The results challenge existing theories and bring into question the long-held assumption that patterns of social interactions in chimpanzees and other primates reflect relationships that themselves indicate a level of trust between individuals.
The research was conducted by Dr Nicholas E. Newton-Fisher and colleague Dr Stefano Kaburu from Kent’s School of Anthropology and Conservation. Published by the journal Scientific Reports (Nature Publishing Group), it reveals the clear influence of bystanders on grooming decisions, and, intriguingly, that such decisions did not appear to be based on prior grooming interactions.
It also found that with more bystanders – a larger audience – male chimps offered less grooming at the start of a bout, were more likely to abandon attempts to start a grooming interaction, and that their grooming efforts were less likely to be reciprocated.
The results suggest that the chimps’ decisions on how much to invest in grooming interactions are based at least in part on whether there are other potential social partners close by.
For more read Chimpanzee grooming-You Scratch My Back