This spring, when Science published 'Ancestry-inclusive dog genomics challenges popular breed stereotypes,' the reactions among dog people—owners, trainers, behaviorists, rescuers—were enormous. The study, which surveyed 18,385 dogs and sequenced the DNA of 2155 of them, found that breed identification, in both pure-bred and mixed breed dogs, offered little correlation to behavior on all but one of 8 behavior factors identified by the researchers. Combining all 8 factors showed only 9% of the variation to be attributable to breed ancestry. Strikingly, on the group of traits labeled 'agonistic threshold' (a more precise name for what people often think of as 'aggression'), a dog’s breed had no discernable predictive value at all. Only 'biddability' had much connection to breed. Biddability is defined as ' how readily the dog responds to human direction,' the sort of thing people often think of as how easy a dog is to train.
Here at NCRC, we weren’t surprised by the findings. Our white paper, 'The Relevance of Breed in Selecting a Companion Dog,' published in 2011, presented similar hypotheses. In it, Janis Bradley pulled together the conclusions of dozens of smaller studies that all pointed to a common conclusion: breed isn’t a great predictor of behavior, even in dogs bred selectively for specific traits.
But this remarkable new study does more than that. It is the first to compare genetic and behavioral data on a single large sample of subjects. Earlier studies either collected behavior information on one group of dogs and genetic information from a completely different group or even collected no behavioral data at all, simply relying on breed club descriptions of behavior. And the Darwin’s Ark study is the first to include a representative sample of mixed breed dogs. Earlier studies all focused on dogs identified as purebreds, thus muddying any distinction between genetic influence per se, and that part that might correlate with breed. And those groundbreaking approaches to the question of the connection between canine breeds and behavior make this a truly cutting edge work of science."