People who are outgoing, optimistic, easygoing, and have a good sense of humor and a large social network are likely to live longer than others who don't possess these personality traits, according to new research.

The study reveals how saying "It’s in their genes" could refer to more than just genetic variations that give a physiological advantage like having high levels of HDL ("good") cholesterol because people with positive personality traits appear to live longer than those who do not.

The latest findings suggest that people who are born to be happy are also born to live longer.

Past research has found that personality, which arises from underlying genetic mechanisms, may play a direct role in affecting health, but up until now it was not clear whether individual temperaments also affected longevity. 

Researchers at Albert Einstein College of Medicine and Ferkauf Graduate School of Psychology of Yeshiva University found that people who are more likely to enjoy laughter and stay involved in activities may have "personality genes" that contribute to the longevity genes mix.

The study, published recently in the journal Aging, is based off of data from the Einstein's Longevity Genes Project, which includes over 500 Ashkenazi Jews over the age of 95 and 700 of their children.

Researchers selected people who were Ashkenazi or Eastern European Jews because they are genetically homogeneous, thus making it easier to identify genetic differences between study participants.

Researchers specifically looked at 243 of the centenarians with an average age 97.6 years to detect whether there were any genetically-based personality characteristics by using a Personality Outlook Profile Scale to measure these traits.

Study results showed that most of the centenarians studied had many qualities that were associated with having a positive attitude towards life, with most of the participants being outgoing, optimistic and easygoing.

"When I started working with centenarians, I thought we'd find that they survived so long in part because they were mean and ornery," co-researcher Dr. Nir Barzilai, director of Einstein's Institute for Aging Research, said in a statement.

"But when we assessed the personalities of these 243 centenarians, we found qualities that clearly reflect a positive attitude towards life. Most were outgoing, optimistic and easygoing. They considered laughter an important part of life and had a large social network. They expressed emotions openly rather than bottling them up," he added.

Furthermore, the centenarians studied scored lower for displaying neurotic traits and higher for being conscientious.

Researchers noted that personality can change in later life, and researchers were not sure whether participants had maintained the same positive characteristic traits during the course of their entire life.

"Nevertheless, our findings suggest that centenarians share particular personality traits and that genetically-based aspects of personality may play an important role in achieving both good health and exceptional longevity," Barzilai said.