Chimpanzee Midlife Crises and Orangutans Going Ape

New research shows great apes suffer midlife crises and freed orangutans go ape

Posted Nov 21, 2012

As usual, when I go to my email inbox there are many new messages about the latest and greatest research on the fascinating lives of nonhuman animals (animals). 

Now we know that just like human animals, chimpanzees and other great apes seem to suffer from midlife crises. A study of 336 chimpanzees and 172 orangutans suggests these crises may be driven by biological factors. This is not at all surprising given how much of our DNA and neurobiological apparatus we share with our nonhuman relatives.

Researchers note, "If our animal relatives share our propensity for sadness, withdrawal and frustration at life's midpoint, perhaps the midlife crisis is actually driven by biological factors—not the wearing responsibilities of jobs and family and the dawning recognition of our mortality." The abstract for the original study published in the highly prestigious journal Proceedings of the National Academy of Sciences (PNAS) reads as follows: 

Recently, economists and behavioral scientists have studied the pattern of human well-being over the lifespan. In dozens of countries, and for a large range of well-being measures, including happiness and mental health, well-being is high in youth, falls to a nadir in midlife, and rises again in old age. The reasons for this U-shape are still unclear. Present theories emphasize sociological and economic forces. In this study we show that a similar U-shape exists in 508 great apes (two samples of chimpanzees and one sample of orangutans) whose well-being was assessed by raters familiar with the individual apes. This U-shaped pattern or “midlife crisis” emerges with or without use of parametric methods. Our results imply that human well-being’s curved shape is not uniquely human and that, although it may be partly explained by aspects of human life and society, its origins may lie partly in the biology we share with great apes. These findings have implications across scientific and social-scientific disciplines, and may help to identify ways of enhancing human and ape well-being.

Midlife crises cross cultures and seem to be a universal factor for humans all over the world, and biological factors are essential to consider in addition to economic and sociological variables. One of the co-authors of this landmark study, Andrew Oswald, a behavioral economist at the University of Warwick in England, notes, "for forlorn midlifers, the study is a happy reminder that while humans may be programmed to suffer a dip in pleasure, it gets better. 'This suggests that it's completely normal, and that it's apparently out of your control.'"

I wouldn't be at all surprised to learn that other animals also suffer from midlife crises at the appropriate age in their life cycles. There are sound biological reasons for making this claim. Charles Darwin stressed that variations among species are differences in degree rather than kind. There are shades of gray, not black and white differences, so if we have something, "they" (other animals) have it too. This is called evolutionary continuity, and it shows that it is bad biology to overlook the traits other animals clearly possess and share with us. We need to keep an open mind about the emotional lives of other animals.

"Overjoyed orangutans go ape as they are released into the wild for the very first time": Rewilding and going home at last

Orangutans are also in the news. And this is great news. Earlier this month, 21 orangutans—five mothers and their 16 babies—were released into the wild at the Bukit Batikap Conservation Forest in Indonesia, and their reactions—joyful, uncertain, apprehensive—were all caught on camera. The pictures and video are among the most amazing I've seen in a long while. 

Here's a teaser photo of Leonora and her baby Lamar who "needed no encouragement to jump in the crate to the release area and were the only orangutans who didn't need sedation for the plane and helicopter journey."

Leonora and her baby Lamar

This is wonderful news and gives hope that many other captive animals will be able to be "rewilded" and allowed to go home. 

Stay tuned for more from the most fascinating and amazing world of animals.

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