Dogs avoid people who behave negatively to their owner: third-party affective evaluation

Social eavesdropping, or social evaluation of third-party interactions, is a first step to image scoring, which is a key feature of humans' large-scale cooperative society. Here we asked whether domestic dogs evaluate humans interacting with one another over neutral objects. In two experimental conditions, the dog's owner tried to open a container to get a junk object that was inside, then requested help from an actor sitting next to her/him, while the dog watched the interaction. In the Helper condition, the actor held the container stable to help the owner to open it. In the Nonhelper condition, the actor turned away and refused to help. In the Control condition, the actor simply turned away in the absence of any request for help. A neutral person sat at the other side of the owner throughout these interactions. After the interaction the actor and the neutral person each offered a piece of food to the dog. Dogs chose food randomly in the Helper and the Control conditions, but were biased against the actor in the Nonhelper condition. The dogs' avoidance of someone who behaved negatively to the owner suggests that social eavesdropping may be shared with a nonprimate species.