S1 Dataset -

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.