Playful, mischievous, lovable, or lazy, canine personalities seem to span a spectrum as broad as found in humans. Indeed, one of the first questions that every potential dog owner asks is how a specific breed’s quirks will fit into what they are looking for in a companion. Websites, books, and even dog breeders themselves happily encourage owners to select a breed with a personality that matches the desired behavior. For example, Golden Retrievers are a perfect fit for someone that wants a playful and loving family dog, while Corgis are curious, enthusiastic, and adventurous.

These “breed-specific traits” drive demand for certain dogs over others. For example, breed personalities often influence which dogs are adopted first, which jobs they are qualified for, and even which are allowed to live in apartment and condo buildings. Additionally, the way that the dogs are trained and treated is often prejudiced by these stereotyped traits. However, most dog trainers will happily tell you about the “outliers”: the loveable pitbull that wouldn’t hurt a fly, the retriever that refuses to play fetch, or the lazy border collie that would rather hang out on the couch than run in the yard. However, a new study is arguing that almost none of the behaviors that we associate with dog breeds are actually responsible for these traits.
The new research paper, led by Kathleen Morrill and published in the April 29th, 2022 issue of Science, examined over 2000 purebred and mixed-breed dogs to map physical and behavioral traits to DNA sequences. The team additionally collected survey data from over 16,000 canines. Unsurprisingly, this combined data clearly shows that physical traits in dog breeds are tied to specific sequences of DNA. However, a breed’s genetic code has much less of an impact on the personality than expected!
Dog owners completed 12 short surveys on both physical and behavioral traits. The behavioral questions looked at personality traits such as human and dog sociability, interest in toys, and impulse control. These traits were then compared to the physical size of a dog, which is strongly determined by the genetics of the breed. Unsurprisingly, this analysis revealed that physical traits are exceptionally heritable, with size, fur length, ear shape and more being over 85% heritable. Similarly, certain behavioral traits were also tightly linked within breeds. For example, retrieving objects and human sociability are more heritable than other traits, and are tightly linked to certain breeds.

However, many behaviors show high variability within breeds. This suggests that although genetics might affect the likelihood of a particular personality trait it is not enough to predict an individual dog’s behavior. The researchers demonstrated this by comparing the behavioral data for a breed against randomly selected dogs. If a trait was highly correlated to a breed, this analysis would show that the breed more commonly (or less frequently, depending on the trait) demonstrates the behavior compared to a random dog. However, the majority of breeds show little correlation to motor patterns and behavioral tendencies. The authors conclude that breeds are very poor predictors of an individual dog’s behavior.
It’s important to note that this study does not say that a breed has no impact on a dog’s personality. Certain highly-heritable traits, like how easy a dog can be trained, can be estimated based on the dog’s ancestry. Similarly, physical traits are highly heritable and breed-specific. At the same time, less breed-differentiated traits, like how easily a dog is provoked, are almost fully independent. In the end, the researchers concluded that only 9 percent of the variation in behavior can be linked to a dog’s breed.
Understanding that a dog’s breed does not determine its personality could have a significant impact in the future. For example, perceptions of breeds can influence how quickly a dog is adopted, how an owner trains the dog, and even the perceived intelligence. In the end, what really matters is the individual dog and not the breed. After all, all dogs are good dogs!