Are you quick to release a giant guffaw when something funny happens? Or more likely to give a quick reserved smile? New research published today in the American Psychological Journal Emotion indicates that your reaction to something funny may be due to a variant in gene 5-HTTLPR. Gene 5-HTTLPR is involved in regulating serotonin, a neurotransmitter involved in depression or anxiety.
Scientists from Northwestern University and the University of Geneva co-authored the study, which took place in labs at the University of California, Berkeley. The researchers were focusing on the length of the alleles of gene 5-HTTLPR, which had previously been linked to negative emotions. Alleles are variations of genes. Each of your gene has 2 alleles, one inherited from your mother and one from your father.
The research indicated that people with the shorter alleles of the gene smiled and laughed more while watching humorous cartoons or funny film clips than people with longer versions of the allele. Having one type of the allele does not mean negative consequences or risks to the health of the person, it simply means that they may be more sensitive to emotional highs and lows. Researchers are quick to note that there are a variety of factors that influence our behavior, so this is not to say your genes are completely in control when it comes to your emotions.
To complete the study, researchers completed three experiments. In the first, young adults were shown cartoons from the New Yorker and Gary Larson's Far Side. The second experiment involved young, middle-aged and older adults watching a slightly amusing clip from the movie "Strangers in Paradise". Lastly, the third experiment required middle-aged and older spouses to discuss something they've disagreed on in their marriage. Each experiment was filmed and researchers analyzed and coded smiles and laughter using the Facial Action Coding System. This system helps to discern a genuine smile or laugh from one that may be forced to be polite or fit in to a social situation. After analyzing the DNA of each of the participants and comparing each individual's gene 5-HTTLPR, they found that those with the short allele showed more genuine smiling and laughing than those with the long allele.
This is a great example of how genetics, nature, nurture and life experiences can all come together to make us who we are. Studying genetics can be a lot of fun at any level of education! Check out some of the links in the resources section below for some genetics activity ideas to use at school or home.
- Science Daily: "Quick to laugh or smile? It might be in your genes"
- Daily Mail UK: "Get the giggles easily? Blame your genes: Genetic variant enhances how people react to funny - and sad - situations"
- WebMD: "Why do we laugh?"
Resources and activities:
- Y is for You- fingerprinting activity (ages 4-11)
- Spies and CSIs- fingerprinting activity (ages 4 and up)
- Family Traits and Traditions- Matching game (Grades 1-6)
- An Inventory of My Traits (Grades 5-7)
- Genome Educator Guide- chock full of resources! (Grades 7-12)
- Extract DNA with Stuff You Have at Home
- What Color Eyes Will Your Children Have? Online Exhibit