Comparison of behavioural tendencies between 'dangerous dogs' and other domestic dog breeds – evolutionary context and practical implications

Aggressive behaviour by dogs is a considerable social problem, but the
ability to predict which individuals may have increased aggressive
tendencies is very limited, restricting the development of efficient
preventive measures. There is a common perception that certain breeds are
more likely to exhibit aggressive behaviour, which has contributed to the
introduction of breed-specific legislation. The rationale for such
legislation explicitly assumes high heritability of this trait while also
implying relatively little variation within breeds; these assumptions are
largely untested. We compared behavioural tendencies between 8 breeds that
are subject to legislation in at least one country and 17 breeds that are
not subject to legislation using two validated psychometric tools: the Dog
Impulsivity Assessment Scale (DIAS), which scores elements of impulsivity,
including a tendency for aggressive behaviour, and Positive and Negative
Activation Scale (PANAS), which scores sensitivity to positive and
negative stimuli (which may trigger aggressive responses). We found that
the two groups of breeds do not differ significantly in the specific DIAS
factor relating to aggressive behaviour, “Aggression Threshold and
Response to Novelty”, or any other DIAS and PANAS factors. We found large
variation in all behavioural tendencies measured by both psychometric
scales within both groups and within each breed studied. Taken together,
our findings indicate that breed alone is not a reliable predictor of
individual behavioural tendencies, including those related to aggression,
and therefore breed-specific legislation is unlikely to be an effective
instrument for reducing risk.