A curious story has emerged which suggests new research shows chimps and orang-utans also have a ‘midlife crisis’. The Daily Telegraph picks up the story:
Human behaviour studies have revealed the well-established trend that our level of happiness declines after childhood until middle age, when we gradually begin to feel more content again.
Now researchers have found that the same “u-shaped” pattern is also seen among chimpanzees and orang-utans, who are most satisfied with life in their earliest and latest years but reach a “nadir” in middle age.
The researchers examined behavioural reports on more than 500 captive apes compiled by their keepers, researchers or other volunteers who were familiar with them throughout their lives.
Writing in the Proceedings of the National Academy of Sciences journal, they reported that the animals’ happiness was generally high in youth, declined in middle age and rose again into old age.
While the study does not rule out the influence of cultural forces on our mood, it suggests biological factors could partly explain the distinctive u-shaped pattern.
Possible explanations could be that happiness is linked to longevity – meaning that the humans and apes who live longest are likely to be the happiest – or that brain changes as we age influence our well-being.
A third explanation could be that older humans and apes spend more time doing things that they enjoy, or set themselves more attainable goals in order to feel more satisfied, researchers said.
Robin Dunbar, professor of evolutionary psychology at Oxford University, was dubious about the findings. “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, was also sceptical. She said the concept of a midlife crisis was shaky even in humans. “In my reading of the literature, there is no evidence for the midlife crisis. 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.”