eye muscles involved in smiling, the lower lateral orbicularis Oculi
pars palpabraeus, which crinkle up our lower eyelids and produce crow's
feet, seem solidly connected with lighthearted, open-hearted good
feelings and warmth.
The eye smile muscles can work with the levator
labii superioris-- upper toothy smile muscles-- to intensify the total
smile. These lift the upper lip to show the teeth, and are connected to
the orbicularis oculi pars palpabraeous eye smile muscles. Try making a
little smile, then add your heart and turn the smile into a strong,
genuine, high intensity smile, including your eyes.
Darwin suggested that the levator muscles might be involved and that at the least, they were attached to the orbicularis oculi muscles and they either aided in the lifting of the upper lip when the oculi muscles were involved or at least, acted as cables, pulling up the upper lip through the activation of the eye smile muscles. Paul Fair, when a graduate student at Harvard, found that the lower outer portion is the only part of the ring of muscle encircling the eye that is significantly involved in smiling. I instruct clients to practice smiling with just the lower outer part of their orbicularis oculi, to be careful that they don't frown or just squeeze the entire eye muscle when they attempt to activate the key part of the muscle.
Ekman reports that not everyone appears to be able to voluntarily control the lower orbicularis oculi muscle. His observation concurs with our own findings. Yet we've seen that with biofeedback aided training people can usually learn to develop voluntary control of these muscles. It may be that learning to turn on smiling eyes is like learning to warm the hands. You can get good at the skill without being able to verbalize what you are doing.
It seems that smiling with the eyes makes it easier to connect with, and smile with and from the heart. The eye smile muscles become involved in more intense, intimate and open smiling. Barriers seem to melt when two people face each other eye to eye and smile a full faced smile with puffed lower eyelids and gleaming, squinted eyes. Darwin speculated squeezing the eyeball caused a change in its shape which produced the sparkle so often associated with smiling, cheerful eyes.
There may be some muscle activity involved. besides the zygomaticus in raising the upper lip. The levator superioris muscle is definitely involved in the look of disdain, and may be involved in lifting the upper lip in some strong smiles. Ducchenne actually separately categorized the zygomaticus into two parts, one to raise the corners of the mouth and the other raising the upper lip. But many facial anatomy charts omit the zygomaticus minor.
Some people, particularly people who wore braces, are shy about showing their upper teeth. They inhibit or minimize the activity of the muscles that raise the upper lip. Experiment with adding lifting your upper lip to your smile. Pay attention to the different parts of your upper lip and how your feelings vary as you activate them.
Showing the upper teeth in a smile appears to always be accompanied by zygomaticus activity. But what happens if a person is shy or nervous and inhibits the major ingredient in his or her smile. If he inhibits the zygomatic ''primary'' smile activity but allows the ''secondary smile activity'' upper lip to be raised, or pulls his lips straight back rather than up towards the zygomatic arch, he may turn on a "nerdy" kind of grin like the Nerds in the Nerds movies, "Seymour" in The Little Shop of Horrors or Jerry Lewis in his earlier comedies. Or the zygomatic activity may be replaced with a pursed lipped, forced smile produced by the buccinator and risorius or platysma.
Emotional Expression Anatomy