"It's in their genes" is a common refrain from scientists when asked about factors that allow centenarians to reach age 100 and beyond. Up until now, research has focused on genetic variations that offer a physiological advantage such as high levels of HDL ("good") cholesterol.

But researchers at Albert Einstein College of Medicine and Ferkauf Graduate School of Psychology of Yeshiva University have found that personality traits like being outgoing, optimistic, easygoing, and enjoying laughter as well as staying engaged in activities may also be part of the longevity genes mix.

The findings, published online in the journal Aging, come from Einstein's Longevity Genes Project, which includes over 500 Ashkenazi Jews over the age of 95 and 700 of their offspring. Ashkenazi (Eastern European) Jews were selected because they are genetically homogeneous, making it easier to spot genetic differences within the study population.

Previous studies have indicated that personality arises from underlying genetic mechanisms that may directly affect health. The present study of 243 of the centenarians (average age 97.6 years, 75 percent women) was aimed at detecting genetically-based personality characteristics by developing a brief measure (the Personality Outlook Profile Scale, or POPS) of personality in centenarians.

"When I started working with centenarians, I thought we'd find that they survived so long in part because they were mean and ornery," said Nir Barzilai, M.D., the Ingeborg and Ira Leon Rennert Chair of Aging Research, director of Einstein's Institute for Aging Research and co-corresponding author of the study.

"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."

In addition, the centenarians had lower scores for displaying neurotic personality and higher scores for being conscientious compared with a representative sample of the U.S. population.

"Some evidence indicates that personality can change between the ages of 70 and 100, so we don't know whether our centenarians have maintained their personality traits across their entire lifespans," continued Dr. Barzilai. "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."

The study is titled "Positive attitude towards life and emotional expression as personality phenotypes for centenarians."

The POPS was developed by lead author Kaori Kato, Psy.D., now at Weill Cornell Medical College, who validated it through comparisons with two previously established measures of personality traits. Other authors of the study were Richard Zweig, Ph.D., assistant clinical professor of psychiatry and behavioral sciences at Einstein and director of the Older Adult Program at Ferkauf, and Gil Atzmon, Ph.D., assistant professor of medicine and of genetics at Einstein.