By Michelle Warwicker
Scientists have provided insight into why unrelated chimpanzees co-operate with each other outside a sexual relationship.
The team of international researchers found that increased levels of the hormone oxytocin played an intrinsic role in non-kin co-operation.
Wild chimps that had taken part in a grooming session with a “bond partner” had higher levels of the hormone in their urine than after grooming with a “non-bond partner”, irrespective of whether the individuals were related.
Results of the study are published in the journal Proceedings of the Royal Society B.
Read more at: BBC Nature