Countless times throughout my four decades as a veterinarian, people have repeatedly expressed their fervent belief that how a dog behaves is the result of how that dog is raised. People have convinced themselves that if a dog ever tries to bite, it’s because the dog was mistreated or maybe someone was doing something to antagonize the dog or possibly the dog’s owner wasn’t raising the dog properly (similar to when a child misbehaves and people conclude that it’s the child’s parents who are at fault.)
There’s no question that behavior (both dog and human) is impacted by the way an individual is treated, especially if there’s any kind of mistreatment or abuse. I don’t believe, though, that environmental factors are the greatest determiner of an individual’s personality and behavior. That honor, in my humble opinion, belongs to DNA. The impact of genetics on personality and behavior has been severely downplayed in the past and this book is an attempt at refuting that misconception.
The difficulty with DNA is that it’s essentially invisible and, as such, it isn’t something that we think of very often. The truth is no matter how much one examines the exterior of something, it’s not possible to comprehend what’s going on underneath that exterior. This is definitely the case when it comes to human beings. There’s so much more to a human being than skin, hair, eyes, nose, mouth, and the rest of our external features. Yet, those external features are what we focus on whenever we’re interacting with one another since those are the things that we can see. What we can’t see and what rarely comes to mind are the millions of individual cells inside our bodies, the miles of blood vessels and nerves, the heart that steadily pumps, the brain that continually coordinates our thoughts along with all the other organ systems that perform their duties inside our bodies completely hidden from sight. The internal components of our bodies may be hidden from view but they’re vitally important and we need to take them into consideration if we ever hope to fully understand who we are as a living being. Regrettably, except for the times when one of those internal systems fails or causes us problems, they’re mostly out of sight and out of mind.
On the other hand, it’s quite easy and natural for us humans to focus and even obsess on the exterior aspects of our bodies. We’re also quite focused on the environmental events and circumstances that impact our lives. The environmental facets of our lives (our families, socio-economic status, education, social interactions, etc.) are always the first place we look when we’re contemplating what’s influencing our personality and behavior. Personal experiences and circumstances are always going to be foremost in our thoughts as that’s what we’ve experienced, what we’ve seen, heard, tasted, smelled and felt. Rarely does it cross our minds that something that we can’t see is actually the primary determiner of our personality and behavior: DNA.
DNA is even more inaccessible than our internal biology which can at least be accessed through various types of blood tests, imaging (such as x-rays and MRIs) and surgical procedures. Though DNA is something that we rarely think about, that doesn’t alter the fact that our DNA defines us just as intimately as water defines the ocean.
It might help us in our efforts to understand how important DNA is as concerns our personality and behavior if we first look at the way in which DNA impacts the reasons dogs bite. Before I begin that discussion, though, I’d like to quickly clarify two important points.
First off, throughout this book, I’ll be discussing the traits and characteristics of different breeds of dogs and I have no doubt that I’ll unavoidably make some comments or generalizations about a certain breed of dog that will end up offending someone who has a fondness or devotion to that particular breed. Some of my comments will not be complimentary and may, as a result, feel unfair or unduly critical. I am quite aware that any generalization I make about a particular breed of dog will NOT hold true for every single dog in that breed as there are always exceptions to any generalization. Most importantly, I want to emphasize that it’s definitely not my intention to malign any breed of dog simply for the sake of being spiteful. I’m hoping that the reader will take these generalizations in the same light they might if I were discussing the characteristics of certain cars. In a discussion of cars, I might easily make a generalization as to how certain models of cars (i.e.- sport cars or race cars) are more dangerous than others. Making a generalization such as that wouldn’t be an intentional dig against Porsches, Corvettes and Ferraris. The fact that these cars have extraordinary speed and power is a simply statement of fact without any judgement or condemnation. Similarly, the generalizations I’ll be making about certain breeds of dogs are solely based on my experiences during my forty years as a veterinarian. I’m merely describing what I’ve observed and experienced as a veterinarian and, as is true of certain models of cars, certain breeds of dog are more dangerous than others in my experience.
Secondly, though it’s the contention of this book that DNA exerts the greatest impact on our personality and behavior, I’m not discounting that environmental circumstances have a very important influence on our personality and behavior. Both genetics and environment contribute to the makeup of an individual. As to the percentages that genetics and environment impact personality and behavior, those have yet to be determined. This book asserts that DNA is the master builder for personality, temperament and behavior, that it’s our DNA that actually dictates how we respond to our environment.
Clarifying these two points will hopefully set the tone for the rest of the book and help the reader understand that my comments and generalizations are based on my forty years of experience as a veterinarian and that I am not minimizing the importance of environment in the formation of personality and behavior. With that behind us, let’s take a look at the genetic reasons as to why a dog might bite.
