That’s an AGGRESSIVE Breed?

Debunking the Myth
That Breed Predicts Aggression  
  

Many people believe certain dog breeds are inherently aggressive, but research increasingly shows this is a misconception. While breed may influence general tendencies, it is far from the only, or strongest, predictor of aggressive behaviour. Being descendants of inherently aggressive animals (the wolf), aggressivity is a complex trait in which different genes, environmental factors (e.g., maternal effect, sex, age, neuter status, litter size and pet-paren personality) and their interactions play a pivotal role.

As a veterinarian, I’m constantly reminded how unpredictable dogs (and all animals including humans) can be. In my experience which aligns with evidence-based research, a well-socialised dog tends to have better mental health than one that missed pivotal experiences as a puppy, bred in a puppy farm, or exposed to early-life trauma. Interestingly, the same Nature versus Nurture debate we see in humans applies to dogs as well.

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Attacks are more strongly influenced by socialisation, training, environment, health, and guardian behaviour than by breed alone.

Australian Veterinary Association

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Placing rigid restrictions on specific breeds is both scientifically flawed and ethically questionable. Breed identification is often unreliable (even with current DNA testing), and prejudice, or “breedism”, has no place in a community built on support, love, and inclusion.

In Australia, animal welfare bodies like the RSPCA (The Royal Society for the Prevention of Cruelty to Animals) argue that breed-specific legislation is based on confounding assumptions: that certain breeds are inherently dangerous and that appearance reliably predicts risk. Temperament tests consistently show that “restricted breeds” do not differ significantly in behaviour from other dogs. The RSPCA maintains that each dog should be assessed individually, rather than judged by breed.

Similarly, the Australian Veterinary Association critiques breed bans in its report Dangerous Dogs - A Sensible Solution, noting that such bans rarely reduce dog attacks. Instead, attacks are more strongly influenced by socialisation, training, environment, health, and guardian behaviour than by breed alone. For example, New South Wales statistics show American Staffordshire Terriers appear most often in dog attack reports, but breed identification was frequently unreliable, deliberately misleading or not reported at all. This data lacked breed verification and any commentary regarding other influencing factors like individual dog temperament, pet parent behaviour and whether the dog is desexed.

Behavioural science confirms: aggression is multi-factorial. Genetics play a role, but early-life experiences, socialisation, training, environment, and how humans interact with their dogs matter enormously. Recent international studies estimate that breed accounts for only 10-40% of behavioural variation.

Decisions based solely on breed can result in prejudice, exclusion and unnecessary euthanasia, leaving genuinely dangerous dogs unidentified. Cross-breeds and mixed ancestry further complicate the picture, and relying on appearance alone risks overlooking or misjudging a dog’s behaviour.

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What This Means for Pet Parents  
  

 Don’t assume aggression, or passivity, based on assumed breed alone.
Prioritise socialisation, positive training, predictable environments, and attentive care.
 When choosing a dog, consider temperament, history, energy levels, and household fit over breed.
  Support evidence-based policies over breed bans. Education campaigns, responsible breeding, good guardian behaviour, leash laws, and safe containment are far more effective.
 If your dog shows aggression, it often stems from fear or stress. As a pet parent, it’s your responsibility to understand your dog’s limitations and ensure environments are safe and suitable for them. Do not place this burden of responsibility on others.