Origin of language


The origin of language, its relationship with human evolution, and its consequences have been subjects of study for centuries. Scholars wishing to study the origins of language draw inferences from evidence such as the fossil record, archaeological evidence, and contemporary language diversity. They may also study language acquisition as well as comparisons between human language and systems of animal communication. Many argue for the close relation between the origins of language and the origins of modern human behavior, but there is little agreement about the facts and implications of this connection.
The shortage of direct, empirical evidence has caused many scholars to regard the entire topic as unsuitable for serious study; in 1866, the Linguistic Society of Paris banned any existing or future debates on the subject, a prohibition which remained influential across much of the Western world until the late twentieth century. Various hypotheses have been developed on the emergence of language. While Charles Darwin's theory of evolution by natural selection had provoked a surge of speculation on the origin of language over a century and a half ago, the speculations had not resulted in a scientific consensus by 1996. Despite this, academic interest had returned to the topic by the early 1990s. Linguists, archaeologists, psychologists, and anthropologists have renewed the investigation into the origin of language with modern methods.

Approaches

Attempts to explain the origin of language take a variety of forms:
  • "Continuity theories" build on the idea that language exhibits so much complexity that one cannot imagine it simply appearing from nothing in its final form; therefore it must have evolved from earlier pre-linguistic systems among humans' primate ancestors.
  • "Discontinuity theories" take the opposite approach, stating that language, as a unique trait that cannot be compared to anything found among non-humans, must have appeared fairly suddenly during the course of human evolution.
  • Some theories consider language mostly as an innate faculty—largely genetically encoded.
  • Other theories regard language as a mainly cultural system that is learned through social interaction.
Most linguistic scholars favor continuity-based theories, but they vary in how they hypothesize language development. Some among those who consider language as mostly innate avoid speculating about specific precursors in non-human primates, stressing simply that the language faculty must have evolved gradually.
Those who consider language as learned socially, such as Michael Tomasello, consider it developing from the cognitively controlled aspects of primate communication, mostly gestural rather than vocal. Where vocal precursors are concerned, many continuity theorists envisage language as evolving from early human capacities for song.
Noam Chomsky, a proponent of discontinuity theory, argues that a single change occurred in humans before leaving Africa, coincident with the Great Leap approximately 100,000 years ago, in which a common language faculty developed in a group of humans and their descendants. Chomsky bases his argument on the observation that any human baby of any culture can be raised in a different culture and will completely assimilate the language and behaviour of the new culture in which they were raised. This implies that no major change to the human language faculty has occurred since they left Africa.
Transcending the continuity-versus-discontinuity divide, some scholars view the emergence of language as the consequence of some kind of social transformation that, by generating unprecedented levels of public trust, liberated a genetic potential for linguistic creativity that had previously lain dormant. "Ritual/speech coevolution theory" exemplifies this approach. Scholars in this intellectual camp point to the fact that even chimpanzees and bonobos have latent symbolic capacities that they rarely—if ever—use in the wild. Objecting to the sudden mutation idea, these authors argue that even if a chance mutation were to install a language organ in an evolving bipedal primate, it would be adaptively useless under all known primate social conditions. A very specific social structure – one capable of upholding unusually high levels of public accountability and trust – must have evolved before or concurrently with language to make reliance on "cheap signals" an evolutionarily stable strategy.
Since the emergence of language lies so far back in human prehistory, the relevant developments have left no direct historical traces, and comparable processes cannot be observed today. Despite this, the emergence of new sign languages in modern times—Nicaraguan Sign Language, for example—may offer insights into the developmental stages and creative processes necessarily involved. Another approach inspects early human fossils, looking for traces of physical adaptation to language use. In some cases, when the DNA of extinct humans can be recovered, the presence or absence of genes considered to be language-relevant—FOXP2, for example—may prove informative. Another approach, this time archaeological, involves invoking symbolic behavior that may leave an archaeological trace—such as mining and modifying ochre pigments for body-painting—while developing theoretical arguments to justify inferences from symbolism in general to language in particular.
The time range for the evolution of language or its anatomical prerequisites extends, at least in principle, from the phylogenetic divergence of Homo from Pan to the emergence of full behavioral modernity some 50,000–150,000 years ago. Few dispute that Australopithecus probably lacked vocal communication significantly more sophisticated than that of great apes in general, but scholarly opinions vary as to the developments since the appearance of Homo some 2.5 million years ago. Some scholars assume the development of primitive language-like systems as early as Homo habilis, while others place the development of symbolic communication only with Homo erectus or with Homo heidelbergensis and the development of language proper with Homo sapiens, currently estimated at less than 200,000 years ago.
Using statistical methods to estimate the time required to achieve the current spread and diversity in modern languages, Johanna Nichols—a linguist at the University of California, Berkeley—argued in 1998 that vocal languages must have begun diversifying in the human species at least 100,000 years ago. Estimates of this kind are not universally accepted, but jointly considering genetic, archaeological, palaeontological, and much other evidence indicates that language likely emerged somewhere in sub-Saharan Africa during the Middle Stone Age, roughly contemporaneous with the speciation of Homo sapiens.

