Smile your way to a long life

LOS ANGELES — People who smile a lot are usually happier, have more stable personalities, more stable marriages, better cognitive skills and better interpersonal skills, according to research. Science has just uncovered another benefit of a happy face. People who have big smiles live longer.

Researchers at Wayne State University used information from the Baseball Register to look at photos of 230 players who debuted in professional baseball before 1950. The players' photos were enlarged and a rating of their smile intensity was made (big smile, no smile, partial smile). The players' smile ratings were compared with data from deaths that occurred 2006 and 2009. The researchers then corrected their analysis to account for other factors associated with longevity, such as body mass index, career length, career precocity and college attendance.

For those players who had died, the researchers found longevity ranged from an average of 72.9 years for players with no smiles (63 players), to 75 years for players with partial smiles (64 players) to 79.9 years for players with big smiles (23 players).

This isn't a bunch of psycho-hooey, the authors said. Smiles reflect positive emotion. Positive emotion has been linked to both physical and mental well-being. They added a caveat to their study, noting: "The data source provided no information as to whether expressions were spontaneous or in response to a photographer's request to smile." Still, big smiles are more likely to reflect true happiness than partial smiles.

What I'm wondering is, did they account for each team's winning records? Maybe the non-smilers were thinking about batting averages.

The study is published in the journal Psychological Science.