The Evolution of Linguistic Diversity

Coordination: Amina Mettouchi (EPHE – PSL)

There is increasing recognition that the incredible diversity of the world’s 7,000 languages should not be regarded as superficial variations on a fictitious or empirically vague ‘universal grammar’. Rather, it should be looked straight in the face: the  deep variability across the world’s languages mirrors the variability of species found in the biological realm. Just as it was Darwin’s search for evolutionary processes able to encounter for nature’s incredible variety which laid the foundations for modern biology, so linguistics will only become a mature science when we develop explanatory accounts of how the full range of linguistic diversity has evolved. Expressed another way, all sciences seek general laws, including linguistics. But where for generative approaches the general laws were taken to be those generating different surface structures from a generalised set of deep structures, in coevolutionary approaches the general laws pertain to the processes that engender language structures, not the structures themselves. This fundamental shift, which moves diversity from noise to signal in the study of the world’s languages (Evans & Levinson 2009, Evans 2013), is the theme of this course.

In these four lectures we examine how linguistic diversity arises. We take a coevolutionary approach that goes beyond interplays between language-internal factors and brings in a broad range of selectors – cultural, demographic, population-genetic, climatic, economic, system-internal – that nudge the evolution of linguistic systems to different points in the ‘design space’ over hundreds of iterated generations of language change. Drawing on the extraordinary facts of linguistic diversity from around the world, we will develop a general account of how such diverse linguistic systems can arise from the crucible of their particular cultural and environmental conditions. The broader goal is to establish a long-term dialogue between linguists and philologists interested in the particularities of the languages they study in particular cultural and historical contexts, and a general theory of how the world’s exuberant linguistic diversity has come into existence, just as in biology the extraordinary variety of life-forms has driven the development of a sophisticated and multi-level theory of evolution.