A new study suggests that contagious yawning is not triggered of empathy, sleepiness, or exhaustion. This finding may drive another study which can focus more on the genetic variant, rather than social factors.
Yawning occurs commonly before and after sleep, or right after tiresome activities. It is usually associated with exhaustion, stress, overwork, and boredom. Other studies have linked it to the cool down of brain. However, there is a phenomenon that scientists are still unable to explain-contagious or infectious yawning. This is usually seen in humans and other species such as chimpanzees and dogs.
Some scientists also considered contagious yawning as a measurement of the level of empathy existing among individuals. They suggested that the closer the members of the group are to one another; they are more likely to yawn simultaneously due to stronger empathic social bonds.
However, a new study conducted by researchers from the Duke University Medical Center, led by professor of medicine Elizabeth Cirulli, disagreed with these earlier findings. They recruited 328 people for their yawning experiment. They captured the yawning incidents of the participants in video in which the instances of yawn captured in 3 minutes were in between zero and 15 times. Contagious yawning was observed only once in 222 participants.
To measure the level of empathy, tiredness, and sleepiness of the participants, the researchers asked them to answer a questionnaire. Based on the analysis of the responses provided, they didn't see any strong relationship between contagious yawning and the level of empathy, tiredness, and sleepiness of the respondents.
However, they were able to find a common denominator of the participants-age. They noticed that, as the age increases, the number of yawns decreases. The researchers admitted though that age is not a clear basis because it still failed to explain the reason behind contagious yawning.
The fact that this study provided evidence that there is no direct association between empathy and contagious yawning; it will help researchers direct their attention on looking at other factors, particularly genetic variants. There was an observational study conducted by another team showing that children with autism are unaffected by contagious yawning. The researchers linked it to the activities of the brain cells.
"It is possible that if we find a genetic variant that makes people less likely to have contagious yawns, we might see that variant or variants of the same gene also associated with schizophrenia or autism," Cirulli said in a university news release. "Even if no association with a disease is found, a better understanding of the biology behind contagious yawning can inform us about the pathways involved in these conditions."
This study was published in the March 14 issue of PLOS One.
