A smile 'could add seven years to your life'

According to them, broader grins and wrinkles around the eyes reflect an underlying positive outlook on life that translates into better long-term health, British newspaper the 'Daily Mail' reported.

The researchers from Wayne State University, Michigan, have based their conclusions on an analysis of old photographs of major league baseball players printed in the 1952 Baseball Register which listed each player's statistics such as date of birth, weight, marital status and career details.

The researchers ranked each player according to whether they had no smile at all, a partial smile, where only the muscles around the mouth were involved, or a full-blown smile that featured a toothy grin, raised cheeks and creases around the eyes.
They then compared the photos with the life span of each player. The results revealed that of the 184 players that had since died, those in the "no smile" category had lived an average of 72.9 years.

Among the "partial smiles" group, lifespan had averaged out at 75. But those with the biggest grins had lived for an average of 79.9 years -- seven more than their straight -faced colleagues, the study found.
The study also found that putting on a false grin may not give the same benefit as the extra life expectancy was only seen in players who had genuine smiles, known as Duchenne smiles.

These are smiles that engage groups of muscles around the mouth and eyes and are named after the 19th-century neurologist who defined them in detail. 'Non-Duchenne' smiles affect only the mouth.
The findings have been published in the 'Psychological Science' journal. P