Dog Breed Doesn’t Dictate Personality

By Christina Hooton

Does your dog love strangers, or does it cower in fear at the slightest noise? Does it love to play fetch, or does it prefer to stand guard? We often attribute these personality traits to a dog’s breed, but according to a new study from scientists at UMass Chan Medical School and the Broad Institute, breed may not be as strong an indicator of a dog’s personality as we once thought. Experts agree that a dog’s behavior results from many factors, including genes, development, socialization, and environment.

An Ancient Bond

Ancient wolves evolved into the modern dogs we call our best friends today. It all started when these prehistoric canines began relying on ancient humans for food and shelter. Humans learned they could rely on these proven predators for help with hunting and protection. Over time, the wolf evolved to be less fearful of humans and more docile. Certain species began to specialize in tasks like herding, retrieving, and providing protection.

It wasn’t until much later that humans began breeding dogs for looks instead of specific jobs. In the 1880s, the American Kennel Club was formed and developed strict guidelines that defined the physical traits and personality of a dog’s breed. These guidelines are still viewed as truths today.

Shedding New Light on Breed

To determine if breed truly impacts behavior, UMass and Broad Institute scientists surveyed over 18,000 dog owners, asking them over 100 questions about their dogs’ sizes, lifestyles, and more. The proportion of purebreds versus mixed-breed dogs was half and half, a ratio representative of the real world. Saliva and blood samples were collected to DNA sequence 2,155 of the dogs in the survey and better understand their genetics.

“The genetics allowed us to piece apart the puzzle — especially for mixed-breed dogs that have multiple backgrounds — of where the DNA differs the most between dogs that differ in their traits,” said Kathleen Morrill, a dog geneticist at the University of Massachusetts Chan Medical School, in a Scientific American article.

Study authors identified 11 genetic regions strongly tied to a dog’s behavior. These behavioral regions were not found to be specific to any one of the 78 breeds studied. They concluded that only nine percent of the behavioral variation among different types of dogs could be explained by breed. Some traits seemed more closely related to breed, but these were service functions such as hunting or herding, behaviors that have been reinforced for thousands of years.

Breeding Understanding

Certain dog breeds get a bad rap. For example, pit bulls, thought to be much more aggressive, are less likely to be adopted from a shelter. Some breeds are outlawed or regulated by some U.S. jurisdictions. Knowing that a dog’s behavior is not necessarily predetermined by breed may help to change some of these negative preconceptions and give certain breeds a new opportunity to find loving homes.