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 happened that day and analyze why they occurred. That was supposed to increase her overall happiness. I thought it was too simple to be effective," said Miller. "I went to Harvard. I'm used to things being complicated." Miller was assigned the task as homework in a master's degree program. "The quality of my dreams has changed, I never have trouble falling asleep and I do feel happier." Miller said the exercise made her notice more good things in her day, and that now she routinely lists 10 or 20 of them rather than just three. 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. There has been very little research in how people become happier. The big reason ... is that many researchers have considered that quest to be futile. But recent long-term studies have revealed that the happiness thermostat is more malleable than the popular theory maintained. One new study ... followed thousands of Germans for 17 years. About a quarter changed significantly over that time in their basic level of satisfaction with life. Another approach under study now is having people work on savoring the pleasing things in their lives like a warm shower or a good breakfast. [Yet] another promising approach is having people write down what they want to be remembered for, to help them bring their daily activities in line with what's really important to them.

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