Linguistics Language and Literacy

Our current estimate of when language itself evolved is based on skeletal evidence for a swift evolutionary push toward the modern human vocal tract during the Upper Paleolithic. These changes—away from the throat, tongue, and mouth configuration typical of other primates—made rapid spoken speech possible while making it easier to die of obstructed air passages (choking, etc.). Such difficulties for the individual must have been well offset for the species by the survival benefits of rapid, voluntary, and abstract communication, one of humankind's most powerful "ideas." Indeed, language's most important design characteristics are that it is:

1. voluntary (unlike the call systems of other primates, speech is initiated from the voluntary part of the motor cortex);
2. arbitrary (we can talk even about things that do not exist, allowing us to solve hypothetical problems and form abstractions; language is not tied to immediate reality);
3. productive (we can use already known vocabulary and syntactic patterns to generate an infinite supply of new messages, not to mention new vocabulary and patterns);
4. largely linear (messages unfold rapidly through time, a choice that places major constraints on the details of language design); and
5. two-way (individuals can both produce and understand messages).

As a result of being arbitrary, languages must be learned. Only the propensity to learn language is instinctive, not the individual languages themselves. Hence, babies must have a long period of apprenticeship to learn to communicate linguistically, a fact equally true of spoken tongues and visual languages like American Sign Language (ASL). (ASL has all the structural features and design complexities of a spoken language, only in a different—and equally evanescent—medium.) Research shows that children deprived of early exposure to linguistic communication (which happens sometimes with deaf babies) do not develop the neurological structures in the brain necessary for handling the complexities of language later.

Because languages are arbitrary, they change constantly, adapting easily to the changing world of things to talk about and social messages to send. As a result of this constant change, speakers of a single language who move away from each other will change their systems differently, a process that may continue until we perceive them as speaking different dialects or even (after many centuries) different languages. This process is called language divergence and leads to what linguists call language families.

The members of a language family are simply changed later forms of what was once one language. For example, the speakers of Latin fanned out across the Roman Empire 2,000 years ago, but after the breakup of the empire, when travel became dangerously difficult, the local versions of Latin began to diverge, producing the so-called Romance language family, consisting notably of Italian, French, Spanish, Portuguese, and Romanian (along with several other dialects and languages, less well known because they have fewer speakers). But Latin itself was a changed later form of yet older languages, going back to something we call proto-Italic (for lack of knowing what its speakers called it), and even further back to one we call proto-Indo-European.