Your dog’s breed does not determine his personality, the study suggests Science

When Kathleen Morrill was 12, she decided she needed a puppy. Not any puppy – a liter-sized papillon with a black nose and shaggy, lively ears. When her parents resisted, “I turned on the plumbing,” laughs Morrill, now a graduate of the University of Massachusetts, Worcester. And so the family ended up with their first dog – a two-month-old puppy she named Todd.

Todd is registered with the American Kennel Club (AKC), whose website describes his breed as “curious” and “friendly” with a “hard constitution”. But the puppy was shy and afraid of strangers, and as he got older, he developed the anxiety of separation. When Morrill’s family got another papillon, Rosie, a year later, she was completely different: brave, open, and adored to all people. “Breed can be important,” says Morrill, “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 her colleagues show that almost none of the behaviors we associate with dog breeds – from cute Labradors to bitter pit bulls – are hard. Apart from a few ancient features, the environment seems to play a much bigger role than pedigrees.

“It’s a big step forward in the way we think about dog behavior,” said Elaine Ostrander, an expert in canine genetics at the U.S. National Institute on Human Genome Research who was not involved. “No breed has any special traits.”

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

Previous work has revealed some genetic relationships between breed and behavior, but observed average breed values ​​rather than comparing individual dogs. So Morrill and her colleagues used their lab’s own database, Darwin’s Ark, which since 2015 has collected survey and genetic data on thousands of dogs across the United States. Owners answer more than 100 questions – ranging from how friendly their puppies are to strangers to whether they like to hunt squirrels – and then send a swab of their cheeks for DNA sequencing.

In the largest study of its kind, the team compared genetic data and survey data on nearly 2,000 dogs – most of whom had the entire genome sequenced – and the results of an additional 16,000 dogs. Puppies included mixed breeds and purebred breeds, and 128 breeds were represented.

When it comes to physical traits, such as size and flexible ears, genes have ruled. At least 80% of a dog’s appearance may be related to his DNA, the team found.

Behavior was another story. Less than a quarter of the difference in personality from dog to dog can be explained by genetics. Some behaviors, such as taking objects and human sociability, were more hereditary. Researchers speculate that the extraction may have helped the ancestors of wolf dogs in hunting and that people probably opted for friendly dogs in the early days of domestication.

But most behaviors did not have a strong genetic component, including playfulness near other dogs and (yes, it was in the survey) whether the dog circled 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 oversaw the study.

And when it comes to dog breeds, the personality differed greatly within the same pedigree. Labradors can be kind or unwavering. German shepherds, easy to train – or impossibly stubborn. Only 9%, on average, of the difference in personality between puppies was related to their breed, the team reported today in Science.

Some breeds have even defied their stereotypes. Pit bulls, for example, (although not an official AKC breed) have not been more aggressive than other dogs, despite their reputation in some dangerous circles. The results, Karlsson says, “coincide with what the canine world has told us” – that the behavior of these animals is shaped by their environment, not their breed.


No breed has any special trait.

  • Elaine Ostrander
  • American National Institute for Human Genome Research

Conclusion, she says: if you are looking for a dog with a specific personality, “you should not buy from a catalog. Every dog ​​is an individual. ” (The website the team set up shows how hard it is to know what you might get.)

Personalities aside, most breeds it seems they have a special look – probably because breeding is much easier than breeding because of behavior, says Adam Boyko, a Cornell University dog ​​genetics expert who was not involved. Behavior breeding could also have drawbacks, he says. “Anything that changes the brain pattern so much is likely to have negative effects on other areas.”

Yet, after decades of treating, exhibiting and evaluating countless breeds, the AKC’s chief veterinarian, Jerry Klein, is challenging the study’s conclusions. “I think most dogs meet the personality standard of their breed,” he says. Supposedly older breeds, he says, like Tibetan Mastiffs and Baseni – several of which were included in the study – may have more stubborn characters because they have been there longer.

Klein also argues that if researchers look beyond the breed to classes of dogs – such as sport dogs (which include various spaniels) and fragrant hounds (such as bassets and beagles) – they would find that their behaviors are more similar to each other. than they are to other dogs. “It’s not as simple as just breeds.”

If nothing else, Morrill hopes this work will open up new insights into the dog’s personality. The team found 11 new behavioral-related DNA regions, including one for howling and the other for sociability; in humans, these regions are associated with language, or long-term memory. That could one day help scientists treat neurological conditions in both puppies and humans, she says.

Todd died a few months ago, just after his 15th birthday. He became more confident as he grew, to which Morrill attributes a soothing presence to Rosie. His personality was not tied to his breed – and it wasn’t fixed either, she says. “Dogs, like humans, can change over time.”

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