From hands to concepts: evolutionary and developmental origins of gesture iconicity

The GESTICO project will explore the developmental and evolutionary origins of gestural iconicity, by examining the spatial properties of gestures that convey meaning independently of semantic communication. The relevance of different amplitudes and lateralisation of gestures in reference to spatio-numerical and/or emotional magnitudes will be tested in non-human primates (Chimpanzees, Bonobos, Guinea baboons, and Barbary macaques) and preverbal human infants. Observational data from chimpanzees and bonobos will be used to investigate whether the amplitude and laterality of their communicative gestures are meaningful, by testing their correlation with specific social or emotional contexts, and whether they impact the responses of recipients (WP1). Movement analyses, based on newly developed deep learning tools, will be used to enable quantitative measures on gestures. Once the methodology of gesture spatialisation description is established for great apes, similar analyses will be applied to gestures of captive Guinea baboons and Barbary macaques (WP2). Finally, a habituation paradigm measuring looking times will assess the ability of human infants aged 10 to 12 months to spontaneously associate concepts of magnitude (quantities) with metaphorical manual gestures differing in their spatial amplitude (WP3).Collaboration between the host organisation, the Wild Minds Lab (University of St Andrews), the Eco-Anthropology Lab (French National Museum of Natural History), and the Integrative Neuroscience and Cognition Center (Paris Cité University) will facilitate an interdisciplinary approach, enabling cross-species comparisons around common concepts. The complementary use of innovative observational and experimental approaches will contribute to a better understanding of the emergence of the form-function link in the gestural communication of catarrhine primates (Afro-Eurasian species, including humans), and the associated cognitive mechanisms.