Rocky was able to determine relations between signs and words, and form basic syntax. [30] A 1993 study by Schusterman and David Kastak found that the California sea lion was capable of understanding abstract concepts such as symmetry, sameness and transitivity. This suggests that equivalence relations can form without language.
The distinctive sounds of sea lions are produced both above and below water. To mark territory, sea lions "bark", with non-alpha males making more noise than alphas. Although females also bark, they do so less frequently and most often in connection with birthing pups or caring for their young. Females produce a highly directional bawling vocalization, the pup attraction call, which helps mothers and pups locate one another. As noted in Animal Behavior, their amphibious lifestyle has made them need acoustic communication for social organization while on land.
Sea lions can hear frequencies between 100 Hz and 40,000 Hz, and vocalize from 100 to 10,000 Hz. [36]
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It is worth distinguishing "animal language" from "animal communication", although there is some comparative interchange in certain cases (e.g. Cheney & Seyfarth's vervet monkey call studies). [43] Animal language typically does not include bee dancing, bird song, whale song, dolphin signature whistles, prairie dog alarm calls, or the communicative systems found in most social mammals.[ citation needed ] The features of language as listed above are a dated formulation by Hockett in 1960. Through this formulation Hockett made one of the earliest attempts to break down features of human language for the purpose of applying Darwinian gradualism. Although an influence on early animal language efforts (see below), it is no longer considered the key architecture at the core of animal language research.[ citation needed ]
Animal language results are controversial for several reasons (for a related controversy, see also Clever Hans). Early chimpanzee work was executed using chimpanzee infants raised as if they were human; a test of the nature vs. nurture hypothesis.[ citation needed ] Chimpanzees have a laryngeal structure very different from that of humans, and it has been suggested that chimpanzees are not capable of voluntary control of their breathing, although better studies are needed to accurately confirm this. This combination is thought to make it very difficult for the chimpanzees to reproduce the vocal intonations required for human language. Researchers eventually moved towards a gestural (sign language) modality, as well as keyboard devices with buttons with symbols (known as "lexigrams") that the animals could press to produce artificial language. Other chimpanzees learned by observing human subjects performing the task.[ citation needed ] This latter group of researchers studying chimpanzee communication through symbol recognition (keyboard) as well as through the use of sign language (gestural), are on the forefront of communicative breakthroughs in the study of animal language, and they are familiar with their subjects on a first name basis: Sarah, Lana, Kanzi, Koko, Sherman, Austin and Chantek.[ citation needed ]
Perhaps the best known critic of animal language is Herbert Terrace. Terrace's 1979 criticism using his own research with the chimpanzee Nim Chimpsky [44] [45] was scathing and spelled the end of animal language research in that era, most of which emphasized the production of language by animals. In short, he accused researchers of over-interpreting their results, especially as it is rarely parsimonious to ascribe true intentional "language production" when other simpler explanations for the behaviors (gestural hand signs) could be put forth. Additionally, his animals failed to show generalization of the concept of reference between the modalities of comprehension and production; this generalization is one of many fundamental ones that are trivial for human language use. The simpler explanation according to Terrace was that the animals had learned a sophisticated series of context-based behavioral strategies to obtain either primary (food) or social reinforcement, behaviors that could be over-interpreted as language use.
