Forget about money. Don't fret about youth. Acting happy is likely to make you happy.

There are happy people. Researchers at the National Institute on Aging found that well-being is strongly influenced by enduring characteristics of the individual. In a 10-year study, they found that, regardless of whether their marital status, job, or residence had changed, people with a happy disposition in 1973 were still happy in 1983. There's good news in these findings: Given the right disposition, in the face of difficulty, people can still find renewed happiness.

What makes for a happy disposition? Who are these people who stay basically up despite life's downs? There are four important traits of happy people:

I: Self-esteem: Happy People Like Themselves

During the 1980s, no topic in psychology was more researched than the self. Many reports showed the dividends of high self-esteem--in some University of Michigan studies of well-being in America, the best predictor of general life satisfaction was not satisfaction with family life, friendships, or income, but satisfaction with self. People who like and accept themselves feel good about life in general.

This will come as no surprise to anyone attuned to the pop psychology of our age. Self-help books exhort us to respect ourselves, to dwell on our good points, to be positive. Cut the self-pity. Stop the negative talk. To discover love, first love yourself. We've heard the message: In a 1989 Gallup poll, 85 percent of Americans rated "having a good self-image or self-respect" as very important; 0 percent rated it unimportant.

Actually, most of us have a good reputation with ourselves. In studies of self-esteem, even low-scoring people respond in the mid-range of scores. (A "low" self-esteem person responds to statements such as "I have good ideas" with a qualifying adjective such as "somewhat" or "sometimes.")

Moreover, one of the most provocative yet firmly established conclusions of social psychology concerns the potency of "self-serving bias." People accept more responsibility for good deeds than for bad, for successes than for failures. The question "What have I done to deserve this?" is one we ask of our troubles, not our successes--those we assume we deserve.

On nearly any subjective or socially desirable dimension, most people actually see themselves as better than average. We also remember and justify our past actions in self-enhancing ways, are quicker to believe more flattering descriptions of ourselves than unflattering ones, and overestimate the extent to which others support our opinions and share our foibles. For most of us, these "positive illusions" protect against anxiety and depression. All of us at some time do feel inferior--especially when comparing ourselves with those who are a step or two higher on the ladder of status, looks, or income. The deeper and more frequently we have such feelings, the more unhappy we are. Therefore, we function better with modest self-enhancing illusions.

A healthy self-esteem, then, is both positive and realistic. Because it is based on the genuine achievement of realistic ideals, and on feeling accepted for what one is, such self-esteem provides a strong foundation for enduring joy.

II: Optimism: Happy People Are Hope-Filled

Those who agree that "with enough faith, you can do almost anything" and that "when I undertake something new, I expect to succeed" may be a bit bubble-headed. But, for seeing the glass of life as half-full rather than half-empty, they are usually happier.

Optimists are also healthier. Several studies reveal that a pessimistic style of explaining bad events--saying, "It's my fault, it's going to last, and it's going to undermine everything"--makes us more vulnerable to illness. Harvard graduates who were most pessimistic when interviewed in 1946 were least healthy when restudied in 1980. Virginia Tech students who reacted to bad events pessimistically suffered more colds, sore throats, and flu a year later. In general, optimistic people are less bothered by various illnesses and recover better from cancer and surgery.

Optimists also enjoy greater success. Rather than see setbacks as signs of their incompetence, they view them as flukes or as suggesting the need for a new approach. A person who confronts life with an attitude that often says "Yes!" to people and possibilities lives with far more joy and venturesomeness than do habitual naysayers.

Yet in affirming the great truth about optimism, let us also remember a complementary truth about the perils of unrealism. Unrealistic optimists may fail to take sensible precautions. And consider the shame and dejection that accompanies shattered expectations. If you believe the inspirational messages of positive thinkers, then whose fault is it if you don't march upward from highs to higher highs? What do we conclude when our marriages turn out to be less than we romanticized, when we are less successful than we dreamed?

At such times, we have only ourselves to blame. When the dream collapses, the biggest dreamers often fall the hardest. Limitless optimism breeds endless frustrations.

The recipe for well-being, then, requires neither positive nor negative thinking alone, but a mix of ample optimism to provide hope, a dash of pessimism to prevent complacency, and enough realism to discriminate those things we can control from those we cannot.

III: Extroversion: Happy People Are Outgoing

In study after study, extroverts--social, outgoing people--report greater happiness and satisfaction with life. The explanation seems partly temperamental. "Extroverts are simply more cheerful and high-spirited," report National Institute of Aging researchers Paul Costa and Robert McCrae. Self-assured people who walk into a room full of strangers and warmly introduce themselves may also be more accepting of themselves. Liking themselves, they are confident that others will like them, too.

Such attitudes tend also to be self-fulfilling, leading extroverts to experience more positive events. When University of Illinois researchers Ed Diener and Keith Magnus studied students at the undergraduate level and then again four years later as alumni, they found that life had treated extroverts more kindly. Compared to introverts, extroverts were more likely to have gotten married, found good jobs, and made new, close friends.

Extroverted people are more involved with others. They have a larger circle of friends and they more often engage in rewarding social activities. They experience more affection and enjoy greater social support--an important wellspring of well-being.

