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 since it’s microscopic and, as such, it’s not something we tend to think about very often if at all. Yet, the truth is that no matter how much one examines the exterior of something, it’s not always possible to understand what’s going on inside that exterior. This is definitely the case when it comes to us human beings. There’s so much more to a human being than simply skin, hair, eyes, nose, mouth, and the rest of our external features. Yet, those external features are invariably 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 continuously coordinates our thoughts and feelings while all our other organs perform their duties unseen inside our bodies. The internal components of our bodies may be hidden from view but they’re vital and it’s critical that we think about them and take them into consideration if we’re ever to fully understand who we are as a living being. Regrettably, though, except for the times when one of our internal organs fails or causes us problems, they are mostly out of sight and out of mind.
On the other hand, it’s quite easy and natural for us humans to focus on and even obsess about the exterior aspects of our bodies. We’re also invariably 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 forever foremost in our thoughts because they’re what we’ve experienced, what we’ve seen, heard, tasted, smelled and felt. Rarely does it ever cross our minds that something that we can’t see might actually be the primary determiner of our personality and behavior: that’s right, our 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, not thinking about it doesn’t alter the fact that DNA defines us just as intimately as water defines the ocean.
It might help us in our efforts to understand how important DNA is with respect to our personality and behavior if we first look at the way in which DNA impacts the reasons that 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 be making some comments or generalizations about certain breeds of dog that will end up offending people who have a fondness for those particular breeds. Some of my comments will NOT be complimentary with respect to certain breeds and, consequently, may feel unfair or unjustified. I’m quite aware that any kind of generalization that I make about a particular breed of dog will NEVER hold true for every single dog in that particular breed as there are always going to be exceptions to any generalization.
Most importantly, I want to emphasize that it’s not my intention to malign any breed of dog simply out of spite. I’m hoping that the reader can take these generalizations in the same light as 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 a race car being potentially more dangerous than some other type of car would never be construed as some spiteful, irrational dig against Porsches, Corvettes and Ferraris. The fact that these cars have extraordinary speed and power is a simply statement of fact devoid of unfair or unjustified judgement or condemnation. Similarly, the generalizations I’ll be making about certain breeds of dogs are based on my experiences during my forty years as a veterinarian and on facts and statistics. It’s my duty as a professional to try to protect people (especially children) with information concerning certain breeds dogs that the facts and my experience as a decades long veterinarian indicate are more dangerous than other breeds of dogs. There is no way that this isn’t going to upset some people but it is my sworn duty as a professional and I do it with no pleasure. I don’t like denigrating any breed but I must tell the truth not only as I know it but as the facts dictate.
Secondly, though I contend in this book that DNA exerts the greatest impact upon our personality and behavior (as I also contend it does with dogs), I’m not in any way discounting that environmental circumstances have an extremely important influence on personality and behavior. Both genetics and environment contribute to the makeup of any individual. As to the relative percentages that genetics and environment contribute to personality and behavior, those percentages are yet to be determined. This book simply contends that DNA is the master builder for our personality, temperament and behavior, that DNA dictates how we each respond to our environment.
I hope that clarifying these two points will make it clear to the reader that I am not minimizing the importance of environment in the formation of personality and behavior and that any unappreciated comments made by me about a particular breed are made solely with the safety of the public in mind. With that behind us, let’s take a look at the genetic reasons why a dog might bite.
To get 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 and had beaten the dog repeatedly with a baseball bat.The poor dog had survived the assault but he’d sustained a nasty broken leg along with many other blunt force injuries. Due to the severity of his injuries, the dog stayed at the clinic for several days. During that time, it was heartbreaking for my staff and I to watch the dog’s terrified response at being approached by any of us. This poor creature was clearly emotionally traumatized from the horrible treatment he’d received at the hands of his owner. Each time any of us went near him, he’d curl into a ball and retreat to the back of the cage, cowering and trembling uncontrollably. He’d actually urinate on himself if he got too scared.Yet, despite the beating he’d received at the hands of his owner in additiont to all the various medical procedures we had to put him through as part of his recovery, this abused and mistreated Labrador never once growled or tried to bite. What was astonishing was that, even though he was clearly terrified of people, there was some part of him that desperately wanted to be petted. After he’d get past the initial terror of being touched, some repressed but innate part of his Labrador temperament would begin to assert itself and he’d ever so gradually start to relax. We could feel his body slowly melt in response to our touch and, before long, his trembling would stop. He’d start making furtive glances in our direction instead of hiding his head in the corner of the cage. After a little longer, he’d look at us more directly and we could actually see his eyes soften, becoming doe-eyed. Then, we’d hear the greatest sound in the world: the barely audible thump, thump, thump of his tail hitting the bottom of the cage. Despite his terror, he had the underlying personality and temperament of a love bucket! Though he’d been abused about as badly as any dog could be abused, this dog genetically didn’t have it in him to growl or bite because doing that simply wasn’t a part of his innate temperament or character. He was a sweet dog at heart despite being abused because he possessed the DNA of a Labrador.This is NOT to say that there aren’t some Labradors out in the world that bite. But, generally, Labradors are genetically friendly dogs that rarely (if ever) bite out of fear or aggression. On the other hand, if that Labrador had been a different breed of dog (such as a Chihuahua, a Manchester Terrier or a Chow) which is more genetically prone to being defensive, fearful or aggressive, there’s not any doubt in my mind that my staff and I would have seen a lot of growling and snapping.
