For centuries, sages have alluded to a richness in life's later years that is lost on the young. But only in the l ast decade have researchers begun to measure happiness across the life span and, in doing so, try to understand why older people tend to be so content.
The explanation doesn't appear to be biological -- some chemical in the brain that mellows us just when all those plump neurons needed for thinking and memory are shrivelling up. Rather, most scientists now think that experience and the mere passage of time gradually motivate people to approach life differently.
The blazing-to-freezing range of emotions experienced by the young blends into something more lukewarm by later life, numerous studies show. Older people are less likely to be caught up in their emotions and more likely to focus on the positive, ignoring the negative.
" When you have that disaster at 10 in the morning, you can deal with it better when you're older," says Stacey Wood, a neuropsychologist and associate professor at Scripps College in Claremont, Calif.
In a study published in September in Psychological Science, Wood and her collaborator, neuroscientist Michael Kisley of the University of Colorado, recorded the brain activity of 63 adults, ranging in age, who were shown a series of negative and positive images, such as dead animals or a bowl of ice cream. Older adults were about 30 percent less reactive to the negative images compared with the younger adults.
Other studies have found similar results -- that older people experience negative emotion less often and recover from it more quickly.
"What we see is a real difference in how negative information is processed by the brain," Wood says. "When we talk about maturity or wisdom, we're talking about that ability to integrate negative emotion or cognitive information; being able to weigh it and not find it so disruptive."
Why people regulate their emotions better as they age may be due in part to school-of-hard-knocks experience. Eventually they learn the world will not end when the car breaks down or the child gets strep throat.
One of the first researchers to discover that older people tend to be happier thinks there's another reason for this greater emotional control. It's linked to a person's sense of time. Older people are aware that life doesn't last forever -- and, with a finite amount of time ahead , they think it should be well spent.
In a study at Stanford University's Center on Longevity, psychologist Laura Carstensen showed that people who perceived their future time as limited had goals that were emotionally meaningful. People who perceived their futures as open-ended had goals that tended to be knowledge-related. Carstensen concluded that, as people age, they encounter "shrinking time horizons."
An appreciation of remaining time leads older people to be more grateful for what they have, Carstensen and other researchers say. And being thankful is great for mental health.
Studies by Robert A. Emmons, a psychology professor at the University of California, Davis, show that people who focus on what they are grateful for have better emotional well-being, especially a positive mood, compared with people who focus on the negative or neutral information.
Combining the mental shrewdness of youth with the ability to savor life might be a successful recipe for contented living -- whatever one's age. "If only younger people could step out of themselves and focus on the positive and realize life is fragile and life is valuable," Carstensen says. "And if older people could think about the future and worry a little bit more, that's good."
