We’ve all heard about how yawns can be ‘contagious’ – if you see or hear someone yawn, it makes you more likely to do likewise. But now it seems that wolves experience contagious yawning too, with important potential implications about empathy.
Research suggests that in humans contagious yawning is linked to empathy, the ability to share the feelings of others. For example, the higher you score on questionnaires evaluating empathy, the more frequently you experience contagious yawning1. The phenomenon might therefore be a useful indicator to explore empathy in other species.
Previously, it was found that primates show contagious yawning, and it seems that dogs may also yawn in response to a human yawn2. It was unclear, however, if the behaviour in dogs was evolutionarily ancient, or if it had evolved during domestication, as dogs got better at reading human communicative signals.
Now, a study led by Dr Teresa Romero along with colleagues at the University of Tokyo has found that wolves also experience contagious yawning. They recorded when an initial wolf yawned in the absence of external stimuli and in a relaxed setting, then looked for subsequent yawns in other wolves nearby and recorded the time lapse. They also observed emotional relationships between different wolves by assessing how they interacted with each other.
The researchers found that wolves were significantly more likely to yawn after seeing another wolf yawn than if no previous yawn had been observed, i.e. contagious yawning did occur. This indicates that the phenomenon is a trait that was present even before domestication of the dog.
Interestingly, the yawn seemed to be more ‘contagious’ (the wolf observing the initial yawn was more likely to yawn subsequently) if the wolves were emotionally close. This correlation would suggest that contagious yawning is indeed linked to empathy: wolves are more likely to feel empathy with individuals with which they have a stronger social bond, and hence their yawns are more contagious. It is striking that females were particularly affected by the strength of the social bond and were quicker than males to yawn in response to an initial yawn from a wolf they were emotionally close to – they are seemingly more responsive to nearby social stimuli.
Although the sample size of this study was small, it provides evidence that contagious yawning may have evolved before the domestication of the dog. The authors state: “our results trace back to carnivores the link between contagious yawning and empathy, supporting the idea that basic building blocks of empathy might be present in a wide range of species”.
Next time you’re at the zoo, try yawning at a wolf. If you’re contagious (or boring!) enough, who knows – they might just yawn back!
Full paper available at: http://dx.plos.org/10.1371/journal.pone.0105963
1Platek SM, Critton SR, Myers TEJ, Gallup GG (2003) Contagious yawning: the role of self-awareness and mental state attribution. Cogn Brain Res 17: 223–227.
2Joly-Mascheroni RM, Senju A, Shepherd AJ (2008) Dogs catch human yawn. Biol Lett 4: 446–448.