Updated April 12, 2015.

The list of behavior changes that could enhance your longevity is long: eat well, lose weight, exercise more, do more puzzles to work your brain, drink green tea, consume more pomegranates. But deciding what to tackle first – which one behavior will make the most difference – can be daunting and confusing.

California psychologists and longevity researchers Howard Friedman and Leslie Martin think they have the answer.

As authors of The Longevity Project, they’ve studied more than eight decades’ worth of data on a group of 1,500 Californians, deciphering which personality traits and behaviors really affected their lifespan. The research was started in 1921 by Lewis Terman, a Stanford University psychologist.

The study's results debunk many popular notions about what actually helps you live longer. And when asked what one resolution would have the greatest impact on your longevity, Friedman suggests that you toss your ambitious list of behavior changes, and spend time with family and friends instead - a strategy that reduces stress and its negative impact on longevity.

"The Longevity Project discovered that it is responsible, goal-oriented citizens, well-integrated into their communities" who are most likely to have healthy and long lives, he says.

"Connecting with and helping others is more important than obsessing over one's diet, rigorous exercise program, or work load.", Friedman insists. "Do that and the other elements will fall into place."

Read more about Building Healthy Habits:

• Which habits make up a healthy lifestyle?
• Top 5 Habits for Healthy Aging
• Which Habits to Ditch

<sub>Source:

Friedman, H.S. and Martin, L.R. "The Longevity Project: Surprising Discoveries for Health and Long Life from the Landmark Eight-Decade Study." Penguin Books. March 2011. Personal correspondence with author Howard Friedman Dec.28, 2011.
More on "The Longevity Project".</sub>