Everyone knows Pit Bulls and Rottweilers are aggressive, while Labradors are affectionate.
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Except no.
According to a new study published Thursday in the prestigious journal Science, these dog breed stereotypes are largely unfounded.
Many behavioral traits may well be inherited. But race only partially predicts most behaviors — or even not at all for some traits, like affection or anger.
“Genetics play a role in the personality of any individual dog, but breed does not predict these traits effectively,” said Elinor Karlsson, one of the authors of the work, which involved more than 2,000 dogs and counting. than 200,000 responses from owners.
“What we’ve shown is that the defining criteria for a golden retriever are its physical characteristics — the shape of its ears, the color and quality of its coat, its size. But not if he is affectionate,” she added.
However, such stereotypes sometimes find their way into the law, such as the pit bull ban in the UK and many US cities.
The researchers sequenced the DNA of 2,155 pedigree or crossbred dogs to find common genetic variations that could help predict their behavior. They combined these results with answers to questions from 18,385 dog owners.
The site used is called Darwin’s Ark, and represents a free access database bringing together the information provided by owners on the behavior of their animal.
The researchers took into account in their analyzes the stereotypes possibly affecting the answers.
They established fixed definitions for certain behaviors, such as obedience, sociability, or interest in toys. Physical traits were also studied.
The scientists finally found 11 places in the genome associated with behavioral differences, including obedience, the ability to retrieve an object, or even howling.
In these cases, breed did play a role: beagles and bloodhounds tend to howl more, border collies are more obedient than shiba inus.
But the study nevertheless showed that there were exceptions each time.
So even though Labradors were the least likely to howl, 8% of them still did. And if 90% of greyhounds did not bury their toy, 3% did so frequently.
Moreover, by observing the answers to several questions concerning the possible aggressive reactions of dogs, “we did not see any effect of the breed”, explained Elinor Karlsson.
In total, race explained only 9% of behavioral variations. Age thus better predicted certain traits, such as having fun with a toy.
Physical traits could be five times better predicted by race than behavior.
Prior to the 1800s, dogs were primarily bred for their roles in hunting, to guard the home or herds.
But the concept of “the modern canine breed, emphasizing physical ideals and purity of lineage, is a Victorian invention,” the study points out.
Dogs within a breed may behave differently, with some having inherited genetic variations from their ancestors, and others not.
Interesting fact: sociability towards humans is very hereditary in dogs, although not dependent on breed.
Researchers have located a spot in canine DNA that could explain 4% of differences in sociability between individuals. And this place corresponds to the one, in the human genome, responsible for the formation of long memory.
“It could be that understanding sociability towards humans in dogs helps to understand how the brain develops and learns,” said Kathleen Morrill, lead author of the study, at a press conference.
The next step, according to her, would be to look at behavioral disorders in dogs, and their possible links with those of humans.
“You can’t ask a dog what their problems are, their thoughts, their anxieties, but they are known to live rich emotional lives and suffer from disorders that manifest themselves in their behavior,” explained the researcher.
Understanding the links between race and behavior could thus help determine which genes are responsible for certain psychiatric disorders in humans, such as obsessive-compulsive disorder.