Dr Gillian Forrester - Hand and Mouth: What motor laterality reveals about the origins of human language

The investigation of modern human cognitive function requires a dual perspective because the evolution and development of language processes are inextricably linked. It is widely accepted that humans demonstrate population-level right-handedness, linked with dominant left hemisphere control of language processes. However, a species-unique, causal relationship is debated. Language features such as simple syntactic structures and hierarchical organisation may derive from behaviours inherited from a last common ancestor of humans and apes. A shared history of left cerebral dominance for hand and mouth motor articulation may explain why humans and great apes express population-level right hand dominance for the production of gesture and the manipulation of objects. The following presentation will focus on recent behavioural evidence from great apes and children.