Health News

A baby’s smile is not related to emotion

Babies smile before they are born. That same sweet smile is the smile babies do in the first few weeks of life. It is called a reflexive smile. These smiles are random and spontaneous. They usually occur while a baby is sleeping.

Scientists believe the motor cells activated by neurons in the brain stem are why babies smile while sleeping. The smile is not because a baby is passing gas or in a good mood. It is because their brain is active while they are sleeping.

This early smile is also called a fake smile. It is a smile not related to emotion, but related to a trigger in the brain.

A genuine smile, a smile related to emotions originates in a different part of the brain, the limbic system. As a baby nears the age of 6 to 8 weeks the baby’s limbic system coordinates with the facial muscles to produce what is called a genuine smile, a smile that says “I care about you.” The limbic system (the brain’s emotional center) activates the eye muscles called the orbicularis oculi (the muscles near our eyes), and the zygomatic major muscle in our cheeks. This muscle then brings our lips upward, creating the smile. This all happens quickly, from 1 to 4 seconds.

The genuine or social smile of a baby appears around the same time in all babies, in all cultures. Even babies who are blind start this type of smile when they hear the voices or fell the touch of someone who loves them.

Smiles are powerful. Smiles are addicting. Smiles are contagious. Smiles are building blocks for attachment.

One of the most famous people who studied and wrote about smiling is the French anatomist Guillaume Duchenne. He wrote “the zygomatic major can be willed into action, but only the sweet emotions of the soul force the orbicularis oculi to contract.” He wrote, when the eye muscles are not engaged in smiling, the smile “unmasks a false friend.” To this day a true genuine smile is referred to as a Duchenne smile.

When a baby smiles at their parent, the parent’s brain reacts with a flurry of activity. The substantia nigra, the striatum and the emotional networks in the frontal lobes release the neurotransmitter dopamine. Dopamine raises our mood, makes us feel good. It can make us feel so good we want more of it. Once a baby starts smiling a parent will play with their baby to get that smile over and over again. The game of making a baby smile helps the baby’s brain develop. Smiling games are good for both the parent and the baby.

Smiles are definitely contagious. When someone smiles at you, you automatically smile back without realizing you are doing so. If you are in a truly grumpy state of mind that might not happen, but generally speaking smiles create smiles.

Smiles are unique as well. We have special smiles for special people in our lives.

Darwin in his book “The Expression of Emotions in Man and Animals,” written in 1872, theorized that smiling is a universal expression. Smiling goes across all cultures as a way of expressing joy, tenderness and love.

Writing this column has made me smile. I hope you smiled when you were reading it.

Smile and the world will smile with you. Happy smiles to you!