Study Finds Dog Behavior is Not Predominantly Determined by Breed

Dr. Elinor Karlsson of the University of Massachusetts Chan Medical School, a co-author of the study published in the journal Science, highlighted the significant variation in behavior within each breed. "Even if the average is different, you’ve still got a really good chance of getting a dog that doesn’t match what people say that breed is supposed to be," she stated.

The study analyzed survey responses about the physical traits and behaviors of 18,385 pet dogs, nearly half of which were purebred. Genetic data was also reviewed for 2,155 of these dogs. The results showed that only about 9% of behavioral variation in purebred dogs could be attributed to their breed.

While some behaviors were indeed linked to specific breeds—such as howling being more common among beagles and pit bulls and retrievers showing greater sociability with humans—no behavior was found to be exclusive to a single breed. For instance, herding breeds exhibited greater compliance but varied widely in behavior among individuals.

To further investigate the genetic basis for these associations, the researchers examined mixed-breed dogs with varying degrees of ancestry from specific breeds. Results indicated that some traits, like an affinity for water typically associated with Labrador retrievers, did not correlate with human sociability, suggesting that environmental factors or owner perceptions may play a more significant role.

The study concluded that prospective dog owners should focus less on breed stereotypes and more on the individual dog in front of them. Daniel Mills, a professor at the University of Lincoln who was not involved in the study, noted that while genetics can inform population behaviors, they often tell little about individual dogs. He emphasized that aggressive behaviors are likely influenced more by an animal's environment and experiences than by genetics alone.

Additionally, a separate study published in Scientific Reports found that different dog breeds have notably different life expectancies. Analyzing 30,563 dog death records in the UK from 2016 to 2020, researchers observed that Jack Russell terriers tend to live an average of 12.72 years, while brachycephalic breeds like French bulldogs had a much shorter life expectancy of 4.53 years due to health issues linked to their physical traits. Justine Shotton, president of the British Veterinary Association, stated that these findings emphasize the need for potential dog owners to prioritize health over appearance when choosing a breed.