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Published on: May 5, 2015
Tolerance allows bonobos to outperform chimpanzees on a cooperative task
Brian Hare1, Alicia P Melis, Vanessa Woods
1Max Planck Institute for Evolutionary Anthropology, D-04103 Leipzig, Germany. hare@eva.mpg.de
Current Biology : CB
|March 10, 2007
Summary
Bonobos cooperate more successfully than chimpanzees in solving social problems, especially when rewards are monopolizable. This suggests that selection on emotional reactivity influences cooperative abilities in species, including hominoids.
Area of Science:
- Primate Behavior
- Evolutionary Psychology
- Comparative Cognition
Background:
- Understanding the evolution of cooperation is crucial for explaining social behavior in various species.
- Two hypotheses exist: the "emotional-reactivity hypothesis" suggesting higher tolerance in bonobos aids cooperation, and the "hunting hypothesis" proposing chimpanzee success due to cooperative hunting experience.
- Emotional reactivity, influenced by domestication, may play a role in social problem-solving abilities.
Purpose of the Study:
- To compare the cooperative food-retrieval abilities of bonobos and chimpanzees.
- To test the "emotional-reactivity hypothesis" against the "hunting hypothesis" by examining cooperation under different conditions.
- To investigate the link between emotional reactivity, social tolerance, and cooperative success.
Main Methods:
- Assessed emotional reactivity by measuring social tolerance during cofeeding in bonobos and chimpanzees.
- Observed and compared cooperative food retrieval in tasks with varying monopolizability of rewards.
- Quantified differences in social tolerance, socio-sexual behavior, and play during cofeeding.
Main Results:
- Bonobos exhibited higher social tolerance and more socio-sexual behavior and play during cofeeding compared to chimpanzees.
- In tasks with low monopolizability, bonobos and chimpanzees showed equal cooperation.
- Bonobos were more successful than chimpanzees in cooperative food retrieval when rewards were highly monopolizable.
Conclusions:
- Results support the "emotional-reactivity hypothesis," indicating that bonobos' higher tolerance contributes to greater cooperative success in certain contexts.
- Selection on temperament, specifically emotional reactivity, appears to be a significant factor explaining variations in cooperative abilities among species, including hominoids.
- This study highlights the role of inherent social tolerance in shaping the evolution of cooperation.
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