When people begin to worry about their mortality, they might fight the blues by buying a fancy sports car, having an affair, or even wearing a toupee. But, what is a great ape to do? This not a frivolous question because an international team of researchers has found that some of our closest primate relatives–chimpanzees and orangutans–also suffer from midlife crises. Psychologists have long observed that humans have U-shaped happiness curves over the course of their lives, meaning that their sense of well-being is high in their youth, declines during middle age, and rallies again later in life and it now appears that great apes follow the same pattern.
In a new study, keepers and volunteers at zoos and sanctuaries in five countries filled out questionnaires based on observations of their apes, chimpanzees and orangutans. They were asked to rate the mood of their charges, assess the pleasure that each ape gets from social situations, and consider how successful each animal is in achieving its goals. Keepers were even encouraged to imagine how happy they would be if they lived in an ape’s shoes–or, rather, their five-toed grasping feet–for a week.
One of the researchers, Professor Andrew Oswald of the University of Warwick, noted: “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. Apes also have a pronounced midlife low, and they have none of those.”
The study was published in the Proceedings of the National Academy of Sciences.
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