Language (zoology)

One way to understand humans’ position in the natural order of evolution is to locate the origins of language. Some scholars think that language is probably the product of the “mental mutation” of the large brain of Homo sapiens because human language is the only animal communicative system that possesses all the fundamental characteristics of arbitrary symbols, semanticity, grammar, productivity, the duality of patterning, and displacement. Furthermore, human children can become effective users of such complex symbolic systems without formal teaching and within a fairly short period, in striking contrast to the limited expressions of animals, even after lengthy and extensive training. Linguist Noam Chomsky, for example, proposed that human beings have a unique language-forming capacity and human babies are innately equipped with a “Language Acquisition Device,” which resides somewhere in the brain.

Many others, however, disagree with this discontinuity theory of the origin of human language. Instead, they argue for an evolutionary ground—neuroanatomical, behavioral, cognitive, social, and cultural—to cultivate language formation. They believe that language is no exception from the governing of the law of evolution. For example, Philip Lieberman rejected the existence of linguistic genes or a language organ in the human brain. Rather, language had its first sprout at the intersection of the evolutionary products of neural mechanisms, communication, and cognition. These are the two main theories of language origins. The first line builds on the protolanguage theory, and the second on the notion of behavior determinism in evolution.

Protolanguage Theory

“Protolanguage” means that utterances are not yet full language, although they serve symbolic referential and other communicative functions. The telegraphic speech of toddlers (such as “Mommy cookie!”) has been used as an example. A “baby talk” was formed first, only to be shaped and refined later into a full language. It was hypothesized that modern speech could have been possible about 100,000 years ago when the earliest Homo sapiens migrated from Africa to other places. John McCrone reasoned that toolmaking and tool use, moving troops to other regions, and collective hunting called for more group actions, which, in turn, promoted social interaction. These activities required joint attention and intentional communication. Using eye contact and gestures to direct attention as a means beyond reflexive behaviors to achieve joint attention might, thus, have been a major step toward human speech. The prolonged period for taking care of dependent human infants, a consequence of brain growth, afforded opportunities to cultivate the intimacy between mother and child. Meanwhile, social ties in a colony began to form. These changes might have encouraged what could be called personalized noises. To meet their communicative needs, early Homo species were pressured to refine and stabilize their coarse communicative noises into protowords. These protowords were passed down through generations. The practice of such vocalizations further promoted vocal structure refinement.

The evolutionary principle of economy and efficiency was at work so that concept categories (words) and combinatorial rules (grammar) were naturally selected. Words and grammar are far more cognitively economic and efficiently generative than mechanical one-to-one referential associations. Martin Nowak and David Krakauer, based on their mathematical and computational modeling using computer simulations, contended that protolanguages can evolve in a nonlinguistic society. At first, signal-object associations were established, and later, combinations of sounds to form words and combinations of words to form sentences evolved into semantic and syntactic systems through natural selection to reduce mistakes in communication.

In addition to the supportive results of computer simulations, other empirical evidence came from studies involving primates and human children. In Leavens and Hopkins’s study, 115 chimpanzees (Pan troglodytes) in captivity (aged three to fifty-six years), without any explicit training whatsoever, commonly employed gaze alterations and a pointing gesture in face-to-face communicative interactions with humans and among themselves. This demonstrated the presence of communicative intent and gestural precursors of language among humans’ closest relatives, chimpanzees. The bonobo (Pan paniscus), Kanzi, understood spoken English sentences and knew how to use human-designated lexigrams to announce his intention, all through laissez-faire learning without explicit teaching. The chimpanzee Washoe spontaneously taught her acquired American Sign Language (ASL) to her adopted son Loulis. Human babies are like chimpanzees in many ways. As McCrone described it, human infants are born with the standard ape vocal plan—after six months, the voice box descends into the throat. Human infants first play with vowels (coo) and then babble (combining vowels with consonants)—so vocalization comes before producing true words. They also employ gaze alterations and gestures to communicate before they say words. In the second year, they produce telegraphic speech, typically composed of two to three content words, which happens to be the mode of expression in the utterances of language-trained chimps (such as “Shirt hide” by Kanzi).

Behavior Determinism

William Noble and Iain Davidson do not think that a protolanguage existed in evolution. They have also cautioned people against accepting the performance of animals in captivity and human interaction experiences as evidence to back up evolutionary arguments because these environments are drastically different from the ecologies of the Homo ancestors millions of years ago. These environments are not the same as those of the free-living primates, either. Language-trained animals’ performance is like language emergence in human infants, who learn through interaction with other humans who already have language, a learning process quite different from the prehistoric origins of symbols and language from scratch.

Noble and Davidson agree that natural selection favored bipedalism, leading to neuroanatomical changes, including larger brains. They do not believe, however, in the biological determination of behaviors. Instead, they believe the opposite. The behavior of standing upright led to larger brains that needed to consume more energy. Meat as a good energy source had already been increased in the diet of Homo erectus. As meat-eaters, hominids had to run fast (either to catch prey or to escape predators). Running brought about better control of the breathing system (necessary for speaking) and adjustments to the thermoregulatory system (leading to the selection of the feature “hairlessness,” which could have fostered face-to-face adult-infant interaction). Additionally, hunting for meat facilitated coordinated group actions and tool creation. To expand food sources, hominids began migrating, which further promoted groups and interaction. Thus, the social context was present for the emergence of language.

