Contagious Yawning in People and Dogs the Same and Different
Contagious yawning in people associated with empathy is a myth, at least in part, according to new research. However, other studies on yawning in dogs suggest something different.
How many times have you told someone, “Hey, don’t do that or I’ll start yawning too!” Although you may yawn after seeing another person do the same thing, Duke University investigators report that contagious yawning is not strongly linked with empathy, your energy level, or how tired you feel.
In fact, the researchers discovered that age seems to beat these other factors when it comes to contagious yawning. One of the study’s authors, Elizabeth Cirulli, an assistant professor of medicine at Duke University School of Medicine, noted in USA Today that while “Empathy does play a role…it’s just not the huge role people were thinking.”
Basically, the authors found that the younger you are, the more likely you are to respond to a yawn with the same. They arrived at this conclusion after testing 328 healthy adults.
All the participants were evaluated using scales to determine factors such as empathetic traits and cognitive performance, and they also watched a video of contagious yawning. Then, 129 of the volunteers watched the same video again, and those who yawned the first time tended to do the same thing again.
Overall, when all factors were considered, the authors found that age was the only factor clearly associated with contagious yawning. What the study did not uncover, however, is why age does not explain much of the differences among people when it comes to this activity.
For that explanation, investigators with this study and from previous research suggest genetics may have a role. Social factors also may be involved.
Yawning and dogs
What about man’s best friend? According to several studies, dogs yawn out of empathy with their two-legged companions. Here’s the tail-wagging evidence.
In a recent study published in PLoS One (August 2013), the authors pointed out the following previous findings on yawning and dogs:
- Dogs yawned contagiously when exposed to people yawning and that they yawned more when the yawn was familiar than unfamiliar
- 72 percent of dogs yawned after they saw a human experimental act out a yawn
The new study involved 25 dogs who were at least one year old, who had lived with human companions, and who were comfortable with strangers. In this study, the authors hoped to discriminate between empathy and distress as the reason why dogs yawned.
All the dogs were exposed to both yawns and controlled mouth movements by their owner and a stranger. Here’s what happened:
- Contagious yawns occurred significantly more when the dogs observed yawns than controlled mouth movements
- Dogs yawned more often when they saw their owner than when they observed a stranger
- Heart rate did not differ among the dogs regardless of which person was yawning, which suggests contagious yawning in dogs is not related to stress
Therefore the authors concluded contagious yawning in dogs “may indicate that rudimentary forms of empathy could be present in domesticated dogs.”
In a study published in November 2013, the investigators studied 29 dogs who had lived with their human companions for at least six months. The dogs were exposed to three different types of recorded yawns: those of their human companions, those of an unfamiliar woman, and a computer-simulated yawn. Here are the findings:
- Nearly 50 percent of the dogs yawned after hearing a human yawn
- Dogs were five times more likely to yawn when the sound was from their owners
The bottom line
People engage in contagious yawning as well as yawns that are associated with stress and tiredness. Yawning also helps keep the brain cool and transport more oxygen to the brain.
Similarly, dogs also appear to yawn for all the same reasons their human companions do. Some experts believe dogs also yawn as a way to develop social connections with other dogs.
But when it comes to empathy, dogs may have the upper hand (paw). Empathy in relation to contagious yawning in people seems to be less significant than it does in dogs, but then again, there’s much we don’t yet know about this extremely common behavior.
Bartholomew AJ, Cirulli ET. Individual variation in contagious yawning susceptibility is highly stable and largely unexplained by empathy or other known factors. PLoS One 2014 Mar 14.
Romero T et al. Familiarity bias and physiological responses in contagious yawning by dogs support link to empathy. PLoS One 2013 Aug 7; 8(8): e71365
Silva K et al. Familiarity-connected or stress-based contagious yawning in domestic dogs (Canis familiaris)? Some additional data. Animal Cognition 2013 Nov; 16(6): 1007-9