The undesirability of a society communicating only in an unwritten language is its ephemerality if the language is immaterial (voice, sound, gesture) or its abstractness if it is material (a circle of stones, a knotted string, symbolic colours). In dwindling primitive tribes, the cultural legacies will be lost when members of the tribes no longer understand the unwritten languages. In some countries, the use of a non-latin script for writing is, for the purposes of using modern telecommunications, the same as if the language were unwritten, since the letters or characters cannot be transmitted or entered into computers.
The majority of the 3,500 languages and dialects in the world, some 3,000 in fact, are unwritten. Mexican Indians have over 100 unwritten languages and dialects for example, and India has over 1,000. A study by the Massachusetts Institute of Technology estimates that 3,000 of the worlds 6,000 languages are doomed because no children speak them. Africa alone has 1,800 languages, Indonesia 672, and New Guinea 800. Only 300 are estimated to have a secure future.
A UNEP report in 1999 indicated that of the estimated 5,000 to 7,000 languages spoken around the world, nearly 2,500 are in danger of immediate extinction. An even higher number are losing the ecological contexts that keep them as vibrant languages. UNESCO estimated that 4,000 to 5,000 of these languages are spoken by indigenous peoples.