Your Dog’s Breed Doesn’t Determine Their Personality, Study Finds | Science

When Kathleen Morrill was 12, she decided she needed a puppy. Not just any puppy – a pint-sized butterfly with a black button nose and fluffy, perky ears. When her parents resisted, “I opened the aqueduct,” laughs Morrill, now a graduate student at the University of Massachusetts, Worcester. And so the family ended up with their first dog – a 2-month-old puppy they named Tod.

Tod was registered with the American Kennel Club (AKC), whose website describes his breed as “curious” and “friendly” with a “sturdy build.” But the pup was shy and afraid of strangers, and he developed separation anxiety as he got older. When Morrill’s family had another butterfly, Rosie, a year later, she was completely different: bold, outgoing and adoring of everyone. “Breed may be important,” Morrill says, “but it’s not a complete picture of a dog’s behavior.”

Now she has the science to back it up. In a new study, Morrill and colleagues show that almost none of the behaviors we associate with dog breeds, from lovable Labradors to pugnacious pit bulls, are hard-wired. Aside from a few old traits, environment seems to play a much bigger role than pedigree.

“It’s a major step forward in the way we think about dog behavior,” says Elaine Ostrander, a canine genetics expert at the US National Human Genome Research Institute, who was not involved in the works. “No race has a particular trait.”

Morrill wanted to better understand whether behavior problems such as aggression and obsessive-compulsive disorder in dogs are genetic or environmental. “If they’re more prominent in particular breeds,” she says, “that suggests they may be genetic.”

Previous work had found genetic relationships between breed and behavior, but looked at averages between breeds rather than comparing individual dogs. So Morrill and his colleagues tapped into his lab’s own database, Darwin’s Ark, which has collected investigative and genetic data on thousands of dogs across the United States since 2015. Owners respond to more than 100 questions, ranging from their puppies’ friendship with strangers to whether they enjoy hunting squirrels and then sending a mouth swab for DNA sequencing.

In the largest study of its kind, the team compared genetic and survey data from nearly 2,000 dogs – most of whom had their entire genomes sequenced – and survey results from an additional 16,000 pooches. Puppies included mixes and purebreds, with 128 breeds represented.

When it comes to physical traits, such as height and droopy ears, genes ruled. At least 80% of a dog’s appearance can be linked to its DNA, the team found.

Behavior was another story. Less than a quarter of personality differences between dogs could be explained by genetics. Some behaviors, like object retrieval and human sociability, were more hereditary. Researchers believe that scavenging may have helped the wolf ancestors of dogs to hunt, and that humans likely selected friendly mutts early in dog domestication.

But most of the behaviors didn’t have a strong genetic component, including playing around other dogs and (yes, that was in the survey) if a dog turns around before defecating. “It probably has a lot more to do with where you take your dog to poop,” says Elinor Karlsson, director of vertebrate genomics at the Broad Institute, who supervised the study.

And when it came to dog breeds, personality varied greatly within a single pedigree. Labradors can be affectionate or aloof. German Shepherds, easy to train or incredibly stubborn. Only 9%, on average, of personality differences between puppies were related to their breed, the team reports today in Science.

Some breeds have even challenged their stereotypes. Pit bulls, for example, (although they are not an official AKC breed) were no more aggressive than other dogs, despite their reputation as dangerous in some circles. The results, says Karlsson, “match what the canine world has told us” that these animals’ behavior is shaped by their environment, not their breed.

No race has a particular trait.

  • Elaine Ostrander
  • US National Institute for Human Genome Research

The bottom line, she says: If you’re looking for a dog with a specific personality, “you shouldn’t buy off the shelf. Each dog is an individual. (A website created by the team shows how hard it is to know what you might get.)

Personalities aside, most races To do have a distinct look, likely because breeding for appearance is much easier than breeding for behavior, says Adam Boyko, a dog genetics expert at Cornell University who was not involved in the work. Breeding for behavior could also have downsides, he says. “Anything that alters one brain pattern that much is likely to have negative effects in other areas.”

Yet after decades of treating, exposing, and judging countless breeds, AKC Chief Veterinarian Jerry Klein disputes the study’s findings. “I think most dogs conform to their breed’s personality standard,” he says. Supposedly older breeds, he says, like Tibetan mastiffs and basenjis — few of which have been enrolled in the study — may have more wired personalities because they’ve been around longer.

Klein also argues that if researchers looked beyond breed to classes of dogs — like sporting dogs (which include a variety of spaniels) and scent hounds (like bassets and beagles) — they would find that their behaviors are more similar to each other. than they are for other dogs. “It’s not as simple as races.”

At least Morrill hopes the work will unlock new insights into doggo’s personality. The team found 11 new DNA regions linked to behavior, including one for howling and another for sociability; in humans, these regions are respectively related to language and long-term memory. These could one day help scientists treat neurological disorders in puppies and humans, she says.

Tod passed away a few months ago, just before his 15th birthday. He became more confident as he got older, which Morrill attributes to Rosie’s reassuring presence. Her personality wasn’t tied to her race — nor was it fixed, she says. “Dogs, like people, can change over time.”