Domesticated dogs’ (Canis familiaris) use of the solidity principle


Organisms must often make predictions about the trajectories of moving objects. However, often these objects become hidden. To later locate such objects, the organism must maintain a representation of the object in memory and generate an expectation about where it will later appear. We explored adult dogs’ knowledge and use of the solidity principle (that one solid object cannot pass through another solid object) by evaluating search behavior. Subjects watched as a treat rolled down an inclined tube into a box. The box either did or did not contain a solid wall dividing it in half. To find the treat, subjects had to modify their search behavior based on the presence or absence of the wall, which either did or did not block the treat’s trajectory. Dogs correctly searched the near location when the barrier was present and the far location when the barrier was absent. They displayed this behavior from the first trial, as well as performed correctly when trial types were intermingled. These results suggest that dogs direct their searches in accordance with the solidity principle.


Shannon M. A. Kundey, Chelsea Taglang, Ayelet Baruch, and Rebecca German, Department of Psychology, Hood College; Andres De Los Reyes, Comprehensive Assessment and Intervention Program, Department of Psychology, University of Maryland at College Park. We would like to thank Jessica Arbuthnot, Rebecca Allen, Ariel Coshun, Erica Royer, Sherry McClurkin, Sabrina Molina, and Robin Reutten for their assistance in data collection and participant recruitment for this study.