A test of the yawning contagion and emotional connectedness hypothesis in dogs, Canis familiaris

The idea that yawning contagion in humans is predicated on an empathetic response was recently extended to dogs following the report of cross-species contagious yawning in this species (human-dogs). We attempted to replicate contagious yawning in dogs and to investigate what conditions promote yawning contagion. We tested the emotional connectedness hypothesis, which predicts that contagious yawning is precipitated by exposure to (1) familiar model (primary caregiver) and/or (2) similar model (conspecific) stimuli, if contagious yawning is empathy related. In our sample of family-owned and rescue centre dogs we further predicted that rescue centre dogs would yawn contagiously less than owned dogs on the basis that they are more lacking in emotional closeness and have more weakly bonded relationships with their primary care provider than owned dogs. We also controlled for stress since stress can induce yawning. While we found that five of 19 dogs did yawn in response to an unfamiliar human yawning, we were unable to confirm contagion. Our results provide no support for empathy-based, emotionally connected yawning contagion in dogs and casts doubt on the recently documented phenomenon of cross-species contagious yawning. We interpret our findings as showing that if dogs are seen yawning contagiously then the contagion must be explained on less cognitively stringent grounds than empathy.