Language origin hypotheses

Early speculations

In 1861, historical linguist Max Müller published a list of speculative theories concerning the origins of spoken language:
  • Bow-wow. The bow-wow, or cuckoo, theory, which Müller attributed to the German philosopher Johann Gottfried Herder, saw early words as imitations of the cries of beasts and birds.
  • Pooh-pooh. The pooh-pooh theory saw the first words as emotional interjections and exclamations triggered by pain, pleasure, surprise, etc.
  • Ding-dong. Müller suggested what he called the ding-dong theory, which states that all things have a vibrating natural resonance, echoed somehow by humans in their earliest words.
  • Yo-he-ho. The yo-he-ho theory claims that language emerged from collective rhythmic labor; that is, the attempt to synchronize muscular efforts resulting in sounds such as heave alternating with sounds such as ho.
  • Ta-ta. The ta-ta theory did not feature in Max Müller's list, having been proposed in 1930 by Sir Richard Paget. According to the ta-ta theory, humans made the earliest words by tongue movements that mimicked manual gestures, rendering them audible.
Most scholars today consider all such theories not so much wrong—they occasionally offer peripheral insights—as naïve and irrelevant. The problem with these theories is that they rest on the assumption that once early humans had discovered a workable mechanism for linking sounds with meanings, language would automatically have evolved.
Much earlier, medieval Muslim scholars developed theories on the origin of language. Their theories were of five general types:
  1. Naturalist: There is a natural relationship between expressions and the things they signify. Language thus emerged from a natural human inclination to imitate the sounds of nature.
  2. Conventionalist: Language is a social convention. The names of things are arbitrary inventions of humans.
  3. Revelationist: Language was gifted to humans by God, and it was thus God—and not humans—who named everything.
  4. Revelationist-Conventionalist: God revealed to humans a core base of language—enabling humans to communicate with each other—and then humans invented the rest of language.
  5. Non-Committal: The view that conventionalist and revelationist theories are equally plausible.

    Problems of reliability and deception

From the perspective of signalling theory, the main obstacle to the evolution of language-like communication in nature is not a mechanistic one. Rather, it is the fact that symbols—arbitrary associations of sounds or other perceptible forms with corresponding meanings—are unreliable and may as well be false. The problem of reliability was not recognized at all by Darwin, Müller or the other early evolutionary theorists.
Animal vocal signals are, for the most part, intrinsically reliable. When a cat purrs, the signal constitutes direct evidence of the animal's contented state. The signal is trusted, not because the cat is inclined to be honest, but because it just cannot fake that sound. Primate vocal calls may be slightly more manipulable, but they remain reliable for the same reason—because they are hard to fake. Primate social intelligence is "Machiavellian"; that is, self-serving and unconstrained by moral scruples. Monkeys, apes and particularly humans often attempt to deceive each other, while at the same time remaining constantly on guard against falling victim to deception themselves. Paradoxically, it is theorized that primates' resistance to deception is what blocks the evolution of their signalling systems along language-like lines. Language is ruled out because the best way to guard against being deceived is to ignore all signals except those that are instantly verifiable. Words automatically fail this test.
Words are easy to fake. Should they turn out to be lies, listeners will adapt by ignoring them in favor of hard-to-fake indices or cues. For language to work, listeners must be confident that those with whom they are on speaking terms are generally likely to be honest. A peculiar feature of language is displaced reference, which means reference to topics outside the currently perceptible situation. This property prevents utterances from being corroborated in the immediate "here" and "now". For this reason, language presupposes relatively high levels of mutual trust in order to become established over time as an evolutionarily stable strategy. This stability is born of a longstanding mutual trust and is what grants language its authority. A theory of the origins of language must therefore explain why humans could begin trusting cheap signals in ways that other animals apparently cannot.