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).
