Do those who laugh the most live the longest?

Possibly so, according to a new study in the journal Aging.

Researchers from Albert Einstein College of Medicine and Yeshiva University found that people who possess certain personality traits based in genetics may live longer lives -- particularly those who are optimistic, laugh a lot and are easygoing.

The study was based on an analysis of 243 people with an average age of 97.6. These people were part of a bigger study, called the Longevity Genes Project at Albert Einstein College of Medicine, which examines 500 Ashkenazi Jews ages 95 and older (Ashkenazi Jews are genetically homogenous, researchers said), as well as 700 of their offspring.

"When I started working with centenarians, I thought we'd find that they survived so long in part because they were mean and ornery," study researcher Dr. Nir Barzilai, M.D., 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," he said. "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."

The researchers also found that the study participants scored lower on tests for neurotic personality and scored higher on tests for conscientiousness, compared with comparable scores for the U.S. population.

Last year, a study in the journal Proceedings of the National Academy of Sciences showed that older people who are happy have a 35 percent lower risk of dying over a five-year period than unhappy people. That study included 3,853 people ages 52 to 79.

"The happiness could be a marker of some other aspect of people's lives which is particularly important for health," study researcher Andrew Steptoe, a professor at University College, London, told The Telegraph. "For example, happiness is quite strongly linked to good social relationships, and maybe it is things like that that are accounting for the link between happiness and health."

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