Effects of learning on social and nonsocial behaviors during a problem-solving task in shelter and pet dogs

Many lines of evidence show differences between the communicative skills and social responses of dogs kept in shelters (SHDs) for long periods of time compared with pet dogs (PDs). The purpose of this work is to investigate whether there are also differences between these groups in a nonsocial problem-solving task consisting of dislodging nine plastic bones placed in a bowl to obtain the food hidden underneath it. The procedure comprised 3 phases: reinforcement, extinction, and reacquisition. In study 1, a second goal was to study whether, in the course of resolving the said task, the dogs exhibit different social responses in the presence of a stranger who remained seated near the apparatus in a passive attitude throughout the test. Results demonstrated that PDs spent longer time interacting with the apparatus throughout the 3 phases, which probably indicates greater persistence of reward-seeking behavior, compared with SHDs. This difference may relate to the fact that PDs have been more frequently exposed to partial reinforcement processes during their everyday life and have thus increased their resistance to extinction. On the other hand, during the extinction phase when no food was left, SHDs remained near for a longer time and gazed more at the person than PDs. This might indicate that the person was a stronger stimulus for SHDs as they are more deprived of social contact with people in their everyday life, which proves how the experiences during ontogeny shape the relationship between dogs and humans. The second study showed that PDs spent more time interacting with the apparatus compared with the SHDs, even in the absence of the person. These results indicate that PDs are more persistent in the reward searching response, whereas SHDs have a higher social motivation.