Dogs' social susceptibility is differentially affected by various dog-Human interactions. A study on family dogs, former shelter dogs and therapy dogs.

When pre-treated with social stimuli prior to testing, dogs are more susceptible to human influence in a food preference task. This means, after a positive social interaction they are more willing to choose the smaller amount of food indicated by the human, as opposed to their baseline preference for the bigger amount. In the current study we investigate if and how various forms of social interaction modulate choices in the same social susceptibility task, testing dogs with varying early life history (pet dogs, therapy dogs, former shelter dogs). In line with previous studies, dogs in general were found to be susceptible to human influence as reflected in the reduced number of "bigger" choices in the human influence, compared to baseline, trials. This was true not only for pet dogs with a normal life history, but also for dogs adopted from a shelter. Therapy dogs, however, did not uniformly change their preference for the bigger quantity of food in the human influence trials; they only did so if prior to testing they had been pre-treated with social stimuli by their owner (but not by a stranger). Pet dogs were also more influenced after pre-treatment with social stimuli by their owner compared to ignoring and separation; however after pre-treatment by a stranger their behaviour did not differ from ignoring and separation. Former shelter dogs on the other hand were equally influenced regardless of pre-treatment by owner versus stranger. In summary these results show that dogs' social susceptibility is modulated by both interactions immediately preceding the test as well as by long term social experiences.

The influence of voice familiarity and linguistic content on dogs' ability to follow human voice direction.

Domestic dogs are well-known for their abilities to utilize human referential cues for problem solving, including following the direction of human voice. This study investigated whether dogs can locate hidden food relying only on the direction of human voice and whether familiarity with the speaker (owner/stranger) and the relevance of auditory signal features (ostensive addressing indicating the intent for communication to the receiver; linguistic content) affect performance. N = 35 dogs and their owners participated in four conditions in a two-way object choice task. Dogs were presented with referential auditory cues representing different combinations of three contextual parameters: the (I) 'familiarity with the human informant' (owner vs. stranger), the (II) communicative function of attention getter (ostensive addressing vs. non-ostensive cueing) and the (III) 'tone and content of the auditory cue' (high-pitched/potentially relevant vs. low-pitched/potentially irrelevant). Dogs also participated in a 'standard' pointing condition where a visual cue was provided. Significant differences were observed between conditions regarding correct choices and response latencies, suggesting that dogs' response to auditory signals are influenced by the combination of content and intonation of the message and the identity of the speaker. Dogs made correct choices the most frequently when context-relevant auditory information was provided by their owners and showed less success when auditory signals were coming from the experimenter. Correct choices in the 'Pointing' condition were similar to the experimenter auditory conditions, but less frequent compared to the owner condition with potentially relevant auditory information. This was paralleled by shorter response latencies in the owner condition compared to the experimenter conditions, although the two measures were not related. Subjects' performance in response to the owner- and experimenter-given auditory cues were interrelated, but unrelated to responses to pointing gestures, suggesting that dogs' ability to understand the referential nature of auditory cues and visual gestures partly arise from different socio-cognitive skills.