In 1984 Louis Herman published an account of artificial language found in the bottlenose dolphin in the journal Cognition . [46] A major difference between Herman's work and previous research was his emphasis on a method of studying language comprehension only (rather than language comprehension and production by the animal(s)), which enabled rigorous controls and statistical tests, largely because he was limiting his research to evaluating the animals' physical behaviors (in response to sentences) with blinded observers, rather than attempting to interpret possible language utterances or productions. The dolphins' names here were Akeakamai and Phoenix. [46] Irene Pepperberg used the vocal modality for language production and comprehension in a grey parrot named Alex in the verbal mode, [47] [48] [49] [50] and Sue Savage-Rumbaugh continues to study bonobos [51] [52] such as Kanzi and Panbanisha. R. Schusterman duplicated many of the dolphin results in his California sea lions ("Rocky"), and came from a more behaviorist tradition than Herman's cognitive approach. Schusterman's emphasis is on the importance on a learning structure known as equivalence classes. [53] [54]
However, overall, there has not been any meaningful dialog between the linguistics and animal language spheres, despite capturing the public's imagination in the popular press. Furthermore, the growing field of language evolution is another source of future interchange between these disciplines. Most primate researchers tend to show a bias toward a shared pre-linguistic ability between humans and chimpanzees, dating back to a common ancestor, while dolphin and parrot researchers stress the general cognitive principles underlying these abilities. More recent related controversies regarding animal abilities include the closely linked areas of theory of mind, Imitation (e.g. Nehaniv & Dautenhahn, 2002), [55] Animal Culture (e.g. Rendell & Whitehead, 2001), [56] and Language Evolution (e.g. Christiansen & Kirby, 2003). [57]
There has been a recent emergence in animal language research which has contested the idea that animal communication is less sophisticated than human communication. Denise Herzing has done research on dolphins in the Bahamas whereby she created a two-way conversation via a submerged keyboard. [58] The keyboard allows divers to communicate with wild dolphins. By using sounds and symbols on each key the dolphins could either press the key with their nose or mimic the whistling sound emitted in order to ask humans for a specific prop. This ongoing experiment has shown that in non-linguistic creatures sophisticated and rapid thinking does occur despite our previous conceptions of animal communication. Further research done with Kanzi using lexigrams has strengthened the idea that animal communication is much more complex than once thought. [59]
Washoe was a female common chimpanzee who was the first non-human to learn to communicate using signs adapted from American Sign Language (ASL) as part of an animal research experiment on animal language acquisition.
Cetacean intelligence is the overall intelligence and derived cognitive ability of aquatic mammals belonging in the infraorder Cetacea (cetaceans), including baleen whales, porpoises, and dolphins. In 2014, a study found for first time that the long-finned pilot whale has more neocortical neurons than any other mammal, including humans, examined to date.
Yerkish is an artificial language developed for use by non-human primates. It employs a keyboard whose keys contain lexigrams, symbols corresponding to objects or ideas.
Animal cognition encompasses the mental capacities of non-human animals, including insect cognition. The study of animal conditioning and learning used in this field was developed from comparative psychology. It has also been strongly influenced by research in ethology, behavioral ecology, and evolutionary psychology; the alternative name cognitive ethology is sometimes used. Many behaviors associated with the term animal intelligence are also subsumed within animal cognition.
Animal communication is the transfer of information from one or a group of animals to one or more other animals that affects the current or future behavior of the receivers. Information may be sent intentionally, as in a courtship display, or unintentionally, as in the transfer of scent from the predator to prey with kairomones. Information may be transferred to an "audience" of several receivers. Animal communication is a rapidly growing area of study in disciplines including animal behavior, sociology, neurology, and animal cognition. Many aspects of animal behavior, such as symbolic name use, emotional expression, learning, and sexual behavior, are being understood in new ways.
Kanzi, also known by the lexigram , is a male bonobo who has been the subject of several studies on great ape language. According to Sue Savage-Rumbaugh, a primatologist who has studied the bonobo throughout her life, Kanzi has exhibited advanced linguistic aptitude.
Great ape language research historically involved attempts to teach chimpanzees, bonobos, gorillas and orangutans to communicate using imitative human speech, sign language, physical tokens and computerized lexigrams. These studies were controversial, with debate focused on the definition of language, the welfare of test subjects, and the anthropocentric nature of this line of inquiry.
The mirror test—sometimes called the mark test, mirror self-recognition (MSR) test, red spot technique, or rouge test—is a behavioral technique developed in 1970 by American psychologist Gordon Gallup Jr. as an attempt to determine whether an animal possesses the ability of visual self-recognition. The MSR test is the traditional method for attempting to measure physiological and cognitive self-awareness. However, agreement has been reached that animals can be self-aware in ways not measured by the mirror test, such as distinguishing between their own and others' songs and scents, and being aware of their own bodies, while humans have abnormally good vision, and thus intelligence that is highly visual.
The Mind of an Ape is a 1983 book by David Premack and his wife Ann James Premack. The authors argue that it is possible to teach language to (non-human) great apes. They write: "We now know that someone who comprehends speech must know language, even if he or she cannot produce it."
