In July 1954, a British medical journal recorded the extraordinary case of a baby chimpanzee that had been raised like a human child for two years alongside the similarly aged son of an American psychologist.
Gua, reported The Family Doctor, had been "treated not as an animal pet, but as a member of the family - dressed exactly like the child, nursed and trained in the same way, rewarded, scolded or punished in the same way".
At the end of the first year, it was clear that the chimp was out front in the smart stakes; she had learnt to use cups and spoons ahead of her human rival, was walking upright and could recognise 20 commands, including "Open the door" and "Shake hands". The slow-learning chump of a child, meanwhile, was struggling to recognise even three.
What Gua could not do, however, was learn to speak.
By early in the second year, while the chimpanzee was pretty good at acrobatics and scaling stuff, it had become apparent which of the two would be climbing to the top of the food chain. The child "began to use words and phrases quite spontaneously, and to imitate the actions of its elders, in a way that the animal could never manage".
More useful data might be harvested by approaching the question from the opposite direction - would a child raised without human contact lack all speech? Pesky ethics, however, has always prevented such a fascinating experiment, though there are plenty of rural myths about children who have been raised by a varied menagerie of animals. In each case the child, usually discovered before the age of 10, has been reported as being unable to speak, or to learn, human language, while variously growling, hissing or chirping, according to the vocal preference of the adoptive parental species.
At the heart of these myths and a number of ultimately futile experiments with chimpanzees lies the question that has divided the field of linguistics and almost certainly always will do: is language learnt, or is the skill inherent and hard-wired in human beings - and only human beings - as maintained by Noam Chomsky, the pre-eminent linguist, and his legions of devotees?
Within that debate nestles the far more intriguing question of how language happened. Think about it. Did one particular ancient man simply wake up one morning and, instead of announcing his intention to go out hunting and gathering with the usual all-purpose "Ugg", stand up and, to his surprise and that of everyone else's in the cave, say "I'm just popping out to clobber a mammoth for dinner. Anyone fancy joining me?"
Probably not. After all, he would have drawn blank looks all round. Being the first to talk would be a bit like inventing the telephone: what's the point if there's no one to call?
Yet likewise, how could language have evolved as a collaborative, committee-driven Good Idea - and across the globe, more or less simultaneously?
For one thing, how would you get the members of any such committee to the table? Come to that, how would you express the very idea?
Even Chomsky has dodged this question. "It is perfectly safe to attribute this development to 'natural selection'," he once wrote, "so long as we realise that there is no substance to this assertion, that it amounts to nothing more than a belief that there is some naturalistic explanation for these phenomena."
The reality is that, while such speculation is a great deal of fun, the best linguistics brains in the world have never, and can never, come up with a scenario for the birth of language any more or less convincing than the Bible's Tower-of-Babel explanation for how and why our small planet has no fewer than 6,000 different languages confounding our attempts to all get along like one big happy family.