Bonobo's cooperation in a free group choice experiment

Abstract

The concept of cooperation has been explored and defined by various scholars across disciplines, revealing the complexity and nuanced nature of this fundamental behaviour. The aim of this work is to investigate the cooperative behaviours of bonobos (Pan paniscus) using a modified loose-string paradigm in a group context, alongside examining the relationship quality among bonobo dyads. The study was conducted at the Planckendael Zoo in Mechelen, Belgium, focusing on a population of bonobos. The study included a total of 22 individuals, housed into two groups, with 11 adult or adolescent females, 6 adult or adolescent males, and 5 juveniles. Relationship quality was assessed based on eight behavioural variables, yielding scores for Relationship Value and Incompatibility. The results indicate that genetic sex combinations significantly influence relationship Value, with higher scores observed in female-female and mother-offspring dyads. In this study, the age difference did not affect the relationship quality. The cooperation experiment involved 240 trials, with a 11% success rate. Individual performance varied, with factors such as motivation, task understanding, and social dynamics playing critical roles in successful cooperation. Additionally, behavioural inhibition and attention to partners were identified as crucial factors influencing cooperative success. The findings did not fully support the self-domestication hypothesis but aligned with the cooperative breeding hypothesis, suggesting limited prosociality among bonobos due to their reproductive strategies. The empathy hypothesis also provided some insights, indicating that bonobos' ability to understand the needs and feelings of others might contribute to cooperative success. Bonobos exhibited difficulty in waiting for partners, often leading to premature actions and failure in cooperative tasks. This behaviour suggests a need to better understand the cognitive mechanisms underpinning cooperation In conclusion, this study provides insights into the cooperative behaviours of bonobos, emphasizing the importance of social relationships and individual differences. Future research should explore the long-term effects of cooperative tasks on social dynamics, incorporate methods to enhance motivation, and consider the impact of individual personality traits and past experiences on cooperation.