Periodic Reporting for period 4 - JOINTATT (The evolutionary and developmental origins of Joint Attention: a longitudinal cross-species and cross-cultural comparison)
Periodo di rendicontazione: 2022-01-01 al 2022-12-31
Humans frequently coordinate and share attention about objects and events. Our basic ability to engage in joint attention (JA) is thought to underpin our uniquely complex cooperation skills and language, raising the possibility that the emergence of JA was a ‘small change that made a big difference’ in the evolution of human cognition. Despite the theoretical importance of JA for understanding human social cognition, we know surprisingly little about JA across species and cultures. Methodological shortcomings limit our understanding of the extent to which JA is uniquely human or shared with our primate cousins, and we lack data on how this ability develops in non-western cultures, which aspects of the social environment are necessary for JA to emerge and how JA is related to the emergence of cooperation. The JOINTATT project will address these four key issues by collecting longitudinal data on mother-infant dyads over the first 2 years of the infant’s life, across four different study groups: Ugandan and British humans; wild chimpanzees and crested macaque monkeys. The project will develop novel tasks and measures that allow the same set of data to be collected in directly comparable ways across species and provide the first valid, rigorous test of whether engagement in JA is a uniquely human trait. Data from the two human groups will test how different elements of JA are related and whether JA develops in a uniform way across cultures. Longitudinal data on mother-infant interactions and the infant’s environment will be related to performance on JA tasks across all four groups, enabling us to identify conditions that are likely necessary for JA to emerge. Performance on JA and cooperative tasks will be compared to assess whether engagement in JA predicts the later emergence of cooperation. This project will provide ground-breaking insights into JA and its evolutionary origins, and is likely to challenge current theories of how human social cognition evolved.
In the first 4 years of this grant, we have designed a battery of tasks to test joint attention in a directly comparable way across our four study populations and implemented a raft of observational data collection to capture the socio-ecological environment in which our infants are developing. We have recruited and collected longitudinal data over the first two years of life on 48 UK mother-infant pairs, 46 Ugandan mother-infant pairs, 37 wild chimpanzee mother-infant pairs and 17 wild crested macaque monkey mother-infant pairs. Unfortunately Covid-19 disrupted data collection, so we are now following up with our human cohorts when they are 4-5 years old to take final measures of cooperaation and prosocial behaviours. This final stage of data collection will be complete by the end of the grant (extended to December 2022). Whilst several of our main research questions cannot be addressed until we have the full dataset collected, we have these initial findings to report: (1) Operational definitions of joint attention events need to include explicit measures of behaviour as the quality of looks exchanged by mothers and infants cannot be reliably judged by observers (published in PLOS One); (2) Cultural variation found in infant early life experience in our UK and Ugandan samples (in review at PLOS One; Holden thesis chapter); (3) Evidence of a proto-declarative 'showing' gesture in wild chimpanzees (to be submitted to Current Biology in March 2022); (3) Cultural variation in the acoustic characteristics of infant directed speech in UK and Ugandan samples (to be submitted to Child Development by April 2022); (4) Evidence of Joint attention events in non-human primates using a strict operational definition, which challenge the assumption that these are uniquely human, but evidence that when given the same stimulus human mother-infant dyads engage in significantly more joint attention events than non-human primates (Lahiff thesis chapter); (5) Prosocial helping is more likely to occur in 18 month old Ugandan infants than UK infants, despite UK mothers offering more explicit scaffolding (Buryn-Weitzel, thesis chapter) and (6) Prosocial sharing of resources is equally likely to occur in 18-month old Ugandan and UK infants, depsite more explicit scaffolding from UK mothers (Buryn-Weitzel, thesis chapter).
We are generating an extremely rich and detailed dataset on the development of the infants in our study, which, when the data set is complete, will allow us to address all our key research questions and hopefully many more. Our cross-species, cross cultural approach will give us unique power to examine the evolutionary and ontogenetic roots of joint attention.