Are you and your dog two of a kind? Science says yes.
If you’ve ever joked that your dog takes after you, science might just back you up. Studies show that our pups mirror our personalities more closely than we realize — from their energy levels to their anxieties. But while your dog may pick up on your mood, researchers are discovering that genetics, environment, and even the way we choose our dogs all play a role in shaping who they become.
In a study published in Applied Animal Behaviour Science, researchers asked pet parents to rate themselves on five major personality dimensions (as well as on corresponding personality traits of dogs). “The Big Five,” as they’re referred to in the psychology community, are:
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Neuroticism (a tendency towards feelings like anxiety and fear)
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Extraversion
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Conscientiousness
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Agreeableness
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Openness (level of creativity, curiosity and being open to new ideas)
Pet parents overwhelmingly responded that they share all five personality dimensions with their dogs. To be certain the results weren’t mere projection by pet parents, independent peers also assessed the dog and human duos. The independent peers also rated them as sharing all the dimensions, except for openness.
Why Is Dog Personality Linked to Human Personality? One explanation why dog behavior and personality is so intertwined with that of their humans is a tendency for people to select animals who complement their own lives. A calm human will often choose a calm dog, or an anxious person will adopt a frightened dog, for example, says Jenn Fiendish, a veterinary behavior technician who runs Happy Power Behavior and Training in Portland, Oregon. She believes people do this on a subconscious level.
Modern domestic dog breeds are only ~160 years old and are the result of selection for specific cosmetic traits. To investigate how genetics aligns with breed characteristics, Morrill et al. sequenced the DNA of more than 2000 purebred and mixed-breed dogs. These data, coupled with owner surveys, were used to map genes associated with behavioral and physical traits. Although many physical traits were associated with breeds, behavior was much more variable among individual dogs. In general, physical trait heritability was a greater predictor of breed but was not necessarily a predictor of breed ancestry in mutts. Among behavioral traits, biddability—how well dogs respond to human direction—was the most heritable by breed but varied significantly among individual dogs. Thus, dog breed is generally a poor predictor of individual behavior and should not be used to inform decisions relating to selection of a pet dog.
A genetic study of 2,155 purebred and mixed-breed dogs combined with 18,385 owner surveys has challenged existing notions about dog breed stereotypes and personality types. The study identified 11 locations along the canine genome that were strongly associated with behavior, none of which were specific for breed, suggesting that these personality traits predate modern canine breeding by humans.
Some initial findings from the lab include the discovery of neurological differences in dog breeds, including that premodern dogs tend to have a larger amygdala — the part of the brain that controls emotional processing and memory. Such heightened environmental-monitoring skills would come in handy for dogs deciding which humans to steal scraps from and which to avoid.
Modern dogs have a bigger neocortex — the part of the brain that controls motor function, perception, and reasoning. It may play a part in modern dogs’ increased behavioral flexibility, or ability to adapt to new environments.
Hecht’s lab connects personality and skill differences in dogs to six different parts of the brain: the regions controlling drive and reward; olfaction and taste; spatial navigation; social communication and coordination; fight or flight; and olfaction and vision. While breeds we see in our homes today share similarities in these pathways, Hecht’s research suggests the traits can be attributed more to selective breeding than ancestral DNA.
The factors with largest impact on personality were Role (11 traits) and sex-neuter status (eight traits). Exercise levels and coat color were also associated with several traits (five and four traits, respectively). Health status, housing, and age were associated with the fewest traits (2, 2, and 1, respectively).
When the dog genome was sequenced in 2005, scientists thought they would quickly be able to pin down the genes that give every breed its hallmark personality. But they found so much variation even within a breed that they could never study enough dogs to get meaningful results.
So in the new study, Evan MacLean, a comparative psychologist at the University of Arizona in Tucson, Noah Snyder-Mackler at the University of Washington in Seattle, and colleagues began by looking at behavioral data for about 14,000 dogs from 101 breeds. The analyses come from the Canine Behavioral Assessment & Research Questionnaire (C-BARQ), a sort of pet personality quiz developed by James Serpell, an ethologist at the University of Pennsylvania. C-BARQ asks questions like, "What does your dog do when a stranger comes to the door?" to allow owners to objectively characterize 14 aspects of their pet's personalities, including trainability, attachment, and aggression. Since the survey was developed in 2003, more than 50,000 owners have participated.
As research continues to uncover the links between genetics, environment, and human influence, one thing is clear: dog behavior is as complex and individualized as our own. Breed may offer clues, but it’s the relationship between people and their pets, the shared experiences, energy, and affection, that truly shapes who our dogs become.
