Svartberg, K. 2022. A possible basis for personality in dogs: Individual differences in affective predispositions. Applied Animal Behaviour Science 255, 105740.

Previously, dog personality traits that seem to correspond have been identified by the Dog Mentality Assessment (DMA) and the Behaviour and Personality Assessment in Dogs (BPH): Playfulness, Sociability, Curiosity/fearlessness (DMA) vs. Non-social fearfulness (BPH), Aggressiveness, and Boldness. The first aim was to study the relationship between these traits. Correlation analyses on data from 1078 dogs subjected to both assessments revealed moderate correlation for Aggressiveness (r = 0.25) and high correlations (r = 0.47–0.59) for the other four corresponding traits, which indicates that they reflect similar aspects of dog personality. Considerable correlations were found after up to four years between assessments, suggesting temporal stability over longer periods of time. The second aim was to analyse the data set from a core-affect point of view. Two major dimensions were identified using principal component analysis and multidimensional scaling analysis (MDS). The first dimension was correlated positively with object play, pro-social behaviour, and exploration, and negatively correlated with fear-related variables, whereas the second dimension had its highest correlations with variables related to aggressiveness. The MDS analysis suggested a circular arrangement of the assessment variables in two-dimensional space, implying that several aspects of the assessed behaviour were related to both dimensions. The correlation pattern for data from a questionnaire related to everyday behaviour was in line with the results and provided additional information about the character of the two-dimensional space. The two dimensions may, at a state level, be interpreted as valence and arousal, respectively, and seem to reflect core affect in dogs. At a trait level, the dimensions seem to represent boldness and impulsivity, respectively. The second dimension may also indicate a coping strategy in challenging situations. From this point of view, the assessed behaviour may serve as the observable indicator for both stable personality and temporary affective states. Thus, the personality traits may, at least partly, be defined as individual differences in affective predispositions. From the current results, an affect-based model may be elaborated in which profiles of individual dogs or groups of dogs can be identified by the DMA and the BPH. There are several possible applications, for example in the identification of affect-related markers for problem-causing behaviour, welfare, and working performance in dogs. Due to the similarities with affect- and personality-related models used in humans, the two-dimensional space may be useful in comparative studies in areas such as genetics, well-being, mental health, and personality.