To get us started, I’d like to share a story about a dog that came into my veterinary clinic one day in Camarillo, California. Busy as usual on this particular day, my staff and I were startled when two police officers charged through the front door of the clinic carrying a severely injured Labrador Retriever. The officers explained that the dog’s owner had gone berserk for some reason and had beaten the dog with a baseball bat.The poor dog had survived but he’d sustained a nasty broken leg along with many other blunt force injuries. As a result of those injuries, the dog ended up staying at the clinic for several days. During that time, it was heartbreaking for me and my staff to watch the dog’s terrified response to being close to people as a result of his horrible ordeal. Each time any of us went near the dog, he’d curl up into a ball as best he could, cowering and trembling uncontrollably. He’d even urinate on himself if he got too scared.Yet, in spite of the beating he’d received at the hands of his owner along with the various medical procedures we were forced to put him through as part of his recovery, the Lab never tried to bite. In fact, he never even growled. What was astonishing was the fact that, even though he was clearly terrified of people, he actually seemed to love being petted! After he got past his initial reaction of cowering and trembling, some other aspect of his temperament took over and we could see him start to relax, his body gradually melting in response to our touch. Next, his eyes would soften and turn all doe-eyed and, before long, we would hear the thump, thump, thump of his tail hitting the bottom of the cage. He was terrified but his underlying personality and temperament were that of a love bucket! The dog obviously didn’t have it in him to even try to bite as biting was simply not a part of his character. And, the sole reason he was such a sweet dog despite being terrified had to do with the fact that he had the genetics of a Labrador. Genetically, Labradors are extremely friendly dogs that rarely (if ever) bite out of fear or aggression. On the other hand, if that Lab had been a different breed of dog, a breed that was more defensive, fearful or aggressive, there’s no doubt in my mind that we’d have seen a lot of growling and snapping.
Dogs bite for a variety of genetic reasons and most of those reasons originate with the dog’s breed. Dogs have been bred for very specific purposes over the centuries and that’s how all the different breeds of dogs came about. Each breed of dog has its own traits and characteristics that are typical for that breed. Depending on the genetics of an particular breed of dog, some dogs will be much more protective and aggressive than other breeds just as certain breeds of dogs will be more standoffish and fearful. The breeds of dogs that are fearful and standoffish will typically use biting as a way to protect themselves and to get people or other dogs to leave them alone. Fear-biters are dogs that anticipate the worst possible case scenario and instinctively they adhere to the Vince Lombardi adage that the best defense is a good offense. Dogs that are fearful are convinced that they had better get you before you get them! Thankfully, most fear-biting dogs only bite when someone is messing with them when they don’t want to be messed with. Fear-biters will snap and bite primarily as a warning and then they’ll quickly back away as they don’t want anything more than to be left alone. Fear-biters are typically a one bite dog as opposed to aggressive dogs that will attack and continue to attack to the point it’s nearly impossible to get them to stop.
Protective and aggressive breeds of dogs have a completely different outlook from that of the fear-biters. Biting for protective and aggressive dogs is simply a part of their job as it’s what they’ve been bred to do. A protective or aggressive dog’s motto is to bite first and ask questions later! Rottweilers, Mastiffs, Pit Bulls and German Shepherds are examples of dogs that have been bred specifically to guard and attack, even to the point of accompanying soldiers into war. Protective and aggressive dogs are not fearful but they’re not especially friendly either. These dogs have been bred to be leery and suspicious of strangers and, consequently, they can be very quick to bite in any situation that the dog finds is stressful or unfamiliar.
Herding dogs, such as Australian Shepherds, are dogs that have been bred to bite and nip as a means to defend and protect the animals (sheep, goats and cattle) in their charge as well as to get those sheep, goats and cattle to do what the herding dog needs them to do. Biting is not only a tool to protect the herd under their control but it’s the ultimate in tough love as these herding dogs must be able to control and manipulate the herd.
Terriers are a class of dog that were bred specifically to hunt and kill rabbits, rats, foxes or any other animals that were deemed problematic to humans. As a result, terriers have an extremely sensitive “attack” instinct that’s easily triggered whenever they’re challenged, stressed or stimulated by what appears to be a prey running away. Until it was made illegal, Pit Bull terriers were bred in England to attack huge animals, such as bulls, bears and boars, in a bloody sport called “baiting.” Pit Bulls were specifically bred to have sufficient stamina and strength so that they could latch onto an animal and not let go until that animal was defeated or dead. That’s exactly the reason Pit Bulls can be so dangerous because, if they decide to bite, their breeding compels them to latch on and never let go. Unfortunately, there are certain unscrupulous people who breed these aggressive dogs so they can participate in illegal “to the death” dog fights.
There are other genetic reasons as to why dogs bite. Biting is actually a very normal part of the pack dynamic in which a group of dogs continually work out the pack’s pecking order. Dogs naturally bite when they are playing with one another and when they join together to take down a prey. Biting is a normal and expected part of being a dog and pet owners need to understand that many dogs are going to bite someone at some point even if they are a nice and friendly dog most of the time.
Now that we’ve examined how DNA is behind the various reasons that dogs choose to bite, I want to share a fascinating genetic study that explored how DNA impacted the tameness and domestication of animals. In the March 2011 edition of National Geographic there was an incredible article titled “Designing the Perfect Pet.” The article described in detail a half-century research project that was conducted in southern Siberia by a biologist by the name of Dimitry Belyaev.
