Behavioral genetic analysis on dogs

Abstract

The aim of this study is to describe personality traits in eight dog breeds using the Behaviour and Personality Description in Dogs (BPH) test, and subsequently to assess their heritability. The study population comprises 7425 individual dogs across eight different breeds. Factor analysis was used to identify five fundamental behavioral traits: 1) Playful behavior; 2) Flight and distancing behavior; 3) Sociality; 4) Socially threatening and fearful behavior; 5) Submissive behavior. The genetic analysis used the five identified phenotypic behavioral traits and the pedigree data recorded in the Swedish Kennel Club’s database for each of the eight breeds. Complete pedigree information was available for between 1514 and 8916 individuals. A mixed linear model was used to calculate the heritability estimates of the traits for each of the breeds. The research explores breed differences, revealing unique profiles for each breed while emphasising substantial within-breed variability. Behavioral genetics analysis indicates low to intermediate heritabilities, suggesting a genetic influence on these traits. In addition, the study highlights the effect of environmental factors—particularly test day—on canine behavior. There was a general lack of pattern in heritability estimates within each of the breed groups and when considering the breeds individually. High heritability values were found for factors 2 and 3 (Flight/distancing behavior and Sociality) in some breeds, but factor 3 was also associated with some of the lowest values. The most consistent trait was factor 2 (Flight and distancing behavior), hence it has the highest average $h^2$ estimate. Heritability can offer useful insights into the breeding potential for desired traits, such as sociability, playfulness and reduced aggression in animals. These findings provide a comprehensive insight into the complexity of canine behavior, offering valuable implications for breeding practices, training and understanding the diverse behavioral landscapes within and between dog breeds.