Social eavesdropping in domestic dogs

Eavesdropping on third-party interactions has been observed in a number of species and is considered an important source of information in decision-making processes relating to fighting and mate choice. Human beings, however, use publicly available information flexibly in many different contexts including assessing others' altruistic tendencies, which may in turn inform their choice of the most appropriate cooperative partner. We assessed whether dogs, Canis familiaris, were capable of discerning a generous versus selfish food-sharing interaction between humans, and investigated which communicative cues (voice versus gestures) may be more salient for them. Importantly a control condition was included to ascertain whether it was in fact the interaction between individuals as opposed to the direct actions of the actors that the dogs evaluated. We found that the dogs were capable of eavesdropping on human food-sharing interactions, and vocal communication was particularly important to convey the human's cooperative versus noncooperative intent.