Belyaev initiated his experiment using one hundred and thirty wild foxes that he’d purchased from various fox farms in Siberia. The objective of his experiment was to determine how long it would take to strategically breed wild foxes to the point that they became tame and domesticated. With each successive litter, Belyaev would carefully select those pups that were the least fearful of humans and he’d then breed those foxes to one another. After only nine generations, Belyaev had managed to produce a group of foxes that were so thrilled in the presence of humans that they whimpered, whined and wildly wiggled their bodies and wagged their tails in ecstatic anticipation of being petted by a human.
Belyaev also performed experiments to determine what impact a foxes’ environment would have on their tameness and domestication. To that end, he selectively bred a line of human-aggressive foxes that were so agitated by humans that they’d either recoil in fear at the back of their cages or they’d viciously attack the cage, gnawing at the wire mesh until their gums bled in the efforts to break out of their cage and attack the person standing there.
Belyaev’s experiment investigated the question as to whether puppies born to human-aggressive mother foxes could become tame if they were raised by a human-friendly mother fox. In trial after trial, Belyaev found that the fearful and combative traits that had been bred into the human-aggressive pups were not in the least diminished by being raised by human-friendly mother foxes. Belyaev and his colleagues were forced to conclude that tameness was a genetic issue and not an environmental one. Belyaev and his research team were eventually able to distinguish the DNA of the tame foxes from that of the human-aggressive foxes.
Since DNA isn’t easily visualized or quantified in our every day lives, it’s always going to be difficult for us to appreciate just how much it actually dictates our personality and behavior. DNA is like the wizard hiding behind the curtain in Oz: unseen but clearly the master puppeteer who’s pulling the strings on our personality and behavior.
The impact that DNA had on human behavior was dramatically exposed in a revolutionary study that was performed on identical twins who separated at birth. As identical twins originate from the exact same egg and sperm and contain the exact same genetic material, studying identical twins who were separated at birth gave the researchers the perfect opportunity to differentiate traits and characteristic that were genetic (nature) from those that were environmental (nurture.) Ordinary siblings and fraternal twins couldn’t have been used for this kind of study since siblings and fraternal twins only share fifty percent of their genetic material due to the fact that they’re conceived from different eggs and sperm.
The insights discovered from this study, called the Minnesota Twin Family Study, were groundbreaking, Starting in 1979, Thomas Bouchard and a team of psychologists spent twenty years studying one hundred thirty-seven sets of identical twins who had been raised apart from birth.
The most important revelation uncovered by the Minnesota Twin Family Study concerned the discovery that the temperament, attitude and the interests of identical twins raised apart were no different from the temperament, attitude and interests of identical twins raised together. What this means is that the traits that persevered in the twins, whether they were raised apart or together, were the result of their shared genetic material.
Before this study, the general consensus of the psychological community was that temperament and behavior arose from environmental influences. The Minnesota Twin Family Study kick-started a revolutionary new awareness that DNA apparently had a much greater impact on temperament and behavior than had ever been previously believed.
One incredible example from the Minnesota Twin Study is so surreal and unbelievable that it deserves mention. It involved a set of twins who were separated at four weeks of age and who weren’t re-united until they were thirty-nine years old. Incredibly, both boys were named James by their adoptive parents (as if there was something intrinsically compelling about their countenance that inspired that particular name.) As children, both boys had dogs that they’d named “Toy.” As adults, both men were currently married to women named Betty and both had been divorced from women named Linda. Each man had christened his first-born son James and both had given their son the middle name of Alan (though one had spelled it “Allan”). Each man had previously worked as a sheriff and both men were currently employed as firemen. They both enjoyed woodworking as a hobby and they each drove light blue Chevrolets and the both vacationed each year at Pas Grille beach in Florida. They both smoked Salem cigarettes and drank Miller Lite beer, both holding the beer cans by the bottom using their pinky finger. They both compulsively bit their fingernails and suffered from migraine headaches. Both men had the habit of leaving love notes for their wives in various places around the house and both men gained ten pounds at the same time for no apparent reason.
The Minnesota Twin Family Study gave the world its first powerful glimpse into the amazing world of genetics. The full extent as to which DNA impacts personality and behavior won’t be known for many, many years since the study of genetics is in its infancy. Though we’ve clearly come a long way in our understanding of DNA, if all there is to know about genetics is Mount Everest, we’ve only reached the first base camp. The fact is that there’s an entire mountain’s worth of knowledge for us yet to explore!
This book is devoted to the importance of genetics, especially as regards temperament. Once we’re able to accept just how much DNA dictates our lives, it should be much easier for us to accept our own (and other people’s) temperament and behavior in the same way that we accept that the behavior of our dogs is dictated by their breeding (DNA).
In the next chapter, we’ll explore in detail the fascinating topic of temperament. We’re going to discover that DNA dictates our temperament and behavior just as much as it dictates the color of our eyes and hair. Woof!