In case of investigating dog behaviour, the definition and usefulness of the terms ‘dominance’, ‘rank’ and ‘hierarchy’ became the subject of intense debate, not only among dog owners and trainers, but also behavioural researchers. These expressions are most commonly used by observers of groups of dogs, who want to describe the group structure and to infer the factors that are behind the observed behaviour. However, the actual driving force behind the competitive interactions of individual dogs are much simpler: their differences in relative strength, motivation levels and previous experiences. The question is if there is justification of using terms that merely make the observer’s job easier while they may lack the explanatory power about the mechanisms of social interactions.
To make matters worse, the term ’dominance’ has a different meaning in ethology, in human psychology and sociology and it is also a bit different in its everyday use. While in humans dominance is mostly regarded as a personality trait, in ethology it is only understandable as a qualitative measure of social relationships.
As this conflict in interpretation is primarily between different fields of science, it is not our job as ethologists to do justice to the debate. In our understanding, dominance is not a personality trait but it is a logical assumption that personality that has a strong influence on an individual’s social behaviour could also have an effect on the course and outcome of dog-dog interactions – hence on dominance relationships. More broadly, differences in personality traits of individuals in a group may affect the hierarchy built up by dyadic interactions and the individuals’ ranks. These were the main hypotheses behind our current research.
We conducted a large-scale online questionnaire study. We promoted the survey on social media in English and Hungarian. The questionnaire consisted of three main parts: demographic data of the dog (age, sex, etc…); interactions between dogs living together that are related to dominance relationships (obtaining resources, outcomes of conflicts, etc…); and finally, personality. For the latter, we used the Canine Big Five inventory. The only criterion of the questionnaire was that the participating owners had to have more than one dogs living together. We only included the data of dogs more than one year old, because both personality and social behaviour still rapidly change in puppyhood.
We analysed the entries about 1082 dogs. The five personality traits that can be derived from the Big Five inventory are Extraversion/Energy, Agreeableness/Affection, Conscientiousness, Neuroticism an Openness/Intelligence (descriptions of these traits can be found in the ’Results’ menu at https://socialdogs.elte.hu). Four of these traits had a significant association with the ’dominance score’ that we calculated from the questions regarding the dog-dog interactions. This score basically shows the dog’s rank in the hierarchy.
According to the results, the more extraverted, conscientious and open dogs usually have higher ranks, while there was a negative association between agreeableness and the dominance score. We also confirmed the association between dogs’ age and their dominance rank: similarly to previous studies we found that older dogs are more likely to be dominant. As personality can slowly change with age, we needed to check whether our results still hold regardless of age. We found negative correlations between age and extraversion and age and openness while these traits have positive associations with rank. Agreeableness had a similarly negative correlation with age and a negative association with the dominance score (older dogs are less agreeable, more agreeable dogs rank lower).
We also asked the owners about their opinions on which of their dogs is the dominant one and checked if the answer correlates with the calculated dominance score. We found that owners can judge the hierarchy between their dogs with considerable accuracy.
Several different experiences, many of which are not related to competitive situations are involved in the development of personality traits of dogs. While our results support the notion that ’dominance’ is not a separate personality trait in dogs, we found that the personality of family dogs have a complex relationship with the group hierarchy and the individual dogs’ rank within. Further research is needed to discover, what causal relationships may exist between personality traits and rank.