NEW YORK — 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 this month in a scientific journal: ‘‘Evidence for a midlife crisis in great apes.’’
The researchers reported that captive chimps and orangutans 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 Andrew Oswald, an author of the study.
Oswald, a professor of economics at the University of Warwick in England, 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, creating a U-shaped curve.
Oswald and coauthors assembled data on 508 great apes from zoos and research centers in the United States, Australia, Canada, Singapore, and Japan. Caretakers and other observers had filled out a four-item questionnaire to assess well-being in the apes.
The questions asked such things as the degree to which each animal was in a positive or negative mood, how much pleasure it got from social situations, and how successful it was in achieving goals.
Oswald and his co-authors say they found that the survey results produced that familiar U-shaped curve, adjusted to an ape’s shorter lifespan.