Apes 'have a mid-life crisis too': what it means for humans
If apes suffer mid-life crises, it suggests ours have nothing to do with mortgages or divorce
GREAT APES held in captivity are prone to mid-life crises, researchers have suggested. If true, the findings suggest there is an evolutionary explanation for the well-documented phenomenon of 40-something family men buying impractical but fast cars.
Economists and behavioural scientists have already offered proof in previous studies that the happiness and wellbeing of humans is high in youth, falls to a low in mid-life and then rises again in old age.
To see if the same is true in our closest mammalian cousins, scientists studied 508 chimpanzees and orang-utans of different ages from zoos, sanctuaries and research centres, reports the BBC.
People familiar with the apes, such as zookeepers, rated their well-being using a questionnaire. The researchers found that apes' happiness followed the same U-curve as humans, suggesting that other primates can also go through a mid-life crisis.
Psychologist Dr Alexander Weiss of the University of Edinburgh, lead author of the paper, which is published in the Proceedings of the National Academy of Sciences, said: "You don't have the chimpanzee hitting mid-life and suddenly they want a bright red sports car.
"But there may be other things that they want, like mating with more females or gaining access to more resources."
He added that we must look deeper into our evolutionary past and determine what is similar in middle-aged humans, chimps and orang-utans if we want to explain the mid-life crisis.
Study co-author and economics professor Andrew Oswald of Warwick University told The Daily Telegraph that the research showed the answer to the question of why human happiness follows an approximate U-shape through life “cannot be because of mortgages, marital break-up, mobile phones, or any of the other paraphernalia of modern life. Apes also have a pronounced midlife low, and they have none of those".
Some scientists are sceptical of the findings, however.
Robin Dunbar, professor of evolutionary psychology at Oxford University told The Guardian: "What can produce a sense of wellbeing or contentedness that varies across the lifespan like this? It's hard to see anything in an ape's life that would have that sort of pattern, that they would cogitate about. They're not particularly good at seeing far ahead into the future, that's one of the big differences between them and us."
Alexandra Freund, professor of psychology at the University of Zurich, said that the existence of mid-life crises is unproven even in humans. "In my reading of the literature, there is no evidence for the midlife crisis,” she said. “If there's any indication of decline in emotional or subjective wellbeing it is very small and in many studies, it's not there at all."