In their discussion, Noble and Davidson emphasized one important behavior responsible for the emergence of language—stone throwing. To be effective, manual control and timing control had to be achieved. As the timing control behaviors were bettered, the neuroanatomical structures improved, too. These positive adjustments, together with other contextual changes, led hominids on an increasingly divergent behavioral path from their chimpanzee relatives. Better control of the forearm could develop into a pointing form. Hairlessness made it easy to carry an infant hominid in front, increasing the likelihood of adult-baby mutual observation and imitation. One such behavior could be arm extensions for referring. Later, better-controlled movements of forearms and fingers developed into a pointing form. Any vocalizations in company with manual gestures were first associated with the referred objects and later became symbols once it was realized that the sounds alone could stand for the targets themselves, even when they were out of sight.

There is consensus that the human vocal structure is a necessary condition for human speech. It has been noticed that animal vocalizations are graded in nature. A graded system contains only variations of vowel sounds but no consonants. Variations of vowels, although functional in communication, lack distinctive boundaries to mark different categories. Sue Savage-Rumbaugh and Roger Lewin have concluded that language is unlikely to emerge unless an organism can produce consonants, no matter how large its brain. How the human vocal tract acquired the ability to pronounce consonants remains a mystery.

The evolution of language must have benefited the Homo species tremendously. Noble and Davidson speculated how language could have contributed to human mentality. For example, colonization in different places would cause isolated groups to have trouble understanding each other. Such failures and misunderstandings could contribute to the awareness of “us” vs. “them.” This appreciation would lead to the realization of the possibility for a group to use their own symbolic system as a means of social control. Thus, human mentality, with language in use, is itself an evolving feature of the natural world. It is only logical that, with language available, mental representation of the world became possible, which eventually made abstract, imaginary, retrospective, hypothetical, and metacognitive thinking a reality. No wonder these modes of thinking reflect themselves in the characteristics of human language.

Animal Communication

Animals do communicate, at least in a broad sense. Animals use vocalizations, facial expressions, gestures, body postures and movements, and even odors, to warn peers, to attract attention, to find food, to care for the young, to mark territories, and to maintain social structures. However, animal communicative systems are typically not recognized as language because they lack the key features of a true language. Many have argued that animal communication, even among chimpanzees, is, in essence, instinctive and reflexive. McCrone says that these behaviors are not under conscious control and are triggered only by an event in the immediate environment, with both parties present. Hence, chimpanzees have no true arbitrary symbols or displacement. Additionally, animal communicative systems are “closed,” with no combinatorial rules to create new meanings; hence, they lack duality of patterning, syntax, and productivity. Edward Kako pointed out that no animals, including language-trained animals, have demonstrated the ability to understand closed-class lexical items. Despite the criticisms, animals’ language-learning achievements have been acknowledged.

Talking Animals

One of the most famous talking parrots is Alex (1976–2007), an African grey parrot (Psittacuserithacus) trained by animal psychologist Irene Pepperberg. Alex spoke many words and phrases referring to objects, materials, actions, colors, shapes, numbers, and locations. He answered questions that required labeling objects, classifying objects (color and substance), comparing objects (“bigger than” or “same as/different from”), and counting (from one to six). Another African grey parrot, Apollo, hatched in 2020, is the star of the YouTube channel "Apollo and Frens" where he shows off vocabulary and item identification skills. In 2023, he earned the Guinness World Record title for the most items identified by a parrot in three minutes. He can accurately identify and vocalize if a given item is made of wood, glass, plastic, paper, or metal. He also has simple conversations with his owners, asks questions, and exhibits exceptional emotional intelligence.

In the 1970s, American marine biologist Louis Herman and his colleagues trained two Hawaii bottle-nosed dolphins (Tursiops truncatus) named Phoenix, with an acoustic language, and Akekamai (Ake), with a gesture-based language. They could correctly carry out commands in varied word orders (syntax) with different meanings. They further demonstrated their semantic and grammatical knowledge by either not executing grammatically incorrect and semantically nonexecutable orders or by extracting an executable segment from an anomalous string and then completing the task according to the meaning provided in that specific syntactic structure.

In the 1990s, primatologist Sue Savage-Rumbaugh's bonobo, Kanzi (b. 1980), became an exciting language star. Kanzi understands spoken English and uses hand signals as well as geometric symbols. Moreover, he learned all that without explicit instruction but by mere social observation and interaction, just as a human baby learns a language. This natural learning process was successfully replicated with Kanzi’s sister, Panbanisha (1985–2012). Kanzi was featured in a 2023 video playing a modified version of the video game Minecrafta fundraising event for The Ape Initiative.

