Social Stimulation by the Owner Increases Dogs’ (Canis familiaris) Social Susceptibility in a Food Choice Task—The Possible Effect of Endogenous Oxytocin Release

Recent evidence suggests a human-like susceptibility to social influence in dogs. For example, dogs tend to ignore their &lsquo:natural&rsquo: preference for the larger amount of food after having seen a human&rsquo:s explicit preference for a smaller quantity. However, it is still unclear whether this tendency to conform to the partner&rsquo:s behaviour can be influenced by social stimuli and/or the neurohormone oxytocin as primers to prosocial predispositions. In Experiment I, eighty two dogs were tested using Prato-Previde et al.&rsquo:s food quantity preference task. In Experiment I, we investigated in a 2 &times: 2 design how (i) a 10-minute-long social stimulation by the owner versus a socially ignoring pre-treatment as well as (ii) on-line ostensive communications versus no communication during task demonstration affect dogs&rsquo: (N = 82) choices in the abovementioned food choice task. Results indicate that the owners&rsquo: pre-treatment with social stimuli (eye contact, petting) increased dogs&rsquo: susceptibility to the experimenter&rsquo:s food preference, but the salient ostensive addressing signals accompanying human demonstration masked this social priming effect. In Experiment II, N = 32 dogs from the subjects of Experiment I were retested after oxytocin (OT) or placebo (PL) pre-treatments. This experiment aimed to study whether intranasal administration of oxytocin as compared to placebo treatment would similarly increase dogs&rsquo: tendency to re-enact the human demonstrator&rsquo:s counterproductive choice in the same task. Results showed an increased susceptibility to the human preference in the OT group, suggesting that both socially stimulating pre-treatment and the intranasal administration of oxytocin have similar priming effects on dogs&rsquo: social susceptibility.