Rank-Related Differences in Dogs' Behaviours in Frustrating Situations.

Dogs are strongly dependent on humans, not only for sustenance, but they also form asymmetrical bonds with us where they rely on assistance from the human partner in the case of difficult situations. At the same time, cohabiting dogs form hierarchies, and their rank strongly influences their behaviour in various social interactions. In this study, we investigated whether high- and low-ranking dogs would behave differently in non-social and social contexts where a formerly available reward suddenly becomes inaccessible. We hypothesised that dominant and subordinate dogs would show different levels of human dependence; thus, they will show different levels and different signs of frustration depending on the social nature of the context, where the reward was locked either in a closed cage or withheld in the hand of the experimenter. The results showed that while the holistic rank ('dominant' vs. 'subordinate') of the dogs did not show a significant association with their reactions to frustrating situations, the rank components ('agonistic' and 'leadership' ranks) were better predictors of the dogs' behaviour. In the non-social context, the highly resource-oriented 'agonistic-dominant' dogs were more persistent with their attempts of getting to the reward. However, in the social context, the dogs with high 'leadership scores' behaved more demandingly with the non-complying experimenter. This study provides a first-time indication that the various aspects of dominance in dogs can affect their adaptive reward-oriented behaviours differently, depending on the potentially available human assistance.