Language steamrollers?

Abstract

Diamond replies — By ‘language steamroller’ is meant the massive replacement of a region's languages by languages from the outside. Some military, technological, political or demographic advantage enables outsiders to impose their language or even to conquer or replace the original inhabitants. Terrell et al. question whether the suggested ‘steamrollers’ could be real, whereas Sterrer discusses their interpretation.

Main

The evidence for steamrollers is overwhelming and familiar. In modern times, European overseas expansion resulted in English, Spanish, French and Portuguese replacing thousands of native languages of other continents. (Why else would this issue of Nature be printed for North American readers in English, rather than in a Native American language?) Abundant linguistic evidence testifies to many equally massive earlier replacements, of which the Bantu expansion over sub-Saharan Africa and the Austronesian expansion over the tropical Pacific are particularly well attested by independent archaeological and genetic evidence.

In western Europe, all of the many modern languages except Basque belong to the Indo-European language family, which diversified during the past 5,000-10,000 years from an ancestral language spoken somewhere in western Asia. Do Terrell et al. believe all Europeans spoke a single tongue, Basque, until a few thousand years ago? In fact, preserved Etruscan and Iberian writing from Roman times, and residues of non-Indo-European words swept up into existing European languages, testify to the existence of many other non-Indo-European languages supplanted by Indo-European. Whether former language diversity in Europe was higher or lower than in modern New Guinea and aboriginal California is beside the point; the supplanting of that diversity still cries out for explanation.

As for the mechanism of that supplanting, Sterrer is correct: there are various types of advantage that can enable one group of people to conquer (or to impose their language on) another. Most known steamrollers can ultimately be related in some way to food production, because it is the agent that has produced the biggest effects on human population numbers and human societies in the past 10,000 years.

There is a long-standing and unresolved debate over whether the Indo-European steamroller was driven by the demographic advantages that West Asian food producers gained 9,000 years ago over Europe's original hunter/gatherer population, or whether the domestication of the horse (the jeep and Sherman tank of ancient warfare) became crucial after 6,000 years ago. As Sterrer notes, Gimbutas¹³ amassed strong arguments for the latter view, but Renfrew¹⁴ has also made a strong case for the former view. This is just one example of the many fascinating problems posed by the language steamrollers that jump out at us from language maps of the world.