Dogs are like snowflakes—they're magical alone, even better in groups, and no matter how many similarities they might have, no two are exactly alike. Every dog has a unique personality, that's a given. But what shapes those unique pupper personalities? What sets the course of what kind of dog a puppy will grow up to be: his genetics or his life story? In other worse, are dog personalities shaped more by nurture or nature? Here's everything you need to know about where dogs fall in this long-standing scientific debate.
The nature vs. nurture debate:
Before you can understand how nature and nurture play into forming your dog's personality, you need to know the basics of the nature vs. nurture debate.
The nature vs. nurture debate is a mainstay of modern psychology that deals with how different behaviors and personality traits are explained. There are two sides of the debate, the "nature: side, which argues for inherited and genetic origins of traits, and "nurture," which suggests that our behaviors and personalities are influenced more by our environments and experiences.
In other words, are our personalities set in stone at the DNA level from the moment we're born or are they shaped by the way we're raised and the experiences we have? Would you be—at your core—the person you are today if you'd been raised by different parents in a different place? Don't feel bad if you don't have an answer—science doesn't either. Not definitively, anyway.
In humans, the nature vs. nurture debate acts like a sort of continuum, with some experts falling on the extreme nature side, others on the extreme nurture side, and most somewhere in the middle:
So, how does all of this relate to dogs? Let's break down the evidence.
How does nature shape dogs' personalities?
Most experts agree that, when it comes to dogs at least, nature does play a significant role in determining personality. In 2008, researchers pointed out that many behaviors, like herding, pointing, tracking, and hunting, which are passed down through breeds of dogs and become instinctual, even without training, "are likely to be controlled, at least in part, at the genetic level." In their review, the researchers explained, "Recent studies in canine genetics suggest that small numbers of genes control major morphologic phenotypes. By extension, we hypothesize that at least some canine behaviors will also be controlled by small numbers of genes that can be readily mapped."
As researchers noted in a 2017 investigation of genetics and dog personality traits, "The genetic component of dog behavior is supported by between-breed differences and some evidence of within-breed variation."
Translation: We know that genetics plays a role in dog behavior because different breeds of dogs have different, distinct shared personality traits, and because we can predict a puppy's behavior, to a degree at least, based on the personalities and temperaments of its parents. Combined, those two facts are compelling evidence for nature's role in shaping the dog your puppy grows up to be.
That being said, the researchers mentioned above? They found, "significant genetic variation for most of the behavioral traits studied in a population of Labrador Retrievers" they studied and concluded that while, "chromosomal regions associated with some traits were suggested by genomic analyses...additional data will be required to fully capture the genomic variance and to confirm and resolve the genomic associations."
Translation: Yeah, we know that Labs, for example, tend to share a set of common traits. And yeah, we know that if you breed two really mellow, friendly Labs, the likelihood that their puppies will be mellow and friendly is pretty high. But, when you look at the actual genes and chromosomes of these mellow, friendly Labs, there are enough differences that scientists aren't yet able to say, "THAT is the mellow gene and THAT is the friendly gene. We cracked it."
How does nurture shape dogs' personalities?
There's also evidence that nurture, or the way we raise our dogs, plays a significant role in shaping their personalities. In a study by Enikö Kubinyi, Borbála Turcsán and Ádám Miklósi of Eötvös University in Budapest, Hungary that was published in the journal Behavioural Processes, researchers found clear links between certain life experiences and personality traits for dogs.
The study, which included 14,004 dogs from 267 breeds (and 3920 mixed breed animals), focused on four personality traits in particular: calmness, trainability, sociability, and boldness.
The study found correlations in dogs' experiences and upbringings and their personalities. For example, dogs were more likely to be calm if they were owned by men, lived in a home with several other dogs, and had lived in the same home since they were 12 weeks old or younger. The researchers shared other trends in correlations between experience and personality in their findings.
Experts stress that dog personalities are determined by a combination of nature and nurture.
"Thinking that genetics are destiny — that if a problem is 'genetic,' it can't be changed," dog genomics expert Jessica Perry Hekman told _Scientific American _when asked about the biggest thing dog-lovers get wrong about dog genetics. "Sometimes that's true, but very rarely in the case of behavior problems. A dog's personality is inextricably made up both of genetics and experience, and if you're seeing problem behaviors, it's always worth exploring what it might take to fix them. (On the other hand, if you're trying to get your retriever to be less interested in balls, this is likely to be an uphill battle.)"
Is dog aggression caused by nature or nurture?
One of the traits that scientists and dog lovers in general are most interested in getting to the root of is aggression. It makes sense that this topic generates so much interest—eliminating the aggression gene or pinpointing the experience that leads to aggressive behavior could help prevent dog bites and the need to put down dogs who struggle with aggression.
In a study published in Frontiers in Psychology, researchers from the University of Arizona showed a link between two different hormones—oxytocin and vasopressin—and aggression in dogs. According to National Geographic's coverage of the study, service dogs, which are bred to have a "placid temperament," have much higher levels of oxytocin in their blood than most dogs and aggressive dogs' blood has higher levels of vasopressin.
That's not to say that aggression is totally genetic—nurture definitely plays a role in triggering the behavior. But, this research suggests, some dogs are more naturally inclined to react aggressively and might become aggressive more easily than other dogs, based on their hormone levels.
"Before we can work to alter aggression, we need to understand its basic biology. No one had even looked at these other hormones before," Evan MacLean, a psychologist and anthropologist who worked on the research, explained.