Everyone knows pit bulls and rottweilers are aggressive, while labradors are affectionate. Except no.
According to a new study published Thursday in the prestigious journal Science, these stereotypes of dog breeds are largely unfounded.
Many traits of behavior can be inherited. But race only partially predicts most behaviors, or even not for some traits, such as affection or anger.
“Genetics play a role in the personality of any individual dog, but the breed does not predict these traits effectively.“, explained Elinor Karlsson, one of the authors of this work, which involved more than 2,000 dogs and more than 200,000 responses from owners.
“What we have shown is that the criteria that define 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“, added.
These stereotypes are sometimes found in the law, however, such as banning pit bulls 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 an open access database that collects information provided by owners about their pet’s behavior.
The researchers took into account in their analysis the stereotypes that possibly affected the responses.
They established fixed definitions for certain behaviors, such as obedience, sociability, or interest in toys. Physical traits were also studied.
Scientists eventually found 11 sites in the genome associated with differences in behavior, including obedience, the ability to retrieve an object, or howls.
In these cases, the breed did play a role: beagles and bloodhounds tend to howl more, border collies are more obedient than shiba inus.
However, the study showed that there were exceptions every time.
Thus, although Labradors were the least likely to howl, 8% still did. And if 90% of greyhounds did not bury their toy, 3% did so frequently.
Also, look at the answers to several questions about possible aggressive reactions in dogs. “we saw no effect of race“, explained Elinor Karlsson.
In total, race accounts for only 9% of behavioral variations. Therefore, age better predicted certain traits, such as having fun with a toy.
Physical traits could be five times better predicted by race than by behavior.
Prior to the 1800s, dogs were bred primarily for hunting purposes, to protect the home or herds.
But the concept “The modern canine breed, which emphasizes the physical ideals and purity of the lineage, is a Victorian invention.“, emphasizes the study.
Dogs of one breed may behave differently, some of them have inherited genetic variations from their ancestors and some have not.
Interesting fact: sociability towards humans is very hereditary in dogs, although it does not depend on the breed.
Researchers have located a point in canine DNA that could explain 4% of differences in sociability between individuals. And this place corresponds to that, in the human genome, responsible for the formation of long memory.
“Understanding the sociability of humans in dogs can help us understand how the brain develops and learns.“Kathleen Morrill, the study’s lead author, told a news conference.
The next step, she said, would be to look at the behavioral disorders of dogs and their possible links with humans.
“One cannot ask a dog what his problems, thoughts, anxieties are, but he is known to live rich emotional lives and suffer from disorders that appear in his behavior.“, explained the researcher.
Understanding the links between race and behavior could help determine which genes are responsible for certain psychiatric disorders in humans, such as obsessive-compulsive disorder.