What Are the Uniquely Human Components of the Language Faculty

9.1 Introduction From a biologist's perspective, language has its own particular design features. It is present in virtually all humans, appears to be mediated by dedicated neural circuitry, exhibits a characteristic pattern of development, and is grounded in a suite of constraints that can be characterized by formal parameters. Th us, language has all the earmarks of an adaptation, suggesting that it could be fruitfully studied from a biological and evolutionary per-On the other hand, linguistic behaviour leaves no fossils, and many characteristics of language appear unique to our species. Th is suggests both that the phylogenetic approach (constructing adaptive narrative that captures the timing and functionality of language evolution in our species) and the comparative approach (using data from other species to gain perspective on characteristics of our own) will be fraught with diffi culty. We tend to agree that the construction of historical narratives of language evolution are too unconstrained by the available data to be profi table at present, especially since many plausible scenarios have already been exhaustively explored (see e.g. Harris 1996). At best, this practice provides a constrained source of new hypotheses to be tested; at worst it degenerates into fanciful storytelling. In contrast, we claim that the comparative approach to language has been and will continue to be a powerful approach to understanding both the evolution and current function of the language faculty. Our purpose in this chapter is to review the current state of the art in comparative studies of the faculty of language, focusing specifi cally on the sensory motor system involved in the production and perception of acoustic