In the United States, the pursuit of happiness is more than an inalienable right -- it's a national obsession. This accounts for the excess of books, blogs and motivational speakers that preach the gospel of personal contentment. But how can we the laypeople parse the wisdom from the dreck? We checked with the latest scientific studies, plus we consulted a bona-fide happiness expert. Angus MacDonald III is a professor of psychology at the University of Minnesota, where he teaches the occasional course on the science of happiness. The key to understanding this subject, he said, lies in the human capacity for adaptation to change.

STEP ONE: MIND YOUR 'SET POINT'

"There's a fair amount of data showing that the 'happiness set point' -- the level of contentment one feels with one's life -- is to a great extent influenced by genes," started MacDonald. The University of Minnesota's legendary studies of twins from the 1980s demonstrated this point: Researchers recorded similar levels of happiness in identical twins who had been separated at birth.

Illustrating the concept of the set point, MacDonald compared a person's capacity for happiness with his sense of sight. "If you walk into a really bright room you're not dazzled forever. You're dazzled for a few moments," explained MacDonald. "Your eyes will adapt pretty quickly." Likewise, when something positive happens in our lives -- winning the lottery, relocating to a warmer climate -- we receive only a temporary bump. "For the most part, people return to their previous level of happiness," said MacDonald.

STEP TWO: PRACTICE GRATITUDE

But there's good news, continued MacDonald -- a person can manipulate her set point, but not without consistent effort and hard work. (Scientists have compared cultivating happiness with maintaining one's ideal body weight -- it's easier for some than others.) MacDonald suggested the rigors of a Buddhist meditation practice for serious happiness-seekers, since a number of studies have demonstrated the benefits of fostering gratitude in one's life. Or try setting aside some time each week to express your appreciation, perhaps by composing a list of everything you're thankful for. "If you are grateful for something, that ties in back with the idea of adaptation," explained MacDonald. "[Gratitude] may actually slow the process of adapting to a new good thing."

STEP THREE: NURTURE RELATIONSHIPS

Here the evidence is weaker, said MacDonald, but there's some science to support the boost people get from cultivating a circle of positive, loving companions. "If you obtain pleasure from the things a person says, or from the compliments someone gives you -- those are the kinds of things you won't adapt to," argued MacDonald. Research hints that strong, healthy relationships are more emotionally fulfilling than either money or career. It's true that married people and church-goers are, on average, happier than the rest of us. But that shouldn't prevent singles and atheists from trying to boost their set point. A recent British study found that people over 50, especially women, are happiest when they have regular interactions with a wide circle of caring friends.

STEP FOUR: ENOUGH WITH THE STUFF!

Here's a well-known saw of the happiness gurus: Happy people devote their resources to experiences -- communal meals, vacationing with friends -- rather than fancy cars or bigger houses. MacDonald sees some scientific evidence to support this thinking: "There's a difference between liking and wanting," he explained. "It is sometimes the case that you like what you want. It's frequently the case that what you want are the kinds of things you adapt to quite readily." MacDonald cites the stuffed animals his children repeatedly long for, then quickly abandon to the outer reaches of the bedroom floor. And besides, wanting and liking are associated with completely different neurochemicals and brain areas, added MacDonald. What's the takeaway? Don't bother buying or longing for every little thing you desire. Content yourself with enjoying the people, places and things you encounter everyday.

STEP FIVE: GIVE IT AWAY

"There's been some interesting new research on charity," added MacDonald, citing three fresh studies which replicate the same finding: "People who give back feel better in the short-term," he said. Here's an important caveat for those on a fixed income: It's not the amount of money that matters; it's how you spend it. These studies, published in 2008, recorded spikes of happiness when subjects bought small gifts for family, trivial treats for friends or made modest donations to their favorite charities.

Christy DeSmith • 612-673-1754