There might be more to your smile than you think. A study has shown that people who have a Duchenne smile live the longest. People with a Duchenne smile use their whole face with their eyes crinkled. There are also partial-Duchenne smiles and non-Duchenne smiles. A non-Duchenne smile may be indicating that you have negative emotions that may shorten your lifespan. Do you have a Duchenne smile? Take a selfie and compare it to the reference below. Take a new photo once a month to see how you have improved!