When the dog genome was sequenced in 2005, scientists thought they would quickly be able to pin down the genes that give every breed its hallmark personality. But they found so much variation even within a breed that they could never study enough dogs to get meaningful results.
So in the new study, Evan MacLean, a comparative psychologist at the University of Arizona in Tucson, and colleagues began by looking at behavioral data for about 14,000 dogs from 101 breeds. The analyses come from the Canine Behavioral Assessment & Research Questionnaire (C-BARQ), a sort of pet personality quiz developed by James Serpell, an ethologist at the University of Pennsylvania. C-BARQ asks questions like, “What does your dog do when a stranger comes to the door?” to allow owners to objectively characterize 14 aspects of their pet’s personalities, including trainability, attachment, and aggression. Since the survey was developed in 2003, more than 50,000 owners have participated.
The team matched up these behavioral data for each breed with genetic data about breeds from different sets of dogs. They didn’t look at genetic and behavioral data for individual dogs, but rather averages across a specific breed. In all, the team identified 131 places in a dog’s DNA that may help shape 14 key personality traits.
Together, these DNA regions explain about 15% of a dog breed’s personality, with each exerting only a small effect. Trainability, chasing, and a tendency to be aggressive toward strangers were the most highly heritable traits, the scientists report in a paper posted this month on the preprint server bioRxiv.