BLOOD is not necessarily thicker than water, say scientists who have been studying the behaviour of monkeys.
University of Portsmouth psychologists have been researching the tendency of monkeys to follow the gaze of their companions to see what they are looking at.
PhD student Jerome Micheletta and Dr Bridget Waller say their research into crested macaques suggests friends come first.
They observed that all macaques followed the gaze of their companions whether they were a friend, a family member or a group leader.
But when it came to following the gazes of friends, the reaction was much faster than when it was a family member.
Mr Micheletta says the findings are exciting as they are the first to prove friendship has such a pivotal role in the social behaviour of monkeys and probably humans.
He said: ‘Gaze following is strongly influenced by the degree of friendship between the macaques.
‘Friends reacted much faster to friends’ gazes regardless of the subtlety or lack of it in the informants’ movements.’
Gaze following depends on the situation and relationship between animals, and is known to take place in a range of species including humans, chimpanzees, goats and tortoises.
But until now the dynamics of how it works in social groups have been poorly understood.
Mr Micheletta added: ‘We don’t know why they do it.
‘It could be that information relevant to your friends is also more relevant to you.
‘It could be that you don’t have too much competition between friends, or that you like paying more attention to friends.
‘It’s thought gaze following helps individuals learn valuable things about their social and physical environment by providing clues about the location of something interesting, whether that be food, a threat or something else.’