IV: Personal Control: Happy People
Believe They Choose Their Destinies

Summarizing the University of Michigan's nationwide surveys, researcher Angus Campbell commented that "having a strong sense of controlling one's life is a more dependable predictor of positive feelings of well-being than any of the objective conditions of life we have considered." And the 15 percent of Americans who feel in control of their lives and feel satisfied with themselves have "extraordinarily positive feelings of happiness."

Consider your own sense of personal control. Would you agree with the statement that "I don't have enough control over the direction my life is taking" or that "What happens to me is my own doing"? That "The world is run by a few powerful people" or that "The average person can influence government decisions"? Those whose responses to such statements reveal an "internal locus of control" typically achieve more in school, cope better with stress, and live more happily.

Increasing people's control can noticeably improve their health and morale as well. One study by Yale psychologist Judith Rodin encouraged nursing-home patients to exert more control--to make choices about their environment and to influence policy. As a result, 93 percent became more alert, active, and happy. Similar results have been observed after allowing prisoners to move chairs and control the lights and TV, and after enabling workers to participate in decision making.

Happy, too, are those who gain the sense of control that comes with effective management of one's time. Unoccupied time, especially for out-of-work people who aren't able to plan and fill their time, is unsatisfying. Sleeping late, hanging out, and watching TV leave an empty feeling. For happy people, time is "filled and planned; they are punctual and efficient," says Oxford University psychologist Michael Argyle. "For unhappy people, time is unfilled, open, and uncommitted; they postpone things and are inefficient."

Establishing pre-set deadlines for oneself--and then meeting them--can lead to the delicious, confident feeling of personal control.

Finally: How To Be Happy

It's easily enough said that happiness comes with having positive self-esteem, feeling in control of our lives, and having optimistic, outgoing dispositions, but how can we strengthen such traits? If we wish we were happier, can we somehow become more positive, inner-directed, confident, and extroverted? Just how malleable are we?

Well-meaning advice to "be more outgoing" or to "have a more cheerful outlook" can burden us with the responsibility to choose our basic temperament. More than such advice-givers realize, we bring our basic dispositions with us into the world.

More and more studies show that our basic personality traits endure, especially after childhood. While developmental psychologists are sometimes surprised by how often troubled, unhappy children mature into competent, successful adults, there is nonetheless an underlying consistency to personality. After the end of the teen years, traits such as outgoingness, emotional stability, openness, agreeableness, and conscientiousness seem to persist throughout adulthood.

But it's also true that we have the power to affect our own destinies, for we are the creators as well as the creatures of our social worlds. We may be the products of our past, but we are also the architects of our future. Personality isn't programmed like eye color. The predispositions we bring with us into the world leave room for nurture's influence, and our own efforts as well. What we do today shapes our world and ourselves tomorrow.

If social psychologists have proven anything during the last 30 years, they have proven that the actions we take leave a residue inside us. Every time we act, we amplify the underlying idea or tendency behind it. Most people presume the reverse: that our traits and attitudes affect our behavior. While this is true to a certain extent (though less so than commonly supposed), it is also true that our traits and attitudes follow our behavior. We are as likely to act ourselves into a new way of thinking as to think ourselves into a new way of acting.

There is a practical moral here for us all. Do we wish to change ourselves in some important way? Perhaps boost our self-esteem? Become more optimistic and socially assertive? Well, a potent strategy is to get up and start doing that very thing. Don't worry that you don't feel like it. Fake it. Pretend self-esteem. Feign optimism. Simulate outgoingness.

In experiments, people have been asked to write essays or present themselves to an interviewer in either self-enhancing or selfdeprecating ways. Those who act as if they are exceptionally intelligent, caring, and sensitive people later express higher self-esteem when privately describing themselves to a different researcher. This saying-becomes-believing effect is harnessed by therapy techniques (such as behavior therapy, rational-emotive therapy, and cognitive therapy), each of which prods the clients into practicing more positive talk and behavior.

Yes, telling people to act or talk positively sounds like telling people to be phony. But, as usually happens when we step into some new role--perhaps our first days "playing" parent, salesperson, or teacher--an amazing thing happens: The phoniness gradually subsides. We notice that our uncomfortable sense of being a parent, for instance, no longer feels forced. The new role--and the new behaviors and accompanying attitudes--have begun to fit us as comfortably as an old pair of blue jeans.

The moral: Going through the motions can trigger the emotions. Surely you've noticed. You're in a testy mood, but when the phone rings you feign cheer while talking to a friend. Strangely, after hanging up, you no longer feel so grumpy. Such is the value of social occasions--they impel us to behave as if we were happy, which in fact helps free us from our unhappiness.

Granted, we can't expect ourselves to become more upbeat and socially confident overnight. But rather than limply resign ourselves to our current traits and emotions, we can stretch ourselves, step by step. Rather than waiting until we feel like making those calls or reaching out to that person, we can begin. If we are too anxious, modest, or indifferent, we can pretend, trusting that before long the pretense will diminish as our actions ignite a spark inside--the spark that will lead to happiness.