Have you ever been sitting in class and you see someone yawn, and then you yawn, and then everyone else starts to yawn? Is there a part of science that explains why this happens? Maybe there is a mechanism that triggers the response in people to yawn. Let’s check out some studies I found online.
The first study I came across was an observational study done by scientists in Switzerland, in which 11 volunteers watched a set of videos. Their brain activity was monitored through a fMRI to measure the mirror neuron network. The participants watched videos that displayed humans laughing, yawning, or with neutral expressions. The results showed that participants yawned more than half of the time when the video of yawning faces appeared on the screen,and not the same reaction when laughing or neutral expression came on the screen.This had a chain reaction among the participants. The fMRI signal lit up the frontal gyrus, which allows for mental representations of action.
Now, this study is pretty small, which could lead us to believe that third variables could have a large correlational or causal effect on the contagious yawning. To improve this study, running a larger sample would be more accurate. This allows for less error and allows use to believe the study is credible.
Another study I found was conducted by Elizabeth Cirulli at Duke University. The study measured certain variables that affect contagious yawning. 328 people participated and they were required to fill out a survey and questionnaire that measured 15 variables, including sleepiness, demographics, and empathy. Within the study, participants watched a three-minute video and then recorded the number of times they yawned during it. Out of the 328 people, 222 yawned contagiously at least once. Results showed that age was only a small percentage of variation in results. This means all the other variables could have showed correlation as well.
However, in previous studies, researchers have said that empathy and sleepiness do not show enough evidence to prove that they are correlated to contagious yawning. With such small evidence, the Duke study shows that not enough studies are done to which variables actually cause the chain reaction of yawning.
This study had a large enough sample, however we discussed hard endpoints versus soft endpoints in class. I would recommend using hard endpoints rather than the soft endpoints. This will allow for more experimental evidence to be provided.