The wider you grin, and the deeper your laughter lines, the more likely you are to live a long life. At least that's what researchers at Wayne University in Michigan say. In a study examining pictures of 1952 major league baseball players, researchers found that those with the widest grins lived an average of 79.9 years- a full seven more years than their glum colleagues! The study also found that false smiles don't count- only those who looked genuinely happy had longer expectancies.