This post is about humans, but I couldn’t help uploading this picture.  Just look at the puppy, it’s so cute!  Anyway, I’ve grown up being told that yawning is contagious.  I’ve always found this to be quite interesting.  Most people are under the impression that yawning is contagious for reasons such as empathy, energy levels, or tiredness.  Well, a new study from Duke University suggests that this isn’t the case at all.

This is the most comprehensive study about contagious yawning to date.  The study involved taking 328 healthy volunteers and having them complete cognitive testing, a demographic survey, and a comprehensive questionnaire that measured empathy, energy levels, and sleepiness. Then they watched a three minute video of people yawning and recorded how many times it made them yawn (Duke Medicine para. 8). Of the 328 people studied, 222 contagiously yawned at least once, and the participants that did yawned between one and 15 times during the video (Duke Medicine para. 10).

So if it wasn’t empathy, energy levels, or tiredness, what was it that made these people contagiously yawn? Researchers found that the only independent factor that significantly influenced contagious yawning was age.  As their age increased, participants were less likely to yawn at the video (Duke Medicine para. 11).

Study author Elizabeth Cirulli, Ph.D., assistant professor of medicine at the Center for Human Genome Variation at Duke University School of Medicine, elaborates, “Age was the most important predictor of contagious yawning, and even age was not that important. The vast majority of variation in the contagious yawning response was just not explained” (Duke Medicine para. 12).

Even after conducting this extensive study, contagious yawning still largely remains a mystery to scientists.  At least now they have age as a hint or stepping stone to work off of.  It’s amazing to me that something so simple can still remain so inexplicable.

In my opinion, this experiment was well-executed.  The conductors of the study were sure to get a diverse group of volunteers.  If they had not done this, it might not have been possible to discover age as a factor.  Reverse causation was not a possibility in this experiment because the video can cause participants to yawn, but the participants’ yawning cannot do anything to the video.  If these results are incorrect and age is not a factor, it would be a false negative.

Works Cited:

Duke Medicine News and Communications. “Contagious Yawning May Not Be Linked to Empathy; Still Largely Unexplained.” Duke Medicine. N.p., 14 Mar. 2014. Web. 22 Oct. 2014. <http://corporate.dukemedicine.org/news_and_publications/news_office/news/contagious-yawning-may-not-be-linked-to-empathy-still-largely-unexplained>.