Studies of language change frequently wrestle with the problem of cause and correlation. It is comparatively simple to observe a correlation between historical trends. However, it is much more difficult to demonstrate that the changes in the frequency of a construction A were indeed the cause of the changes in the frequency of a construction B. We present a statistical method that can help to assess whether two historical changes are not only correlated, but also causally related. In particular, we use Granger Causality to determine whether the gradual replacement of ex-situ wh-interrogatives with clefted wh-interrogatives in 18th to 20th century Brazilian Portuguese resulted from word order change, and particularly the rise in the frequency of SV word order. Our results indeed suggest that SV word order Granger-causes the use of clefted wh-interrogatives, as well as declarative ‘that’-clefts, but not the other way around.
This introductory paper reviews recent advances in language evolution research and summarizes the contributions of the special issue “New Directions in Language Evolution Research” in the broader context of these developments. Specifically, we discuss the increasing role of multimodality and iconicity, the more integrative view of language dynamics that has arguably broadened the scope of language evolution research, and recent methodological innovations that allow for a more fine-grained study of e.g. typological distributions or behavioral patterns that can give clues to some of the key questions discussed in the field.
The comparative method has enabled us to trace distant phylogenetic relationships among languages and reconstruct extinct languages from the past. Nonetheless, it has limitations, mostly resulting from the circumstance that languages also change by contact with unrelated languages and in response to external factors, particularly, aspects of human cognition and features of our physical and cultural environments. In this paper, it is argued that the limitations of historical linguistics can be partially alleviated by the consideration of the links between language structure and the biological underpinnings of human language, human cognition, and human behaviour, and specifically, of human self-domestication (that is, the existence in humans of features of domesticated mammals). Overall, we can expect that the languages spoken in remote prehistory exhibited most of the features of the so-called esoteric languages, which are used by present-day, close-knit, small human communities that share a great deal of knowledge about their environment.