It is inevitable. The muscles weaken. Hearing and vision fade.
We get wrinkled and stooped. We can't run, or even walk, as fast as before. We have aches and pains in parts of our bodies we never noticed before. We get old.
It sounds miserable, but apparently it is not. A Gallup Poll has found that by almost any measure, people get happier as they get older, and researchers are not sure why.
"It could be that there are environmental changes," said Arthur A. Stone, the lead author of a study based on the survey, "or it could be psychological changes about the way we view the world, or it could even be biological -- for example, brain chemistry or endocrine changes." The phone survey, carried out in 2008, covered more than 340,000 people nationwide, ages 18 to 85, asking questions about age and sex, current events, personal finances, health, and other matters.
The survey asked about "global well-being" by having each person rank overall life satisfaction on a 10-point scale, an assessment many people may make from time to time, if not in a formalized way.
Finally, there were six yes-or-no questions: Did you experience the following feelings during a large part of the day yesterday: enjoyment, happiness, stress, worry, anger, sadness. The answers, the researchers say, reveal "hedonic well-being," a person's immediate experience of those psychological states, unencumbered by revised memories or subjective judgments that a query about general life satisfaction might have evoked.
The results, published online May 17 in the Proceedings of the National Academy of Sciences, were good news for old people, and for those who are getting old. On the global measure, people start out at age 18 feeling pretty good about themselves, and then, apparently, life begins to throw curveballs. They feel worse and worse until they hit 50. At that point, there is a sharp reversal, and people keep getting happier as they age. By the time they are 85, they are even more satisfied with themselves than they were at 18.
In measuring immediate well-being, or yesterday's emotional state, the researchers found that stress declines from age 22 on, reaching its lowest point at 85. Worry stays fairly steady until 50, then sharply drops. Anger decreases steadily from 18 on, and sadness rises to a peak at 50, declines to 73, then rises slightly again to 85. Enjoyment and happiness have similar curves: They decrease gradually until we hit 50, rise steadily for the next 25 years, and then decline very slightly at the end, but they never again reach the low point of our early 50s.
'Something very deep'
Other experts were impressed with the work. Andrew J. Oswald, a professor of psychology at Warwick Business School in England, who has published several studies on human happiness, called the findings important and, in some ways, heartening.
"It's a very encouraging fact that we can expect to be happier in our early 80s than we were in our 20s," he said. "And it's not being driven predominantly by things that happen in life. It's something very deep and quite human that seems to be driving this."
Stone, who is a professor of psychology at the State University of New York at Stony Brook, said that the findings raised questions that need more study.
What happens at 50?
"These results say there are distinctive patterns here," he said, "and it's worth some research effort to try to figure out what's going on. Why at age 50 does something seem to start to change?"
The study was not designed to figure out which factors make people happy, and the poll's health questions were not specific enough to draw conclusions about the effect of disease or disability on happiness in old age. But the researchers looked at four possibilities: the sex of the interviewee, whether the person had a partner, whether there were children at home and the person's employment status.
"These are four reasonable candidates," Stone said, "but they don't make much difference."
For people younger than 50 who may sometimes feel gloomy, there may be consolation here. The view seems a bit bleak right now, but look at the bright side: You are getting old.