Philosophers and other thinkers have been trying for thousands of years to get a grip on the elusive emotion of happiness, which arises with a rush of endorphins and can dissipate just as quickly.

Cassie Mogilner, a professor at The Wharton School, is one of those people who has been trying to tie down what makes people happy, in papers she's co-authored including "The Shifting Meaning of Happiness" and "The Pursuit of Happiness: Time, Money and Social Connection." Through years of academic research, Mogilner believes she has nailed down a the chief sources that elicit joy.

"I have found that focusing on time leads to greater happiness than focusing on money," she tells The Wharton School's blog Knowledge@Wharton in a video interview.

In one study, Mogilner asked people to fill out a survey while they were entering a café. The survey was a "sentence unscrambling task," which either focused on time-related words or money-related words. She then observed  the subjects while they were at the café talking, eating, or working. "As they left the café, we conducted another survey asking how happy they felt. Those who were led to think about time on their way into the café spent more time connecting and left happier than those who were led to think about money," she says.

For a second study, Mogilner scoured millions of blogs for sentences like "I feel" or "I am feeling happy," and then dissected the content. She found two forms of happiness--the feeling of being excited and the feeling of being calm. The study revealed that people in their teens and 20s were more likely to express excited happiness than calm happiness; people in their 30s were equally as likely to express one as the other; and people in their 40s, 50s, and 60s were more likely to express calm happiness than excited happiness. She concludes that "the way that we feel happy changes over the course of our life."

When it comes down to working on your own personal happiness levels, Mogilner says her research reveals the importance of changing focus. She suggests "to shift attention away from money, which is a resource that tends to absorb most of our attention and our thinking and planning on a daily basis, and shift attention to this fundamentally precious resource of time."  Making that shift "will remind you and motivate you to behave in ways that are happier, and to spend your time in more fulfilling ways."

An important thing to remember, she says, is to be self-aware and understand what makes you happy. If you love taking it easy on the weekends and binge-watching Netflix, then do it. If you find happiness making it rain in the club, well, make it rain already.

The most important thing to remember: "Even the way that you feel happiness will or has changed over the course of your life." If you're not a young buck anymore, do what makes you happy, instead of beating yourself up for watching Bogart kill it in The African Queen for the millionth time.

Published on: Nov 12, 2014