Dogs bite genetically for a variety of 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 various types of 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 a particular breed of dog, some dogs will be much more protective and aggressive than other breeds of dogs just as certain breeds of dogs might be genetically 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 they instinctively adhere to the Vince Lombardi adage that the best defense is a good offense. Dogs that are fearful go on the offense because they are convinced that if they don’t growl or snap first, something terrible is going to happen to them! Fear-biters snap and bite primarily to protect themselves which is why they tend to only snap or bite once as a warning. Fear-biters loathe the thought of actually getting into a fight. All they want is to be left alone.
Protective and aggressive breeds of dogs have a completely different outlook on biting from that of the fear-biters. Biting for protective and aggressive dogs is simply a part of their job and it’s typically a part of the purpose for which they were bred. A protective or aggressive dog’s motto is to bite first and ask questions later! Rottweilers, Mastiffs, Pit Bulls, Malinois, and German Shepherds are examples of dogs that have been bred specifically to guard and attack. Some of these breeds actually accompanyied 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 in which the dog finds itself that 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 against predators but biting at the heels of the herd is the ultimate in tough love as this is how these herding dogs 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 is easily triggered whenever these dogs are challenged, stressed or stimulated by what appears to be a prey running away from them. 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 such that they were able to latch onto an animal’s throat and not let go until that animal was fatigued, bled out or dead. That’s the reason Pit Bulls can be so incredibly dangerous because, if something triggers them to bite, their breeding compels them to latch on and to never let go. Horrifically, there are unscrupulous individuals in the world who specifically breed these dogs to be as powerful and aggressive as is possible so they can participate in illegal “to the death” dog fights.
There are countless genetic reasons why dogs bite. That’s why it needs to be understood that biting is a very normal and instinctive part of being a dog. Biting is intrinsic to the dynamics of the pack in which a group of dogs must continually work out a pack’s ever changing pecking order. Dogs bite to establish to who’s top dog. Dog’s bite to establish who’s going to eat first, who’s going to breed first, along with countless other issues involving the rank in the pack’s pecking order. Dogs also bite when they’re playing. Dogs bite when they take down prey. The reality is that biting is a perfectly normal and expected part of a dog’s existence and pet owners must understand this and be prepared for the fact that most dogs are going to bite at some point in their lives even if they’re normally a nice and friendly dog the majority of the time. Biting is simply what dogs do because that’s how they communicate their wants, needs and fears.
Now that we’ve examined some of the reasons why dogs instinctively bite, I’d like to share a facinating study that will demonstrate how DNA intimately impacts the tameness and domestication of animals. In the March 2011 edition of National Geographic, there was an article titled “Designing the Perfect Pet.” The article described in amazing detail a half-century research project conducted in southern Siberia by a biologist by the name of Dimitry Belyaev.
Belyaev initiated his experiment using one hundred and thirty wild foxes he’d purchased from various fox farms in Siberia. The objective of his experiment was to determine how long it’d take to strategically breed wild foxes such that they’d finally become tame and domesticated. With each successive litter, Belyaev carefully selected those pups that were the least fearful of humans and he’d then breed those foxes to each other. After only nine generations, Belyaev had managed to produce a group of foxes that were so thrilled in the presence of human beings that they’d whimper, whine and wildly wiggle their bodies and wag their tails in anticipation of interacting with a human.
Belyaev also performed experiments to determine what impact environment (or nurture) might have on the foxes’ tameness and domestication. To that end, he selectively bred a line of human-aggressive foxes that would become so agitated by the presence of human being 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 an effort to break out of their cage so as to attack the human being that was present.
Belyaev’s experiment investigated the question whether a puppy that was born to human-aggressive mother fox could end up being tame if it was raised by a human-friendly mother fox. In trial after trial, Belyaev found that the fearful and combative traits that had been bred into a human-aggressive pup were NOT in the least bit diminished by that pup being raised by human-friendly mother fox. Belyaev and his colleagues had no choice but to conclude that tameness was a genetic issue and not an environmental one. Belyaev and his research team were actually able to finally discover and distinguish which individual genes were different in the human-friendly foxes as compared to the genes of the human-aggressive foxes.
Since DNA isn’t easily visualized or quantified in our every day lives, it’s naturally going to be hard for us to appreciate just how much it dictates our personality and behavior. DNA is like the wizard behind the curtain in Oz: unseen yet the undeniable master puppeteer that’s pulling and manipulating the strings which control our personality and behavior.
The impact that DNA has on human behavior was exposed in a revolutionary study which concerned identical twins that had been separated at birth. Since identical twins originate from the exact same egg and sperm and contain the exact same genetic material, studying identical twins that were separated at birth gave researchers the perfect opportunity to differentiate traits and characteristic that were genetic (nature) from those that were environmental (nurture.) Ordinary siblings and fraternal twins could not have been used for this kind of study due to the fact that siblings and fraternal twins only share fifty percent of their genetic material since 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. The study concluded that the traits that were persevered in the twins (whether they were raised apart or together) were the consequence 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 exerted 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 they both men vacationed every year at Pas Grille beach in Florida. Both men smoked Salem cigarettes and drank Miller Lite beer, each of them holding the beer can by the bottom using their pinky finger. Both men compulsively bit their fingernails and suffered from migraine headaches. Both men were in 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 to which DNA impacts personality and behavior won’t be truly realized for years and years due to the fact that the study of genetics is in its infancy. Though we’ve come a long way in our understanding of DNA, if all there is to know about genetics is Mount Everest, we’re only at the first base camp. The truth is that there’s an entire mountain’s worth of knowledge for us yet to explore and discover!
This book is devoted to the importance of genetics, especially as regards temperament. Once we finally accept how much DNA dictates our lives, it should become easier and easier for us to accept our own (and other people’s) DNA as being the determiner of our individual temperament and behavior in the exact same way that the behavior of our dogs is dictated by their 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 it dictates the color of our eyes and hair. Woof!