The influence of genes on personality and behavior is of great interest to people who love dogs as well as to scientists studying the genetics of animal behavior. Since dogs’ personalities play a major role in their ability to function as our companions as well as to carry out a variety of tasks as working dogs, it’s important to understand the contribution of genetics on behavior. It is well established that genetics plays a large role, as evidenced by behavioral differences between breeds. Even substantial differences in behavior within breeds can be accounted for by genetic variation.
One of the challenges to studying behavioral genetics is that large sample sizes are required because there are so many factors that influence behavior (e.g. early environment, training methods, various lifestyle factors). To achieve adequately large sample sizes in research is both expensive and time consuming, sometimes prohibitively so. A recent study called “Genetic Characterization of Dog Personality Traits” took a creative approach to meet this challenge.
The scientists were interested in genetic contributions to personality, defined as “individual consistency in behavioral responsiveness to stimuli and situations”. Researchers took advantage of the substantial knowledge people have about their own dogs’ personalities to explore genetic contributions to personality traits. Their work shows that it is possible to detect genetic variation in dog personality traits by using questionnaires to collect large quantities of useful data.
In this recent study, researchers used the C-BARQ (Canine Behavioral Assessment Research and Questionnaire) as well as a separate questionnaire about demographics to study 1975 UK Kennel Club-registered Labrador Retrievers. The C-BARQ allowed each dog to be scored for the following personality traits—Agitated When Ignored, Attention-Seeking, Barking Tendency, Excitability, Fetching, Fear of Humans and Objects, Fear of Noises, Non-Owner Directed Aggression, Owner-Directed Aggression, Separation Anxiety, Trainability and Unusual Behavior.
The additional questionnaire collected data about the dog’s age, coat color, sex, neuter status, housing, health status, exercise, daily exercise and the role of the dog. (The various roles were gun dog, show dog and pet dog.) To gather genetic information, the study took advantage of the dogs’ pedigrees, which involved 29 generations and 28,943 dogs. Further genetic data on the dogs were obtained as part of a different study using standard genomic methods and genetic markers, with 885 dogs from that study also participating in the C-BARQ portion of the research. In the analysis, the researchers estimated heritability of personality traits based on both the pedigree and on the genomic data.
The researchers found that fetching has a higher heritability rating than any other personality trait. Interestingly, some previous studies have lumped trainability with fetching ability, which results in lower heritability scores for both of them. This study also revealed a considerable genetic component to the fear of noises. Aggression directed towards owners showed no genetic component at all, while aggression towards strangers had a moderate genetic component.
Many behavioral traits are polygenic (influenced by a large number of genes, with each one often having a small effect) and also have significant environmental influences, which means that it is difficult to determine genomic associations. Estimates of heritability are likely to increase with technological advances in genetic work.
The importance of this study is that it shows that genetic variance can be detected and studied with the use of questionnaires filled out by owners. It also reveals that grouping responses into behavioral factors may make it harder to detect the genetic influence on various traits.