FRIDAY, April 29, 2022 (HealthDay News) — Over the past two centuries, humans have been herding dogs to cater to specific physical characteristics – to make Golden Retrievers fluffy, to make Rottweilers muscular, or to make Chihuahuas tiny.

Dog fanciers thought they also passed on specific behavioral traits within breeds, giving rise to certain stereotypes – Golden Retrievers are affectionate and fun-loving, Rottweilers are confident and aggressive, and Chihuahuas are cheerful and excitable.

But a dog’s breed could actually account for as little as 9% of their behavioral traits, according to a new genetic study.

Instead, all dogs seem to share a wide range of behaviors developed over the 10,000 years they’ve spent with humans, and especially over the past two millennia in which they’ve been given tasks. specific ones like guarding or breeding, the researchers said.

Modern breeding has succeeded in altering the appearance of dogs, but not necessarily the behavior of individual dogs, the study concluded.

“We found things like German Shorthaired Pointers were slightly more likely to point, or Golden Retrievers were slightly more likely to retrieve or Siberian Huskies to howl than the general dog population,” the co-author said. study author, Kathryn Lord. She is a canine evolutionary biologist and postdoctoral researcher at the University of Massachusetts in Worcester, Mass.

“But because these behaviors predate breeds, we also see them in other breeds and other dogs that aren’t exclusive to those particular breeds,” Lord said. “So I’ve known Labradors that howled and Papillons that pointed and Greyhounds that recovered, and Retrievers that didn’t.”

In particular, the researchers found that aggressiveness – the ease with which a dog is provoked by frightening or uncomfortable things – is almost completely misinformed by the breed.

“When we looked at this factor that we call the ‘agonistic threshold,’ which included many questions about how aggressive dogs reacted, we didn’t see an effect of racial ancestry on this particular factor,” said the principal researcher. Elinor Karlsson, professor of bioinformatics and integrative biology at the University of Massachusetts.

Aggression not related to race

Given this, legislation banning specific breeds deemed aggressive and dangerous “doesn’t seem to make much sense to us,” Karlsson said.

American Kennel Club (AKC) chief veterinarian Dr Jerry Klein agreed that the results “could definitely be useful in de-stigmatizing breeds classified as dangerous, which we do not recommend”.

According to Klein, “There are several factors, including but not limited to environment, nutrition, and socialization that can affect a dog’s behavior, and these factors must be taken into consideration because every dog ​​is different.”

However, the AKC won’t go so far as to accept that breed is meaningless for an individual dog’s behavior, Klein added.

“It is the position of the AKC that the breed informs general, instinctual behavior, and it is the reason why owners should consider behavioral tendencies before selecting a breed in order to make an informed and well-informed decision. that will lead to a happy, lifelong commitment to your dog,” he noted.

For this study, published on April 29 in the journal ScienceKarlsson and his colleagues sequenced the DNA of 2,155 dogs, including purebred dogs and mixed-breed mutts.

Investigators then compared this data with more than 18,000 surveys of pet owners from Darwin’s Ark, an open-source database of owner-reported canine traits and behaviors, to see if certain genetic traits matched types. specific driving.

“People are actually really good at telling us about their dog’s behavior,” Karlsson said. “They spend a lot of time looking at it. And if you ask them, they’ll tell you, and they’ll tell you very specifically.”

The researchers found that most behavioral traits can be inherited, but when they looked at mixed breed dogs they found that specific genetics did not always have a hold on an individual dog’s behavior.

Mutts showed that genes don’t always predict behavior

“Pops were actually the ideal type of dog to assess breed-behaviour links because among these pooches you will find dogs that are naturally mixed in their physical appearance, personality traits, disease risk, and DNA. “said lead researcher Kathleen Morrill, a graduate student at the University of Massachusetts.

For example, owners have reported that Beagles as a breed are known to howl more, Labrador Retrievers tend to be more social with humans, and Border Collies are more likely to respond to commands from a human.

“If it’s actually a genetic trait,” Karlsson explained, “then when we go to look at mixed-breed dogs, we should see that dogs that have more Beagle ancestry or more Bloodhound ancestry — let’s say a dog with 70% Beagle versus a dog with 30% Beagle – we should see that these dogs are also more likely to be howlers because it’s a genetic trait and they have more ancestry from that background.”

It wasn’t as clear as that.

For example, researchers found no significant effect of Labrador genetics on a mixed-breed pooch’s average inclination to be sociable with humans. On the other hand, the genetics of the Border Collie were associated with a tendency to follow directions from humans.

“We have to accept that our dogs are individuals. Just like our children, yes, they come from the same parents, but they are not identical,” Karlsson said.

“If you talk to someone who owns eight dogs of the same breed, they’ll tell you all the reasons why all of those dogs are different from each other. You see this huge diversity within each breed,” Karlsson added. . “And so even if the average is different, you still have a very good chance of getting a dog that’s not what people say this breed is supposed to be.”

“Dogs have been bred, in certain breeds sometimes over centuries, to exhibit specific characteristics and perform specific functions,” Klein said. “They are ‘hardwired’ to certain characteristics and behaviors. However, no two dogs are the same in personality and behavior.”

The American Kennel Club has more information on dog breeds.

SOURCES: Kathryn Lord, PhD, canine evolutionary biologist and postdoctoral researcher, University of Massachusetts Chan Medical School, Worcester, Mass. ; Elinor Karlsson, PhD, professor, bioinformatics and integrative biology, University of Massachusetts, Chan Medical School, Worcester, Mass.; Jerry Klein, DVM, Chief Veterinarian, American Kennel Club; Kathleen Morrill, PhD candidate, University of Massachusetts Chan Medical School, Worcester, Mass. ; ScienceApril 29, 2022, online