Millions of Americans are making New Year’s resolutions. Some will vow to make more money or new friends. Others will focus on exercising more or eating less. Each resolution represents the hope that changing one’s behavior or priorities will bring increased happiness.

Such aspirations are a truly American tradition. Here, the pursuit of happiness is a substitute for fixed estates or castes, promising that every person can establish personal priorities rather than filling a role dictated by birth or tradition. It’s even built in our founding documents: In the Declaration of Independence, Thomas Jefferson placed the “pursuit of happiness” next to life and liberty.

And yet, most Americans are left with more pursuit than actual happiness. The Harris Poll’s Survey of American Happiness, conducted annually since 2008, has consistently shown that only about a third of Americans feel happy.

So what New Year’s resolution should we make to achieve happiness? The philosopher and psychologist William James had some ideas. At the turn of the 20th century, James explored how to find happiness, and his lessons can help us balance the desire for material satisfaction and social status with the more substantial goal of personal fulfillment.

In a chapter from his 1890 book, “The Principles of Psychology,” James summarized the search for happiness with a simple equation: Self-esteem = Success/Pretensions. Success can make us happy by boosting our self-esteem. But high expectations can undercut that happiness. It is not enough simply to succeed more; we also have to adjust our expectations.

James distinguished between happiness and satisfaction. Compared to happiness, satisfaction depends more on external circumstances and so is more easily eroded by high expectations: For example, we may overestimate the power of a glitzy new cellphone or a promotion at work to finally bring permanent smiles.

Americans have long been known for their love of newfangled devices, as British journalist Henry Norman observed during an 1898 visit to the United States. Unlike the British, with their persistent loyalty to things that work, Americans celebrate (and buy) countless new possessions, even when they don’t address any particular need. What’s more, Norman observed, Americans “will try an object one day and throw it away the next for something a trifle more convenient or expeditious.”

Happiness, for James, was different. It generally marches to the beat of its own drummer, without waiting for outside support. Henry David Thoreau, for instance, lowered his expectations by living simply at Walden Pond. With fewer material satisfactions, he declared that “my wealth is not possession but enjoyment” — an idea that included relishing experiences and simply having more time.

And yet the paths to happiness advocated by Thoreau and James have remained unpopular. Americans have largely opted to pursue satisfaction, not happiness, seeking material gain and social successes to stoke their self-esteem. For decades, these pursuits have been engines for economic growth and staples of American politics. In 1941, President Franklin Roosevelt enshrined the “freedom from want” as a pillar of democracy, on par with First Amendment freedoms.

James recognized something fundamentally important, something that’s become lost in our ever-expanding consumer culture: Material satisfaction fulfills basic needs, but once a person is freed from desperation, more material goods can actually undercut happiness, especially if the expectations for satisfaction keeps rising.

As a result, the constant search for satisfaction can put happiness permanently out of reach, because even the success wrought from high achievements will always feel “ever not quite,” as James realized. Hollywood’s classic 1941 film “Citizen Kane” captured this dynamic. Orson Welles’ character, Charles Foster Kane, was awash in wealth but constantly pined for the simple joys of childhood, symbolized by Rosebud the sled.

James himself only gradually came to this realization. As a young man, he was unhappy, despite growing up in a well-off family and enjoying the privilege of a Harvard education. When researching his early development, I was struck by his physical ailments, depression, uncertainty about his career, family tensions and awkwardness with women. He even vowed never to marry to avoid any chance of passing his troubled traits to another generation.

Despite his problems, James became the founder of American psychology, an advocate for pragmatism, an innovator of spiritual approaches to religion and a committed public intellectual. How did this disturbed young man become such a confident and influential figure?

He ditched satisfaction in favor of happiness.

James embraced his limitations, rather than focusing all his attention on fixing them. In letters to family and friends, he even called his problems “a periodical neccessity (sic).” This new posture gave “a sort of deep enthusiastic bliss.” Happiness, he understood, emerged from a “bitter willingness to do and suffer anything.” The meaningful future he was creating, even in small steps of learning, writing and discussing, was more important than his troubles. And those purposeful engagements became his new source of contentment.

In his 1892 book “Psychology,” James drew on this distinction between satisfaction and happiness. The self in its material and social dimensions craves things and status for satisfaction. Beneath our material and social selves, however, an inner core persists with purpose, no matter what satisfactions the world brings or withholds. If financial or social successes, or any other short-term want, are not in tune with that self, better to find different goals.

James’ insights have shaped the contemporary field of positive psychology. Researchers today advise seeking happiness in two ways. First, pay attention to your own distinct traits and cultivate those as your strengths. Second, because initial strengths are often not enough, persist with motivation and commitment. This “grit” is generally a surer path to success than native ability.

For the contemporary psychologists, as for James, the greatest happiness comes from finding meaning through focus on significant purpose. Satisfying countless material wants cannot measure up to the happiness flowing from creative achievement or from helping a child in need.

And often, with the focus on well-chosen inner purpose, material and social successes will emerge as side effects of being true to one’s self.

So go ahead, make those New Year’s resolutions. Incorporating these suggestions from James and company can turn your vow into a path to happiness:

1. Make a resolution that’s in tune with your deepest commitments.

2. Invest in that resolution with a sense of purpose.

3. Don’t shy away from the challenges it might present. Keep going.

Paul J. Croce is professor of history at Stetson University and author, most recently, of “Young William James Thinking.” He wrote this article for the Washington Post.