Easy Smiles May Be Genetic

Jun 10, 2015, by Dr. Becky Coats

Researchers at Northwestern University think they may have found the secret to why some people are very emotional, smiling and laughing or breaking down and crying, while others are more stoic.

The secret, they say, is in the DNA.

Variations on a Gene

Genetic SmilesResearchers have focused in on a particular gene, 5-HTTLPR, which has two variations or alleles. The gene is involved in the regulation of serotonin levels, and one variation is short and the other is long. People inherit versions from both parents, and it’s possible to have one short and one long. To determine the effect of this variation, researchers used three tests involving a total of 336 subjects.

First, they showed subjects “The Far Side” cartoons by Gary Larson and a selection of cartoons from The New Yorker. Second, they showed a short clip from the film “Strangers in Paradise.” In the final experiment, they asked people to talk with their spouse about a disagreement in their marriage.

The experiments were designed to elicit subtle emotions so that only people who were especially prone to expression would be triggered into laughing or becoming sad. Scientists recorded people’s responses during the experiment. As they watched the people’s responses, trained researchers then rated people’s smiling, laughter, and sadness using the “Facial Action Coding System,” which is so intriguing we may have to explore it further in the future. Anyway, this coding system looks at subtle facial movements associated with emotion, and it enabled researchers to determine who was responding to the stimuli and who wasn’t.

Subjects were then tested for variations on the gene.

It was determined that people who had the shorter allele were more likely to display genuine amusement at both the clip and cartoons.

This research follows other research that has shown this allele is associated with a greater risk for depression. One of the researchers said, “Having the short allele is not bad or risky. Instead, the short allele amplifies emotional reactions to both good and bad environments.”

Genetics Is Not Destiny

However, researchers in this study also added, “The fundamental truth of genes is that they don’t have the final say.” People with the short allele respond more strongly to conditioning and their environment, but their environment still matters.

One part of your conditioning is how people respond to your smile. If you have a smile that leads to other people smiling, you will smile more often, but if your smile causes negative responses because of unattractive or unhealthy teeth, you are more likely to become depressed yourself.

Cosmetic dentistry helps ensure you have a smile that looks good and gets positive feedback every time you share it. No matter what the problems with your smile, we can help.

To learn how we can help you get a smile you’ll be happy to share, whether you share it often or rarely, please call (817) 481-6888 for an appointment with a Grapevine cosmetic dentist at Grapevine Dental Care today.