Sign Iconicity and its Contribution to Gesture-First Theories of Language Origin

How language began is one of the oldest questions in science. This chapter reviews the evidence for the vocal-first, gesture-first and multimodal theories of language origin. First, it considers the nature of signs, and argues that signs exist on a continuum that ranges from iconic to symbolic. Next, a general theoretical model of language creation is outlined, and the naturalistic and experimental evidence for each theory is reviewed. While there is naturalistic evidence to support each theory, the experimental evidence supports the gesture-first theory of language origin. The experimental work indicates the advantage of gesture lies in its affordance for the production of iconic signs, which are crucial to communication success. The chapter closes by considering a challenge for the gesture-first theory: why speech is the primary communication modality of modern humans.