'Hippy apes' as aggressive as chimps

Washington - Historically considered a more peaceful species than their chimpanzee cousins, bonobos are actually just as aggressive - but target their ire most often at males, according to a study published on Wednesday.

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Living in matriarchal societies, the gentle-eyed primates once dubbed "hippy apes" are far from violence-free, a group of European researchers reported in the journal Science Advances.

They studied 13 groups of bonobos and nine groups of chimpanzees - who conversely live in patriarchal systems and are well-known for their aggressivity - in zoos, seeking to find out which is more prone to attacks.

Measuring different types of aggressive behaviour, both physical and not - such as throwing objects, intimidation, or biting and slapping - they found "no overall differences in absolute aggression rates between the two species".