The American Kennel Club website describes the ideal shape and temperament of 204 dog breeds, from the Affenpinscher (“loyal, inquisitive, and famously amusing”) to the Yorkshire Terrier (“feisty, courageous, and sometimes opinionated”). The idea that certain breeds reliably exhibit different behaviors is baked into dog shows, obedience training, and canine DNA testing, not to mention laws targeting breeds deemed prone to aggression.
However, a detailed new study of canine behavior and genetics suggests that breed is actually of little value in predicting an individual animal’s behavior or behavior.
After collecting extensive data from the owners of more than 18,000 dogs and sequencing the DNA of more than 2,100 of these pets, the researchers found strikingly few associations between breed and most behavioral traits.
Yes, Labrador and Golden Retriever owners were slightly more likely to place their puppies in the top 25% for “human sociability” than random dog owners. And yes, hunting breed dogs were more likely to score higher on “leadability,” or the ease with which they respond to human commands. But associations like this were neither strong nor enduring.
In fact, breed explains no more than 9% of the behavioral variation among the dogs in the study, said study co-author Elinor Karlsson, a geneticist at the University of Massachusetts Chan Medical School. A dog’s age and sex were often far better predictors of its behavior, and for some traits – most notably aggression – breed made no difference at all.
The findings were published Thursday in the journal Science.
Each of the roughly 1 billion dogs currently roaming the planet belongs to the same species – Canis familiaris. They split off from wolves about 10,000 years ago, which wasn’t long enough to accumulate that much genetic diversity. (Mammals typically evolve over hundreds of thousands of years.)
The concept of the modern dog breed was only invented about 160 years ago, in what the authors call “a blink of an eye in evolutionary history.” Few genetic differences are responsible for the striking differences in the dogs’ shape and appearance.
Physical traits are highly heritable; behavioral characteristics, less. These are determined by a complex mix of genetic and environmental factors in which breed plays only a small, often insignificant, role.
“What a dog looks like doesn’t really tell you how a dog behaves,” said Marjie Alonso, executive director of International Assn. of Animal Behavior Consultants and co-author of the study.
The team created an open database, Darwin’s Ark, to collect information about individual dogs. Owners were asked to answer more than 100 questions about their dog’s appearance, behavior and personality.
The result was a data set that was a good reflection of the US pet population. Almost half (49.2%) of the participants identified their dogs as purebred, with the proportion of breeds represented roughly corresponding to US dog ownership.
The owners of purebred dogs tended to describe their pets’ behavior in a way that conformed to the breed’s stereotypes, the authors wrote. This raised the possibility that owners’ assessments were – consciously or unconsciously – influenced by the reputation of their dog breed.
Fortunately, the remaining dogs in the study were mutts, whose ambiguous parentage left their owners comparatively free from preconceived notions about their background or behavior. They served as a kind of control group.
Researchers found that Golden Retriever owners tended to say their pets weren’t afraid of strangers, a description that fits the breed’s outgoing reputation. However, owners of mutts with some Golden Retriever ancestry did not describe their pets as more fearless of strangers than owners of mutts with no Golden Retriever DNA.
Likewise, Labrador Retriever owners have tended to say that their pets are social with people, in line with the stereotype that the breed is friendly and outgoing. But mutt owners with a Labrador Retriever in their bloodlines were no more likely to name their dogs socially to humans than mutt owners without that heritage.
If breed were a strong predictor of behavior, it stands to reason that the traits of those breeds would have manifested themselves to some degree in the mutts with those breeds’ DNA.
Even among purebred dogs, genetics were a much more reliable indicator of how an individual dog looked than how they behaved.
“Physical traits are super heritable,” Karlsson said. But when it comes to behavior, “race is a very poor predictor. It is not an accurate method of predicting an individual dog’s behavior.”
But there have been some trends in certain traits like docility and a dog’s propensity to grab and bite toys, she added.
Border Collies, for example, tend to be more docile than the average dog. Choosing a border collie as a pet may increase your chances of getting a docile animal, but it doesn’t guarantee that the specific dog you bring home will be naturally inclined to follow your commands.
In the millennia before the Victorian obsession with dog breeding began, people primarily categorized dogs based on the jobs they did best. Some puppies were good at herding, others at hunting or guarding. A now-extinct type known as the “rotisserie” or kitchen dog was raised to run on a sort of dog-sized hamster wheel that spun skewers over flames, said Katherine Grier, a retired University of Delaware history professor and author of the book Pets in America : A story”.
In The Invention of the Modern Dog: Breed and Blood in Victorian Britain, authors Michael Worboys, Julie-Marie Strange, and Neil Pemberton compared the difference between pre- and post-breed dogs to colors in a rainbow and in a coloring book, Chips. Initially, there were a few broad dog types with a lot of overlap between them. Breeding took that barking rainbow and broke it down into isolated, well-defined units.
The American Kennel Club maintains the largest registry of purebred dogs in the United States, along with detailed descriptions for each breed standard, including personality traits. (The Chow Chow is “dignified, bright, earnest”; the Chihuahua is “charming, graceful, perky.”)
The club said it believed the study’s data were robust, but disagreed with the authors’ conclusions.
“Racial behavior was not created with race formation 100 years ago. It was created based on working behaviors selected over centuries – and before individual breeds separated,” said Chief Veterinarian Dr. Jerry Klein in a statement. “Therefore, attempting to separate individual breeds on the basis of their behavior would not be successful without subdividing them into select populations of ancestral herding dogs, gun dogs, etc.”
Historians of dog breeding counter that breeders’ preference for certain physical traits has often come at the expense of original behaviors over the years. Dog breed is largely defined by an animal’s appearance, and “when you breed for appearance, you can lose behaviors,” Grier said.
When it comes to dog behavior, genes “do have an effect, but it’s less than the effect that genes have on physical traits,” said Danika Bannasch, an animal genetics specialist at UC Davis who was not involved in the study was. “This is the most comprehensive study of its kind on genes and behavior and is sure to make many people stop and think a little differently about dogs.”
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https://www.latimes.com/science/story/2022-04-28/genetic-study-says-stereotypes-about-dog-breeds-are-wrong Genetic study challenges stereotypes about dog breeds