smile with the lips separated, as wide as possible. Hold the smile for about 5 to 10 seconds. Relax and repeat. Aim for 15 to 30 reps. Smiling can help to strengthen the muscles in the face.

But there are several reasons to make the effort to smile, even when you don’t feel like it. Psychology research in several areas has revealed that the act of smiling itself can have benefits.

Tugging on the forehead, eyebrows, lips and cheeks ... “I think it’s because I smile a lot,” she says, smiling. The French anatomist Duchenne published landmark studies of human facial ...

All smiling involves contraction of the zygomatic major muscles, which lifts the corners of the mouth. But a Duchenne smile is characterised by the additional contraction of the orbicularis oculi ...

“Dogs don’t do this true smiling behavior to other dogs.” Dogs smile by pulling one or both lips back and may show all or some teeth. This smiling is accompanied by other greeting ...