Showing Behaviour in One Hundred and One Dogs: Gazing, Breed and Cephalic Index.

Dogs exhibit sophisticated interspecific communication skills, including the use of visual signals to indicate the location of inaccessible resources, known as showing behaviour. Previous studies have investigated factors such as age and training, but the effects of breed and cranial morphology remain unclear. Here, we tested a uniquely large sample of 101 pet dogs from 43 different breeds, using a standardized out-of-reach/hidden object task to assess three key visual behaviours: gaze at the owner, gaze at the reward, and gaze alternation between owner and reward. Dogs were tested in familiar environments without pre-training, and owners were instructed to remain passive to avoid unintentional cues. Our results confirm the importance of gaze alternation and gazing at the reward as central components of showing behaviour, particularly when both owner and reward were present. Contrary to expectations, we found no effect of breed or Cephalic Index on these behavioural patterns, suggesting that life experiences rather than artificial selection can influence visual communicative strategies in this specific context. The exceptionally large and diversified sample of this study provides unprecedented insight into the consistency of visual signalling across dog breeds.