Evidence of ’mid-life’ crisis in Great Apes

Chimpanzees and orangutans can experience a mid-life crisis just like humans, a study suggests. This is the finding from a new study that set out to test the theory that the pattern of human well-being over a lifespan might have evolved in the common ancestors of humans and great apes. An international team of researchers, including economist Andrew Oswald from the Department of Economics at the University of Warwick and psychologist Alex Weiss from the University of Edinburgh, discovered that, as in humans, chimpanzee and orangutan well-being (or happiness) follows a U shape and is high in youth, falls in middle age, and rises again into old age. The authors studied 508 great apes housed in zoos and sanctuaries in the United States, Japan, Canada, Australia and Singapore. The apes' well-being was assessed by keepers, volunteers, researchers and caretakers who knew the apes well. Their happiness was scored with a series of measures adapted from human subjective well-being measures. Oswald said: "We hoped to understand a famous scientific puzzle: why does human happiness follow an approximate U-shape through life? We ended up showing that it cannot be because of mortgages, marital breakup, mobile phones, or any of the other paraphernalia of modern life.