NEW YORK, Nov 19 (Reuters) - Forty- and 50-somethings in the
throes of a mid-life crisis should probably stop blaming a
troubled marriage, their kid's college costs, or technology that
makes them feel about as modern as papyrus compared to their
younger colleagues.
A new study finds that chimpanzees and orangutans, too,
often experience a mid-life crisis, suggesting the causes are
inherent in primate biology and not specific to human society.
"We were just stunned" when data on the apes showed a
U-shaped curve of happiness, said economist Andrew Oswald of the
University of Warwick in England and a co-author of the paper,
which was published on Monday in the Proceedings of the National
Academy of Sciences of the USA.
The U-shaped curve of human happiness and other aspects of
well-being are as thoroughly documented as the reasons for it
are controversial. Since 2002 studies in some 50 countries have
found that well-being is high in youth, plunges in mid-life and
rises in old age. The euphoria of youth comes from unlimited
hopes and good health, while the contentment and serenity of the
elderly likely reflects "accumulated wisdom and the fact that
when you've seen friends and family die, you value what you
have," said Oswald.
The reasons for the plunge in well-being in middle age, when
suicides and use of anti-depressants both peak, are murkier. In
recent years researchers have emphasized sociological and
economic factors, from the accountant's recognition that she
will never realize her dream of starring on Broadway to the
middle manager's fear of being downsized, not to mention failing
marriages and financial woes.
In what Oswald, 58, calls "a burst of madness," since no
such study had ever been attempted, he and his colleagues
decided to see whether creatures that don't have career regrets
or underwater mortgages might nevertheless suffer a well-being
plunge in middle age.
They enlisted colleagues to assess the well-being of 155
chimps in Japanese zoos, 181 in U.S. and Australian zoos and 172
orangs in zoos in the United States, Canada, Australia and
Singapore. Keepers, volunteers, researchers and caretakers who
knew the apes well used a four-item questionnaire to assess the
level of contentment in the animals, said psychologist Alex
Weiss of Scotland's University of Edinburgh. One question, for
instance, asked how much pleasure the animals - which ranged
from infants to graybeards - get from social interactions.
All three groups of apes experienced mid-life malaise: a
U-shaped contentment curve with the nadir at ages 28, 27 and 35,
respectively, comparable to human ages of 45 to 50.
Why would chimps and orangs have a mid-life crisis? It could
be that their societies are similar enough to the human variety
that social, and not only biological, factors are at work,
Oswald said. Perhaps apes feel existential despair, too, when
they realize they'll never be the alpha male or female.
An evolutionary explanation is even more intriguing. "Maybe
nature doesn't want us to be contented in middle age, doesn't
want us sitting around contentedly with our feet up in a tree,"
he said. "Maybe discontent lights a fire under people, causing
them to achieve more" for themselves and their family.
"By knowing our results, people might be gentler on
themselves" when they experience a mid-life crisis, Oswald said.
"Knowing that it's biological, they'll realize that if they can
just hang on they'll likely come out the other side."
(Editing by James Dalgleish)