Whether a thunderclap drives your dog to cower behind the couch or leaves it unfazed may be determined in part by genetics. In the June issue of GENETICS, Ilska et al. analyze genetic contributors to canine personality traits—such as fear of loud noises—using owners’ reports of their pets’ behavior.

The researchers chose this survey-based method in place of standardized behavior testing both to create a large body of data and to eliminate any influence of a foreign testing environment on the dogs’ behavior. They measured 12 different traits, from trainability to tendency to bark, using a 101-item questionnaire called the Canine Behavioral Assessment and Research Questionnaire (C-BARQ) that was originally designed to screen potential guide dogs. Then they looked for relationships between these traits and aspects of the dogs’ pedigrees and genotypes.

Of these traits, the most heritable were fear of noises and ability to play fetch. Perhaps surprisingly, many of the genetic factors linked to fetching ability were not related to other aspects of trainability. Aggression toward strangers and other dogs was also heritable, but aggression toward owners was not, likely because humans have placed strong selective pressure on dogs to be loyal and gentle toward their owners, leading to low genetic variance. Some traits were also related to each other—trainability had an inverse relationship with “unusual behavior,” a finding that probably wouldn’t shock most dog owners.

Some of the variants associated with the personality traits were located near genes with known neurological functions. For example, dogs that were prone to agitation often carried a variant near the gene for tyrosine hydroxylase, which is involved in the synthesis of the neurotransmitter dopamine. In humans, dopamine dysfunction is implicated in psychological conditions such as attention deficit-hyperactivity disorder, and some variants of the tyrosine hydroxylase gene are associated with the tendency to experience negative emotions and excitability—both traits related to impulsivity.

Because the study was conducted only on Labrador Retrievers in the United Kingdom, the authors caution that other dog breeds may differ in how heritable different personality traits are. But in any case, just like human personalities, it seems that dog personalities have a strong genetic component. So if your dog stares at you blankly next time you throw it a ball, don’t succumb to frustration—fetching just may not be in its genes.


Ilska, J.; Haskell, M.; Blott, S.; Sánchez-Molano, E.; Polgar, Z.; Lofgren, S.; Clements, D.; Wiener, P. Genetic Characterisation of Dog Personality Traits.
GENETICS, 206(2), 1101-1111.
DOI: 10.1534/genetics.116.192674


Nicole Haloupek is a freelance science writer and a recent graduate of UC Berkeley's molecular and cell biology PhD program.

View all posts by Nicole Haloupek »