Chimpanzees going through a midlife crisis? It sounds like a setup for a joke.
But there it is, in the title of a report published Monday in a scientific journal: "Evidence for a midlife crisis in great apes."
So what do these apes do? Buy red Ferraris? Leave their mates for someone younger?
"I believe no ape has ever purchased a sports car," said Andrew Oswald, an author of the study. But researchers report that captive chimps and orangutans do show the same low ebb in emotional well-being at midlife that some studies find in people.
That suggests the human tendency toward midlife discontent may have been passed on through evolution, rather than resulting simply from the hassles of modern life, said Oswald, a professor of economics at the University of Warwick in England who presented his work in the Proceedings of the National Academy of Sciences.
Several studies have concluded that happiness in human adults tends to follow a certain course between ages 20 and 70: It starts high and declines over the years to reach a low point in the late 40s, then turns around and rises to another peak at 70. On a graph, that's a U-shaped pattern. Some researchers question whether that trend is real, but to Oswald the mystery is what causes it.
When he learned that others had been measuring well-being in apes, "it just seemed worth pursuing the hunch that the U might be more general than in humans," he said.
He and his co-authors say they found that the familiar U-shaped curve exists in apes.
"We find it for these creatures that don't have a mortgage and don't have to go to work and don't have marriage and all the other stuff," Oswald said. "It's as though the U shape is deep in the biology of humans" rather than a result of uniquely human experiences.