Like old ape, like old human ...

Psychologists at the University of Zurich and the German Primate Centre in Goettingen conducted a study of the social life of monkeys as they age. Published in Current Biology (June 2016), the researchers documented their study on the influence of age on the behaviour of more than 100 Barbary macaque monkeys living in an enclosed 50-acre park in southern France.

Researchers studied how the monkeys, ranging in age from 4-29 years (equivalent to about 105 ‘human years’), responded to physical objects (like toys), social interactions (grooming each other, fighting etc.), and social information (photographs or vocal sounds that indicate a ‘friend’ or a ‘stranger’).

Results showed that the apes became less interested in toys as they entered their reproductive years.

At around 20 years (their old age), monkeys preferred less contact with each other, and approached other apes less frequently. This was not because younger monkeys rejected the older monkeys (younger monkeys still approached and groomed their elders). Instead, older monkeys made the choice to withdraw socially. Older monkeys still responded to photographs of other monkeys and hissed at each other during fights. Hence, they knew what was happening in their community, but they did not want to participate in the activities of other monkeys.

Researchers said that they saw the same behaviours in older humans – like old ape, like old human. Researchers said that it is because as apes age, and as humans age, they become more selective (more choosy or more picky) about their interactions with others – and more selective about how they use their time. 

It could be due to the lack of stamina as they age – they may become ‘too tired’ to deal with relationships that are ambivalent or negative. Or maybe older monkeys are less socially interactive because they tend to take fewer risks. Whatever the reason, older apes made a conscious and deliberate choice to have fewer social interactions within their community.

http://www.nytimes.com/2016/06/24/science/old-monkeys-picky-behavior.html?module=WatchingPortal&region=c-column-middle-span-region&pgType=Homepage&action=click&mediaId=wide&state=standard&contentPlacement=10&version=internal&contentCollection=www.nytimes.com&contentId=http%3A%2F%2Fwww.nytimes.com%2F2016%2F06%2F24%2Fscience%2Fold-monkeys-picky-behavior.html&eventName=Watching-article-click&_r=0

MARTINA NICOLLS is the author of:- The Shortness of Life: A Mongolian Lament (2015), Liberia’s Deadest Ends (2012), Bardot’s Comet (2011), Kashmir on a Knife-Edge (2010) and The Sudan Curse (2009).