A genuine smile releases the tension in your jaws and face, then ripples that ease throughout your body. In the process, your mood is elevated and you feel more joyful.
Give it a try:
Break into a grin. Not just any grin. Try the kind that parts and bares your teeth, brings the corners of your mouth upward and crinkles your eyes.
Can’t seem to muster anything bigger than a smirk or a polite, mouth-closed, thin-lipped pseudo-smile? No problem. Fake it!
Place a pen (or your index finger) lengthwise between your teeth and far enough back into your mouth that it causes your lips to spread outward.
Can you feel the tension release?