Abstract

Foragers, such as the Agta are highly cooperative, thus are prime study populations for exploring communal breeding from an evolutionary perspective. Due to the labour-intensive nature of observational studies, previous studies have suffered from small sample sizes, necessarily limiting analysis. Thus, many questions have been left unexplored. This research uses innovative methodological techniques to produce high-resolution interaction networks for 200 Agta. Who interacts with whom is monitored every two minutes for a one week period, producing over 2,000 allomother-child dyads. I test alternative hypotheses for why ‘selfish’ individuals provide costly childcare, finding a role for reciprocal cooperation and juvenile playgroups. I also leverage on the lifestyle variability within the Agta and explore how childcare varies in different scenarios. I find that care reduces with increased disease and mortality risk associated with the occurrence in settled agriculture.