A new study reveals that while short-nosed breeds have innate behavioral traits, their environment and upbringing play a far more significant role than owners might think.
French Bulldogs, Pugs, and other short-nosed (brachycephalic) breeds have captured the hearts of millions, consistently topping popularity charts worldwide. Their baby-like faces and expressive eyes are undeniably charming, and owners often describe them as perfect companions: interactive, affectionate, and playful. But this popularity comes with a well-documented dark side, as these breeds often suffer from a host of health issues, including chronic breathing difficulties, skin allergies, and eye problems.
This raises a compelling question for scientists and dog lovers alike: What makes these dogs so irresistible that owners are willing to overlook significant health concerns? Beyond their cute appearance, many believe their behavior is the key. But is that calm, friendly demeanor an inherent part of being a Pug, or is something else at play? A groundbreaking study from ethologists at Eötvös Loránd University (ELTE) in Hungary decided to untangle this complex web of nature versus nurture.
Researchers embarked on a mission to discover whether the behavioral traits associated with flat-faced dogs truly stem from their unique head shape or if they are a product of how they are raised. The findings suggest that while genetics play a role, factors like small body size, lack of training, and a tendency for owners to pamper them have a profound, and often negative, impact on their behavior.
First Impressions vs. Deeper Truths
To get to the bottom of this, the ELTE researchers analyzed questionnaire data from over 5,000 purebred dogs in Germany. They compared four key personality traits and four common behavioral problems, examining them in relation to the dog’s head shape, body size, living conditions, and even the owner’s characteristics.
At first glance, the data seemed to confirm some stereotypes. When looking only at head shape, short-nosed dogs did indeed appear calmer and bolder than their long-nosed counterparts. However, this initial analysis also highlighted less desirable traits. Owners reported that these breeds were harder to train, were more reluctant to come back when called, and tended to overreact when guests arrived at the house. This created a confusing picture: were they calm companions or poorly trained troublemakers?
The answer, the researchers found, was hidden in the details of their daily lives. The study revealed a distinct profile for the typical short-nosed dog and its owner. These dogs are more likely to be small, young, unneutered, and kept exclusively indoors. They are also more frequently allowed on the bed and receive less formal training than other dogs. Their owners are often young, single women who have never owned a dog before and chose the breed primarily for companionship.
Each of these factors can independently influence a dog’s behavior. For example, it’s well-known that smaller dogs are often treated differently and may be more prone to jumping on people. Likewise, experienced owners typically have better-trained dogs, and older dogs are naturally calmer. The lifestyle of being a pampered, indoor companion was a massive confounding variable that was potentially masking the true effect of head shape.
Untangling the Influence of Nature and Nurture
Armed with this knowledge, the researchers employed more sophisticated statistical analyses to control for these environmental and demographic factors. They wanted to isolate the behavioral traits that were directly linked to head shape from those that were a result of pampering, small size, or lack of training. The results were fascinating and painted a much clearer picture.
One of the most significant findings was that the perceived low trainability of short-nosed dogs had little to do with their flat faces. “We found that the low trainability of short-nosed dogs is mainly due to their small body size and lack of training — not their head shape,” explained Borbála Turcsán, a researcher on the study. Once the analysis accounted for these influences, the difference in trainability between head shapes vanished.
However, the study also confirmed that some behaviors are indeed innate to these breeds. Calmness, boldness, and a poor recall response were all directly connected to a short-headed physique, remaining significant even after controlling for all other factors.
Perhaps most surprisingly, the analysis uncovered hidden positive traits. Once the effects of being spoiled and undertrained were statistically removed, it turned out that short-nosed dogs are genetically less likely to engage in problem behaviors like jumping on people, pulling on the leash, or reacting excessively to guests. The reason owners often experience these problems is that the dogs’ good innate tendencies are being overridden by a lack of structure and training.
On the flip side, the research did identify an innate challenge: short-nosed dogs are inherently less friendly toward other dogs. This effect is often masked in puppyhood, as younger dogs are generally more sociable, but it’s a genetic predisposition owners should be aware of.
Why Does Head Shape Matter?
The direct link between head shape and behavior begs the question: why? The researchers offer a few compelling possibilities. “The brains of short-nosed dogs are more rounded, and their patterns of brain activity differ from those of other breeds, so it’s easy to imagine that their brains regulate behavior differently,” notes Enikő Kubinyi, head of the Department of Ethology at ELTE. The very structure of their skull, a result of selective breeding, has reshaped their brain, which could logically lead to different behavioral outputs.
There is also a more sobering hypothesis related to their health. The study suggests that the breathing difficulties, chronic pain, and musculoskeletal issues common in these breeds might cause them to move less and seek comfort more often. What an owner interprets as a desirable “calm” demeanor could, in some cases, be a sign of physical distress. Their perceived neediness and vulnerability might even be part of their appeal, fostering a deep sense of protectiveness in their owners.
The Takeaway for Every Owner
The ultimate message from this comprehensive study is one of balance. Short-nosed dogs possess a unique genetic blueprint that includes some wonderful traits for companionship, such as calmness and low reactivity. However, these positive qualities are not guaranteed to shine through. They can be easily obscured by the negative consequences of an upbringing that prioritizes pampering over training.
While a Pug might be genetically less inclined to pull on the leash, it will never learn to walk politely if it’s never taught how. The study underscores a universal truth for all dog owners, regardless of breed: good traits need structure to emerge. For the millions who adore their flat-faced friends, the path to a well-behaved companion isn’t just about choosing the right breed—it’s about providing consistent training and guidance to help their best nature flourish.
