The Early History Of Indo-European Languages

Thomas V. Gamkrelidze and V. V. Ivanov
Scientific American, March 1990, pp. 110-116*

Linguistics, the scientific study of  language, can reach more deeply into the human past than the most ancient written records. It compares related languages to reconstruct their immediate progenitors and eventually their ultimate ancestor, or protolanguage. The protolanguage in turn illuminates the lives of its speakers and locates them in time and place.

The science developed from the study of the Indo-European superfamily of languages, by far the largest in number of languages and number of speakers. Nearly half of the world’s population speaks an Indo-European language as a first language; six of the 10 languages in which Scientific American appears–English, French, German, Italian, Russian and Spanish–belong to this superfamily.

Early studies of Indo-European languages focused on those most familiar to the original European researchers: the Italic, Celtic, Germanic, Baltic and Slavic families. Affinities between these and the “Aryan” languages spoken in faraway India were noticed by European travelers as early as the 16th century. That they might all share a common ancestor was first proposed in 1786 by Sir William Jones, an English jurist and student of Eastern cultures. He thus launched what came to be known as the Indo-European hypothesis, which served as the principal stimulus to the founders of historical linguistics in the 19th century.

In their reconstruction of the ancestral Indo-European language, the early linguists relied heavily on Grimm’s law of Lautverschiebung (“sound shift”), which postulated that sets of consonants displace one another over time in predictable and regular fashion. The law was posed in 1822 by Jacob Grimm, who is more widely famed for the anthology of fairy tales he wrote with his brother, Wilhelm. Grimm’s law explained, among other things, why in the Germanic languages certain hard consonants had persisted despite their universal tendency to yield to soft ones. The set of softer, “voiced” consonants “b,” “d,” “g” (followed by momentary vibration of the vocal cords), posited in the protolanguage, had apparently given way to the corresponding hard set “p,” “t,” “k.” According to Grimm’s law, this had come about by “devoicing” those consonants (“p,” for example, is unaccompanied by vocal vibration). Thus, the Sanskrit dhar is seen as an archaic form of the English “draw,” which is itself more archaic than the German tragen (all of which mean “to pull”).

More recent evidence now places the probable origin of the Indo-European language in western Asia. Three generations of archaeologists and linguists have thus far excavated and deciphered manuscripts in close to a dozen ancient languages from sites in modern Turkey and as far east as Tocharia, in modern Turkestan. Their observations, together with new ideas in pure linguistic theory, have made it necessary to revise the canons of linguistic evolutions.

The landscape described by the protolanguage as now resolved must lie somewhere in the crescent that curves around the southern shores of the Black Sea, south from the Balkan peninsula, east across ancient Anatolia (today the non-European territories of Turkey) and north to the Caucasus Mountains. Here the agricultural revolution created the food surplus that impelled the Indo-Europeans to found villages and city-states from which, about 6,000 years ago, they began their migrations over the Eurasian continent and into history. (See Also: Evolution and Locale Maps)

The diverging pathways of linguistic transformation and human migration may now be traced back to a convergence in the Indo-European protolanguage and its homeland. This has followed from the revision in the canons of phonology we mentioned above. An uncontested peculiarity of the sound system of the protolanguage, for example, is the near absence, or suppression, of one of the three consonants “p,” “b” or “v,” which are labials (consonants sounded with the lips). Traditionally, it had been thought that “b” was the suppressed consonant. Subsequent studies in phonology indicated, however, that if one of the three labial consonants is lacking in a language, it is least likely to be the one sounded as “b” in English and other living European languages.

According to classical theory, the “stop” consonants–those that are sounded by interruption of the outward flow of the breath that excites the vibration of the glottis, or vocal cords–are divided into three categories. The labial stop consonant “b” appears in the first column as a voiced consonant; the parentheses enclosing it there indicate its supposed suppression. It is associated with two other voiced stop consonants: “d” (stopped by the forward part of the tongue against the palate) and “g” (stopped by the back of the tongue against the palate).

In the scheme we have developed the corresponding consonants are sounded with a glottalized stop: a closure of the throat at the vocal cords that prevents the outward flow of breath. Here the voiceless labial stop (“p'”) appears suppressed, followed by “t'” and “k'”. As (“p'”) is to (“b”), voiceless and voiced, respectively, so “t'” is to “d” and “k'” is to “g”. Glottalized stops occur in many different language families, particularly those of northern Caucasian and southern Caucasian (Kartvelian) provenance. The glottalized stop–which hardens a consonant–tends to weaken and disappear in most languages of the world. So we surmised that–among the labial stops–it was the “p'” rather than the “b” that most likely had been suppressed in the Indo-European protolanguage.