What do the very first writhing movements of babies have in common with orangutans solving problems for food? Well, according to Gillian Forrester they may both offer clues about how we humans developed language. Working with her great ape colleagues, Gilly Forrester – Professor of Comparative Cognition at the University of Sussex – has dedicated her career to finding out how we became the talkative, tool-using troop we are today. Examining the link between movement, spoken language and social communication, Gilly’s research has looked at how brain organisation could affect the likelihood of being diagnosed with autism and ADHD, as well as how training dexterity may improve linguistic fluency in children. In conversation with Professor Jim Al-Khalili, Gilly reveals what she believes it really means to be human, and the pair discover that despite his PhD in nuclear physics, Jim might not be quite as smart as a chimp. Presented by Jim Al-Khalili