The late celebrated author Gabriel Garcí­a Márquez once wrote: "Age isn't how old you are but how old you feel." Turns out there's some science behind that belief, with a new study reporting that people who feel younger than their actual age have a lower death rate.

"Self-perceived age reflects appraisals of health, physical limitations, and well-being in later life," the authors of the study from University College London wrote. "Older people typically feel younger than their chronological age, and it is thought that those who feel younger than their actual age have reduced mortality."

The study tracked 6,489 individuals with an average age of 65.8 years, but a self-perceived age of around 56 years. A large majority of the group (nearly 70 percent) reported feeling three years younger or more, while 25.6 percent felt closer to their real age and 4.8 percent felt more than a year older than their chronological age.

A little over eight years later, the researchers checked in with the group and discovered something interesting: those who felt younger experienced a much lower death rate than the rest of the group. According to the study, the mortality rate was 14.3 percent in adults who felt younger, 18.5 percent for those who felt about their actual age and 24.6 percent in those adults who felt older.

The authors theorized that those who feel younger likely have healthier lifestyles, greater optimism, and a willingness to engage with those younger than their age. They also gave hope to those feeling older, adding that with targeted positive messages, they too can benefit from a change in attitude for better health and longevity.

"Optimism pays off," James Maddux, professor emeritus of psychology and senior scholar at the Center for the Advancement of Well-Being at George Mason University, in Fairfax, Virginia, told HealthDay. "Even though there probably is a large genetic component to whether you are optimistic or pessimistic, we also know from research that optimism can be learned," he said. "It's a trait that's worth picking up."

The older we get, the younger we feel

As we age, most people tend to yearn for the past and that mentality can actually help people feel younger than their actual age, according to one study. Researchers discovered that 70 percent of people begin to feel younger around age 30 and that feeling grows as they age.

"It keeps going up with us, and at just a slightly slower rate than how we feel right now," the study's co-author Brian Nosek told BBC News. Subjective aging “support(s) the idea that we experience our life experiences as continuously getting better, just a bit more slowly than our actual experiences.”

Reflecting on fond memories from your younger years may in fact make you feel closer to that age than your actual age. You may feel compelled to be more active, more optimistic and that in turn can help you live a longer, more vibrant life.

Editor's note: This article has been updated since it was originally published in December 2014.

Michael d'Estries ( @michaeldestries ) covers science, technology, art, and the beautiful, unusual corners of our incredible world.

Believing 'age is just a number' can help you live longer
Several studies explore how positive personal perception can manifest itself in a lower mortality rate.