Handedness in captive bonobos (Pan paniscus)

Area of Science:

• Primate behavior
• Evolutionary biology
• Neuroscience

Background:

• Species-level right-handedness is a hallmark of humans, often linked to language evolution.
• The evolutionary origins of handedness and its connection to cognitive abilities remain areas of active research.
• Bonobos (Pan paniscus) are closely related to humans, making them a valuable model for comparative studies.

Purpose of the Study:

• To investigate the presence or absence of species-level handedness in bonobos (Pan paniscus).
• To explore the implications of bonobo handedness for understanding the evolution of human handedness and language.
• To determine if handedness in non-human primates can serve as an indicator of language-related cognitive abilities.

Main Methods:

• Observational study of handedness in three captive groups of bonobos.
• Assessment of reaching and grasping behaviors to determine hand preference.
• Statistical analysis of handedness data across 22 individual bonobos.

Main Results:

• No statistically significant evidence for species-level right-handedness was found in the studied bonobo groups.
• Individual bonobos exhibited varying degrees of hand preference, but no consistent pattern emerged at the species level.
• The findings indicate a lack of population-level right-handedness in bonobos.

Conclusions:

• Species-level right-handedness likely evolved after the evolutionary divergence of the Pan and Homo lineages.
• Inconsistent hand preferences observed in bonobos might represent ancestral precursors to the more fixed human handedness.
• While bonobos may possess language-related cognitive capacities, handedness in its current form is not a reliable indicator for measuring these abilities in Pan species.