Comparative Language Research

Research methodology in the comparative language field has been improved greatly in the twenty-first century. Designation of language considers the biological constraints of the species involved. Social interaction, in a natural way, is underscored. Possible experimenters’ and trainers’ biases are controlled through blind techniques, such as blindfolding the eyes of the person who gives commands, using one-way mirrors and remote cameras, or separating the person who does the recording and interpretation from the one who gives the command. Some scientists use the playback technique to decode the meaning of the signals in animals’ own communicative systems. Many species have been studied in their natural ecological niches, including vervet monkeys, tigers, humpback whales, orcas or killer whales, and elephants. These animals’ wild calls are recorded in nature and played back to the animals to see their differentiated reactions, making message decoding possible. The playback studies are very encouraging in confirming the symbolic nature of animals’ natural “languages” in the wild. Beginning in the early 2020s, scientists made breakthroughs in the understanding of animal language using artificial intelligence (AI) to analyze patterns and chatter. One organization, Earth Species Project (ESP), particularly aimed to decode animals' language, with the goal of eventually reaching two-way communication between humans and animals. The non-profit's dedication to improving AI to enhance human-to-non-human communication has been instrumental in technological development.

It is very important to study the animal’s own “language” for its own sake. Without such knowledge, commenting on nonhuman species’ linguistic abilities in the frame of human language is at least prejudiced. As primatologist and psychologist Roger Foutes noted, “The best approach to science is a humble one. We are humble enough to take the animals we are studying on their own terms and allow them to tell us about themselves. Too often, science takes an arrogant approach.” According to him, “Someday we’ll realize that the human voice is not a lone violin but part of an orchestra. We’re not playing a solo; instead it’s a symphony.”

Principal Terms

Closed-Class Vocabulary: Typically including the structural and functional words, such as prepositions, determiners, quantifiers, and morphological markers, closed in the sense of resisting the introduction of new members

Displacement: Language’s power to refer to or describe things and events beyond the constraints of the here and now

Grammar: The structure of a language, consisting of systematic rules to specify word formation, such as inflection, derivation, and compound words (morphology), and systematic rules to specify how words should be ordered in combination to form phrases and sentences (syntax)

Open-Class Vocabulary: Content words, such as nouns, verbs, and adjectives, open in the sense of its readiness to admit new members

Productivity or Generativity: Language’s power to produce or generate an infinite number of understandable words and sentences from a finite number of symbols and rules

Semanticity: Meaning in language

Symbol: Something that stands for something else, the connection between symbol and object being arbitrary in nature

Bibliography

"Are Humans the Only Animals That Use Language?" Cricket Learning, 30 Apr. 2024, blog.cricketelearning.com/are-humans-the-only-animals-that-use-language. Accessed 10 Sept. 2024.

Chomsky, Noam. Aspects of the Theory of Syntax. 50th Anniversary ed. Cambridge, MIT Press, 2015.

Gardner, R. Allen, Beatrix T. Gardner, and Thomas E. Van Cantfort, eds. Teaching Sign Language to Chimpanzees. New York City, State University of New York Press, 1989.

Kako, Edward. “Elements of Syntax in the Systems of Three Language-Trained Animals.” Animal Learning and Behavior, vol. 27, no. 1, 1999, pp. 1-14. doi:10.3758/BF03199424.

Leavens, David A., and William D. Hopkins. “Intentional Communication by Chimpanzees: A Cross-Sectional Study of the Use of Referential Gestures.” Developmental Psychology, vol. 34, no. 3, 1998, pp. 813-822. doi.org/10.1037/0012-1649.34.5.813.

Lieberman, Philip. The Biology and Evolution of Language. Boston, Harvard University Press, 1984.

Newcomb, Tim. "Humans May Be Shockingly Close to Decoding the Language of Animals." Popular Mechanics, 27 Jan. 2023, www.popularmechanics.com/science/animals/a42689511/humans-could-decode-animal-language. Accessed 10 July 2023.

Noble, William, and Iain Davidson. Human Evolution, Language, and Mind: A Psychological and Archaeological Inquiry. Cambridge,, Cambridge University Press, 2009.

Nowak, Martin A., and David C. Krakauer. “The Evolution of Language.” Proceedings of the National Academy of Sciences of the United States, vol. 96, no. 14, July 1999, pp. 8028-8033. doi.org/10.1073/pnas.96.14.8028.

Patterson, Francine, and Eugene Liden. The Education of Koko. Holt, Rinehart and Winston, 1981.

Premack, David. “Language in Chimpanzee?” Science, vol. 172, 1971, pp. 808-822. doi:10.1126/science.172.3985.808.

Rumbaugh, Duane M., and E. Sue Savage-Rumbaugh. “Language in Comparative Perspective.” In Animal Learning and Cognition, edited by N. J. London, Mackintosh. Academic Press, 1994.

Savage-Rumbaugh, Sue, and Roger Lewin. Kanzi: The Ape at the Brink of the Human Mind. Hoboken, John Wiley & Sons, 1994.

Savage-Rumbaugh, Sue, et al. “The Fully Conscious Ape.” International Journal of Comparative Psychology, 2018, escholarship.org/uc/item/8ff0q2mq.

Taylor, Martha R., et al. Campbell Biology: Concepts & Connections. 10th ed., New York City, Pearson Education Limited, 2022.