Purpose – a powerful word.

However, I did not understand the full impact of this word until recently.

I have blogged before about Simon Sinek’s “Start with Why.” Focus on the end goal, or the “why,” is a commonality for successful and sustainable organizations. In addition, focusing on the end goals, rather than processes or rules to get there can make organizations antifragile – like Lincoln’s focus on reuniting the country as the template by which he put together a “Team of Rivals” for his cabinet. Despite being rivals, they were the most capable men to reunite the country.

In addition to inspiring action, inviting creativity, and embracing learning when approaching a series of problems, there is another critical role for purpose in our health.

As I previously wrote, our paradigm is that youth is health. By this paradigm, the comparison between biological age and chronological age determines health or disease.

The longitudinal study of longevity, called the Longevity Project, is an eight-decade project that followed a group of people from birth to death and asked what factors had the best prediction of longevity. This groundbreaking study has even more interest to those of us who are aging.

In the study, children and young adults who worried some actually lived longer than carefree children who took more risks. Prudent, dependable children had the best likelihood of longer life in the study.

In addition, conscientious people live longer and have more friends than people who shirk responsibility. The same for physically active, middle-aged adults – they lived longer than sedentary adults.

The strongest social predictor was a strong social network.

The best predictor as the subjects grew older? Maintaining a sense of purpose throughout life.

Start with why, maintain a sense of purpose, and live long.