FRIDAY, June 5, 2015 (HealthDay News) -- How you smile or laugh may depend on your genes, a new study says.
Researchers tested 336 adults and found that those with short versions (alleles) of the 5-HTTLPR gene smiled or laughed more when looking at funny comics or amusing film clips, compared to those with long versions of the gene.
Previous research found a connection between the gene and negative emotions. This is the first time the gene has been linked to positive emotions, according to the authors of the study, which was published online June 1 in the journal Emotion.
The 5-HTTLPR gene is involved in regulating serotonin, a brain chemical implicated in depression and anxiety. This study adds to growing evidence that people with short versions of the gene may be more sensitive to emotional situations, 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," study author Claudia Haase, assistant professor in the human development and social policy program at Northwestern University, said in a university news release.
"Our study provides a more complete picture of the emotional life of people with the short allele. People with short alleles may flourish in a positive environment and suffer in a negative one, while people with long alleles are less sensitive to environmental conditions," Haase explained.
The study's senior author, Robert Levenson, said the results provide "a dollop of support for the idea that positive emotions are under the same tent as negative ones, when it comes to the short allele."
"It may be that across the whole palate of human emotions, these genes turn up the gain of the amplifier. It sheds new light on an important piece of the genetic puzzle," Levenson, a professor of psychology at the University of California, Berkeley, said in the news release.
More information
The American Academy of Family Physicians explains how emotions affect your health.
