New data suggests we may be unfairly stereotyping dogs.
Modern breeds are often recognized by physical traits. The bat-like ears of Chihuahuas. The curly hair of poodles. The long bodies and short legs of dachshunds. Races are also frequently associated with certain behaviors. The American Kennel Club describes border collies as “loving, intelligent, energetic,” for example. Beagles are “friendly, curious, happy”.
But new evidence suggests that breed is a poor predictor of your dog’s behavior. One study collected genetic information from over 2,000 dogs. This information was combined with survey responses from thousands of dog owners. On average, breed explains only 9% of behavioral differences between dogs, according to the study.
The researchers shared their findings on April 29 Science.
Elinor Karlsson studies canine genetics. She works at Chan Medical School at the University of Massachusetts in Worcester. “Everyone assumed that breed was predictive of behavior in dogs,” she said at a press conference on April 26. But “it had never really been particularly well asked”.
A 2019 study linked genetics to some variation between breeds as a whole. Genes could explain some of the differences between, for example, the behaviors of poodles and chihuahuas. But Karlsson and his colleagues wanted to know more about the individuals. How well does a given breed predict a dog’s behavior?
Calling all dogs
For this, the team needed genetic and behavioral data from a large number of dogs. So they developed Darwin’s Ark. It is a database where pet owners can share information about their pets. More than 18,000 owners took part. They answered over 100 questions about their dog’s observable traits and behaviors. The researchers then grouped this data into eight “behavioral factors”. One factor was how comfortable a dog is around people. Another was the way it responds to commands.
The researchers also collected genetic data from 2,155 dogs. These included 1,715 dogs from Darwin’s Ark where owners had sent swabs of dog saliva. The team made sure to include both purebred dogs and mixed-breed dogs, or pooches. Stereotypes about pure breeds could affect how these dogs are treated – and therefore behave. Pooches don’t have the same expectations. So data from mutt could help focus on how genes seem to affect behavior.
Studying mutts also helps separate traits that often occur together in purebreds, says Kathleen Morrill. She’s a geneticist in Karlsson’s lab. “And that means on an individual basis, you’ll have a better chance of [identifying] a gene that is actually related to the question you are asking.
The team then combined the genetic and survey data for the individual dogs. They looked for genes that seemed linked to particular traits. Comfort around people emerged as the behavioral factor most strongly linked to genetics. Movement-based behaviors – such as howling and fetching – are also passed down through genes more than other traits.
It makes sense, Kathryn Lord said during the briefing. She studies the evolution of the dog with Karlsson. Modern animal husbandry has only been around for a few hundred years. Before that, dogs were chosen for the quality of their work, such as hunting or herding. The effects of these choices can still be seen today in racial groups. For example, sheepdogs tend to respond well to commands and are interested in toys.
So it’s no surprise that a breed as a whole is more likely to display certain behaviors. As their name suggests, Retrievers are more likely to recover than individuals of other breeds.
But in the study, breed did not always predict an individual dog’s behavior. As a group, retrievers were less likely to howl. Some owners, however, have reported that their retrievers often howl. And greyhounds rarely bury toys – although a few do.
As individual as people
The results confirm what people have observed: dog breeds differ on average in their behavior. Still, there’s a lot of variation within races, says Adam Boyko. He did not participate in this project. He is, however, studying canine genetics at Cornell University in Ithaca, NY.
Body size had even less of an effect on an individual dog’s behavior. That might come as a surprise, Boyko notes. It is often thought that small dogs are more barking than large ones, for example. In fact, size had almost no effect on zest for life. If small dogs behave worse than big dogs, Boyko says, it might have little to do with their genetics. “I think it’s that we’re generally more tolerant of bad behavior in small dogs than in big dogs,” he says.
Curtis Kelley is a dog trainer at Pet Parent Allies in Philadelphia, Pennsylvania. “Dogs are as individual as people,” he found. Breed gives a loose directive on what kind of behaviors to expect. “But it’s certainly not an absolute rule.”
When looking to buy a dog, he says, don’t give too much importance to its breed. Even within the same litter, dogs can show very different personalities. “A puppy will show you who he is at eight weeks,” he says. “It’s just our job to believe them.”