‘Puppy Dog Eyes’ Are Associated With Eye Movements, Not Communication

The inner brow raiser is a muscle movement that increases the size of orbital cavity, leading to appearance so-called ‘puppy dog eyes’. In domestic dogs, this expression was suggested be enhanced by artificial selection and play an important role in dog-human relationship. Production has been shown sensitive attentive stance human, suggesting possible communicative function. However, it not yet examined whether human presence. current study, we aimed test differs depending on presence or absence observer. We used two versions paradigm equivalent experimental setting which dogs were trained expect reward; however, presence/absence person apparatus varied. social context, facing delivered non-social reward delivery automatized. If function adjust its audience, more frequently context (when apparatus) than without inside). frequency differed between contexts, but contrary prediction, context. further demonstrate strongly associated with eye movements occurs independently only 6% cases. This result challenges hypothesis interactions suggests lower-level explanation for production, namely association movements.