Human–animal communication is the communication observed between humans and other animals, ranging from non-verbal cues and vocalizations to the use of language.
Speech is the use of the human voice as a medium for language. Spoken language combines vowel and consonant sounds to form units of meaning like words, which belong to a language's lexicon. There are many different intentional speech acts, such as informing, declaring, asking, persuading, directing; acts may vary in various aspects like enunciation, intonation, loudness, and tempo to convey meaning. Individuals may also unintentionally communicate aspects of their social position through speech, such as sex, age, place of origin, physiological and mental condition, education, and experiences.
Emily Sue Savage-Rumbaugh is a psychologist and primatologist most known for her work with two bonobos, Kanzi and Panbanisha, investigating their linguistic and cognitive abilities using lexigrams and computer-based keyboards. Originally based at Georgia State University's Language Research Center in Atlanta, Georgia, she worked at the Iowa Primate Learning Sanctuary in Des Moines, Iowa from 2006 until her departure in November 2013.
Animal culture can be defined as the ability of non-human animals to learn and transmit behaviors through processes of social or cultural learning. Culture is increasingly seen as a process, involving the social transmittance of behavior among peers and between generations. It can involve the transmission of novel behaviors or regional variations that are independent of genetic or ecological factors.
Vocal learning is the ability to modify acoustic and syntactic sounds, acquire new sounds via imitation, and produce vocalizations. "Vocalizations" in this case refers only to sounds generated by the vocal organ as opposed to by the lips, teeth, and tongue, which require substantially less motor control. A rare trait, vocal learning is a critical substrate for spoken language and has only been detected in eight animal groups despite the wide array of vocalizing species; these include humans, bats, cetaceans, pinnipeds, elephants, and three distantly related bird groups including songbirds, parrots, and hummingbirds. Vocal learning is distinct from auditory learning, or the ability to form memories of sounds heard, a relatively common trait which is present in all vertebrates tested. For example, dogs can be trained to understand the word "sit" even though the human word is not in its innate auditory repertoire. However, the dog cannot imitate and produce the word "sit" itself as vocal learners can.
A talking animal or speaking animal is any non-human animal that can produce sounds or gestures resembling those of a human language. Several species or groups of animals have developed forms of communication which superficially resemble verbal language, however, these usually are not considered a language because they lack one or more of the defining characteristics, e.g. grammar, syntax, recursion, and displacement. Researchers have been successful in teaching some animals to make gestures similar to sign language, although whether this should be considered a language has been disputed.
Primate cognition is the study of the intellectual and behavioral skills of non-human primates, particularly in the fields of psychology, behavioral biology, primatology, and anthropology.
Laughter in animals other than humans describes animal behavior which resembles human laughter.
Panbanisha, also known by the lexigram , was a female bonobo that featured in studies on great ape language by Professor Sue Savage-Rumbaugh. Her name is Swahili for "to cleave together for the purpose of contrast."
The cooperative pulling paradigm is an experimental design in which two or more animals pull rewards toward themselves via an apparatus that they cannot successfully operate alone. Researchers use cooperative pulling experiments to try to understand how cooperation works and how and when it may have evolved.
Panpanzee the chimpanzee, was born at the Language Research Center at Georgia State University in Atlanta, Georgia. She lived the rest of her life at the Great Ape Trust in Iowa. Her half-brother is Kanzi, a famous bonobo. Kanzi learned 348 lexigram symbols and over 3,000 words from the English language over her lifespan.
We argue that an understanding of the faculty of language requires substantial interdisciplinary cooperation. We suggest how current developments in linguistics can be profitably wedded to work in evolutionary biology, anthropology, psychology, and neuroscience. We submit that a distinction should be made between the faculty of language in the broad sense (FLB) and in the narrow sense (FLN). FLB includes a sensory-motor system, a conceptual-intentional system, and the computational mechanisms for recursion, providing the capacity to generate an infinite range of expressions from a finite set of elements. We hypothesize that FLN only includes recursion and is the only uniquely human component of the faculty of language. We further argue that FLN may have evolved for reasons other than language, hence comparative studies might look for evidence of such computations outside of the domain of communication (for example, number, navigation, and social relations).