In short, while the gulf between animal and human vocal communication is surely large, scientists are rapidly gaining understanding of the causeway that evolved over that gulf from the animal side. Now let's trace the bridge from the human side. We have already discovered complex animal 'languages'; do any truly primitive human languages still exist?
To help us recognize what a primitive human language might sound like if there were any, let's remind ourselves of the ways in which normal human language differs from vervet vocalizations. One difference is that of grammar. Humans, but not vervets, possess grammar, meaning the variations in word order, prefixes, suffixes, and changes in word roots (such as 'they', 'them', 'their') that modulate the sense of the roots. A second difference is that vervet vocalizations, if they constitute words at all, stand only for things that one can point to or act out. One could try to argue that vervet calls do include the equivalents of nouns ('eagle') and verbs or verb phrases ('watch out for the eagle'). Our words clearly include both nouns and verbs that are distinct from each other, as well as adjectives. Those three parts of a speech referring to specific objects, acts, or qualities are termed lexical items. But up to half of the words in typical human speech are purely grammatical items, with no referent that one can point to.
These grammatical words include our prepositions, conjunctions, articles, and auxiliary verbs (words like 'can', 'may', 'do', and 'should'). It is much harder to understand how grammatical items could evolve than it is for lexical items. Given someone who understands no English, you can point to your nose to explain what that noun means. Apes might similarly come to agree on the meanings of grunts functioning as nouns, verbs, or adjectives. How, though, do you explain the meaning of'by', 'because', 'the', and 'did' to someone who understands no English? How could apes have stumbled on such grammatical terms?
Yet another difference between human and vervet vocalizations is that ours possess a hierarchial structure, such that a modest number of items at each level creates a larger number of items at the next higher level. Our language uses many different syllables, all based on the same set of a few dozen sounds. We assemble those syllables into thousands of words. Those words are not merely strung haphazardly together but are organized into phrases, such as prepositional phrases. Those phrases in turn interlock to form a potentially infinite number of sentences. In contrast, vervet calls cannot be resolved into modular elements and lack even a single stage of hierarchical organization.
As children, we master all of this complex structure of human language without ever learning the explicit rules governing it. We are not forced to formulate the rules unless we study our own language in school or learn a foreign language from books. So complex is our language's structure that many of the underlying rules currently postulated by professional linguists have been proposed only in recent decades. This gulf between human language and animal vocalizations explains why most linguists never discuss how human language might have evolved from animal precursors. They instead regard that question as unanswerable and therefore unworthy even of speculation.
The earliest written languages of 5,000 years ago were as complex as those of today. Human language must have achieved its modern complexity long before that. Can we at least recognize linguistic missing links by searching for primitive peoples with simple languages that might represent early stages of language evolution? After all, some tribes of hunter-gatherers retain stone tools as simple as those that characterized the whole world tens of thousands of years ago. Nineteenth-century travel books abound with tales of backward tribes who supposedly used only a few hundred words or who lacked articulated sounds, were reduced to saying 'ugh', and depended on gestures for their communications. That was Darwin's first impression of the speech of the Indians in Tierra del Fuego. But all such tales proved to be pure myth. Darwin and other western travellers merely found it as hard to distinguish the unfamiliar sounds of non-western languages as non-westerners found English sounds, or as zoologists find the sounds of vervet monkeys. Actually, it turns out that there is no correlation between linguistic and social complexity. Technologically primitive people do not speak primitive languages, as I discovered on my first day among the Fore people in the New Guinea highlands. Fore grammar proved deliciously complex, with postpositions similar to those of the Finnish language, dual as well as singular and plural forms similar to those of Slovenian, and Verb tenses and phrase construction unlike any language I had encountered previously. I have already mentioned the eight vowel tones of New Guinea's lyau people, whose sound distinctions proved impercept-toly subtle to professional linguists for years. Nor could we reverse Darwin's prejudice by claiming an inverse correlation between linguistic and social complexity, citing the advanced civilizations of China and England, whose languages are simple in the sense of having little or no word inflection (verb conjugations and noun declensions). French verbs are much more highly inflected than are modern English verbs (nous aimons, vous aimez, Us aiment, etc.), yet the French consider themselves the most highly civilized people. Thus, while some peoples in the modern world retained primitive tools, none retained primitive languages. Furthermore, Cro-Magnon archaeological sites contain lots of preserved tools but no preserved words. The absence of such linguistic missing links deprives us of what might have been our best evidence about human language origins. We are forced to try more indirect approaches.
One indirect approach is to ask whether some people, deprived of the opportunity to hear any of our fully evolved, modern languages, ever spontaneously invented a primitive language. According to the Greek historian Herodotus, the Egyptian king Psammeticus intentionally carried out such an experiment in the hope of identifying the world's oldest language. The king assigned two newborn infants to a solitary shepherd to rear in strict silence, with instructions to listen for their first words. The shepherd duly reported that both children, after mouthing nothing but meaningless babble until the age of two, ran up to him and began constantly repeating the word becos. Since that word meant 'bread' in the Phrygian language then spoken in central Turkey, Psammeticus supposedly conceded that the Phrygians were the most ancient people. Unfortunately, Herodotus's brief account of Psammeticus's experiment fails to convince sceptics that it was carried out as rigorously as described. It illustrates why some scholars prefer to honour Herodotus as the Father of Lies, rather than as the Father of History. Certainly, solitary infants reared in social isolation, like the famous wolf boy of Aveyron, remain virtually speechless and do not invent or discover a language. However, a variant of the Psammeticus experiment has occurred dozens of times in the modern world. In this variant, whole populations of children heard adults around them speaking a grossly simplified and variable form of language, somewhat similar to that which normal children themselves speak at around the age of two years. The children proceeded unconsciously to evolve their own language, far advanced over vervet communication but simpler than normal human languages. The results were the new languages known as pidgins and Creoles, which may provide us with models of two missing links in the evolution of normal human language. My first experience of a Creole was with the New Guinea lingua franca known either as Neo-Melanesian or pidgin English. (The latter name is a confusing misnomer, since Neo-Melanesian is not a pidgin but rather a creole derived from an advanced pidgin -1 shall explain the difference later—and it is only one of many independently evolved languages equally misnamed as pidgin English.) Papua New Guinea boasts about 700 native languages within an area similar to that of Sweden, but no single one of those languages is spoken by more than three per cent of the population. Not surprisingly, a lingua franca was needed and it arose after the arrival of English-speaking traders and sailors in the early 1800s. Today, Neo-Melanesian serves in Papua New Guinea as the language not only of much conversation, but also of many schools, newspapers, radios, and parliamentary discussions. The advertisement in the appendix to this chapter (see pages 150-51) gives a sense of this newly evolved language.