Genetic parameters of personality traits in dogs based on behavioral assessment and questionnaire information

A new behavior and personality assessment in dogs (BPH) was created in Sweden in 2012. Since the start of BPH, questionnaire data based on an extended version of C-BARQ have been collected to describe the everyday behavior of dogs. Our aim was to estimate genetic parameters for personality traits based on BPH or questionnaire data for eight breeds: American Staffordshire Terrier, Golden Retriever, Labrador Retriever, Lagotto Romagnolo, Nova Scotia Duck Tolling Retriever, Perro de Agua Espanol, Rhodesian Ridgeback, and Staffordshire Bullterrier. The number of BPH records ranged from 862 for Lagotto Romagnolo to 2462 for Labrador Retriever. Average heritability across all breeds was 0.22 for Sociability, 0.23 for Playfulness, 0.16 for Non-social fearfulness, 0.26 for Aggressiveness, and 0.22 for Boldness; all traits defined based on BPH. The genetic variation between breeds was larger than the genetic variation within breeds for Sociability, Playfulness, and Boldness. Estimates of heritability for questionnaire traits were more variable, possibly owing to fewer observations, and averages ranged from 0.06 to 0.28. Genetic correlations between BPH traits, on the one hand, and corresponding questionnaire traits, on the other hand, were consistently strong between Sociability and Stranger-directed interest (average 0.93) and Stranger-directed fear (-0.89); between Playfulness and Human-directed play interest (0.77); between Non-social fearfulness and Non-social fear (0.77); between Aggressiveness and Stranger-directed aggression (0.57); and between Boldness and Stranger-directed interest (0.78) and Stranger-directed fear (-0.80). Often, we could also see that a measure at BPH involving human interactions also extended to measure reactions to interactions with other dogs, e.g., a strong genetic correlation between Sociability and Dog-directed interest (0.58). In summary, selecting dogs based on traits defined at BPH is expected to result in behavioral changes not only when measured at BPH but also changes in everyday behavior in an expected way.