NEW YORK — As a motivational speaker and executive coach, Caroline Adams Miller knows a few things about using mental exercises to achieve goals. But last year, one exercise she was asked to try took her by surprise.
Every night, she was to think of three good things that had happened that day and analyze why they had occurred. That was supposed to increase her overall happiness.
"I thought it was too simple to be effective," said Miller, 44, of Bethesda. Md. "I went to Harvard. I'm used to things being complicated."
Miller was assigned the task as homework in a master's degree program. But as a chronic worrier, she knew she could use the kind of boost the exercise was supposed to deliver.
She got it.
"The quality of my dreams has changed, I never have trouble falling asleep and I do feel happier," she said.
Results may vary, as they say in weight-loss ads. But that exercise is one of several that have shown preliminary promise in recent research into how people can make themselves happier -- not just for a day or two, but long-term. It's part of a larger body of work that challenges a long-standing skepticism about whether that's even possible.
There's no shortage of advice in how to become a happier person, as a visit to any bookstore will demonstrate. In fact, Martin E.P. Seligman of the University of Pennsylvania and colleagues have collected more than 100 specific recommendations, ranging from those of the Buddha through the self-improvement industry of the 1990s.
The problem is, most of the books on store shelves aren't backed up by rigorous research, says Sonja Lyubomirsky, a psychologist at UC Riverside who's conducting such studies now. (She's also writing her own book.)
In fact, she says, there has been very little research in how people become happier.
Why? The big reason, she said, is that many researchers have considered that quest to be futile.
For decades, a widely accepted view has been that people are stuck with a basic setting on their happiness thermostat. It says the effects of good or bad life events like marriage, a raise, divorce, or disability will simply fade with time.
We adapt to them just as we stop noticing a bad odor from behind the living room couch after awhile, this theory says. So this adaptation would seem to doom any deliberate attempt to raise a person's basic happiness setting.
As two researchers put it in 1996: "It may be that trying to be happier is as futile as trying to be taller."
But recent long-term studies have revealed that the happiness thermostat is more malleable than the popular theory maintained, at least in its extreme form. "Set-point is not destiny," says psychologist Ed Diener of the University of Illinois.
One new study showing change in happiness levels followed thousands of Germans for 17 years. It found that about a quarter changed significantly over that time in their basic level of satisfaction with life. (That's a popular happiness measure; some studies sample how one feels through the day instead.) Nearly a tenth of the German participants changed by at least 3 points on a 10-point scale.
Other studies show an effect of specific life events, though of course the results are averages and can't predict what will happen to particular individuals. Results show long-lasting shadows associated with events like serious disability, divorce, widowhood, and getting laid off.
The boost from getting married, on the other hand, seems to dissipate after about two years, says psychologist Richard E. Lucas of Michigan State University.
What about the joys of having children? Parents recall those years with fondness, but studies show childrearing takes a toll on marital satisfaction, Harvard psychologist Daniel Gilbert writes in his recent book, "Stumbling on Happiness." Parents gain in satisfaction as their kids leave home, he said.
"Despite what we read in the popular press," he writes, "the only known symptom of 'empty nest syndrome' is increased smiling."
Gilbert says people are awful at predicting what will make them happy.
Yet, Lucas says, "most people are happy most of the time." That is, in a group of people who have reasonably good health and income, most will probably rate a 7.5 or so on a happiness scale of zero to 10, he says.
Still, many people want to be happier. What can they do? That's where research by Lyubomirsky, Seligman and others comes in.
The think-of-three-good-things exercise that Miller, the motivational speaker, found so simplistic at first is among those being tested by Seligman's group at the University of Pennsylvania.
People keep doing it on their own because it's immediately rewarding, said Seligman colleague Acacia Parks. It makes people focus more on good things that happen, which might otherwise be forgotten because of daily disappointments, she said.
Miller said the exercise made her notice more good things in her day. Now, she routinely lists 10 or 20 rather than three.