Imagine this: a purse falls off a chair in the vicinity of two seven-month-old puppies. Terrified, one of the puppies refuses to go anywhere near it. Her sister takes a look, gives it a quick sniff and then leaps over it and goes on her merry way. Scenarios like this happen every day to Holly and Kit, the Border Collie/Beagle mixed-breed pups adopted by the editor of The Bark a few months ago.

Rescued from a shelter in Kentucky early this year, littermates Holly and Kit have been in their new home in northern California for several months now. As far as is known, the pups’ first five months of life were less than ideal; they seem to have lived outside on their own and had little contact with people. Not surprisingly, they arrived at their new home timid and shy. Since then, Kit has come out of her shell, romping happily around local off-leash parks with her “big sister,” Lola. Holly is a different story; she is sweet and loving at home, but extremely skittish in other contexts. But even at home, small changes in the environment—like a purse falling from a chair—overwhelm her.

That sisters would behave differently isn’t shocking to any of us with siblings or children, or anyone who has watched one puppy battle through life while a littermate calmly accepts whatever comes her way. We all know that sisters and brothers, whether human or canine, are not clones. No matter how similar the upbringing, minor differences in siblings’ genetic make-up account for major differences in behavior. But beyond that, what do we know about what influences a dog’s approach to life? What’s new in our understanding of the ontogeny of fear? In particular, what can make a fearful dog like Holly so different from her more outgoing sister?

Genetic Blueprints. The answer begins, of course, in the genetic make-up of each dog, which is unique to that individual. After all, the point of sexual reproduction—an inefficient and messy process (genetically speaking)—is variation. Each parent contributes one strand of DNA to the double helix that makes up each chromosome, and the strands link up in unique ways each time a new life is created. Thus, every individual is the result of a unique combination of genes. In an environment with a range of conditions—perhaps a drought one year and floods the next—genetic variation ups the odds that some individuals will survive even if others perish, thus ensuring continuation of at least some individuals of their particular species.

This variation isn’t news to dog lovers—we are all well acquainted with canine physical variation, from flat-nosed Pugs to skinny-muzzled Salukis. This genetically mediated variation is equally true of behavioral predispositions. According to research done over the last 30 years on personality, one of the most heritable behavioral characteristics relates to the behavior of Holly and Kit. What is now called the “shy-bold continuum” has been found to be a relatively stable aspect of personality in rhesus macaques, cattle, people and dogs (to name a few). It appears as though different points on the “shy-bold” spectrum are advantageous at different times. For example, primatologist Steve Suomi has found that in some conditions, shy male rhesus macaques have higher reproductive success than bold ones. The shy males wait longer to leave their natal troops, and thus arrive at a new troop larger and better able to hold their own when challenged by established males. (But sometimes it helps to be brave and bold; what if there are only a few troops in the area and the bold monkeys become established in them before the shy ones venture forth?)

One can easily imagine how, in some contexts, the progenitors of domestic dogs were best served by boldness (being the first to venture near a human settlement) or by caution and timidity (letting a littermate be the one to go play with that big, fuzzy animal that humans call lions). What is not clear yet is how much of a dog’s physical appearance is linked to behavioral tendencies. Holly looks more like a Border Collie than does her sister Kit and, in general, we know that shyness is relatively common in many of the herding breeds. Could there be a link between looks and personality?
There has been shockingly little research on the links between physical appearance and behavioral tendencies, but Swedish ethologist Kenth Svartberg did some interesting work on personality in dogs while at Stockholm University. One of his studies found “large behavioral differences between breeds in the traits [of] playfulness, curiosity/fearlessness [similar to the “shy/bold” continuum mentioned earlier], sociability and aggressiveness.” Clearly, there appear to be strong genetic links between looks and behavior. Does that mean that more of Holly’s genes relate to the Border Collie in her? Could be. Of course, we’ll never know, but it is certainly possible and biologically logical to predict links between a dog’s appearance and her personality, even within a litter.

Starter Houses. Beyond an understanding of the role of genetics, research is increasingly focused on the effect of in-utero experiences on the development and, ultimately, the health and behavior of an individual. Until recently, our developmental considerations have focused on the influence of genetics and the environment during “early development”—the old nature/nurture argument, as it were. The period we defined as “early development” began at birth and followed an animal through infancy, childhood, adolescence and adulthood. However, new information has alerted us to the important influence of in-utero experiences, an environment we’ve never before considered as having an affect on an adult animal. Much of the research I’ll mention here was done on humans, but there is no biological reason to not generalize it to canids.

In general, the influence of a mother’s experience on her fetus is profound: her sleep pattern teaches the developing child about the cycle of day and night. Her food preferences influence her baby’s after birth. If the mother is seriously deprived of food, her infant will be predisposed to diabetes and high cholesterol as an adult. Most relevant to a fearful puppy, a mother suffering from extreme anxiety puts her offspring at high risk of being anxious and fearful, even as an adult. Apparently, high levels of the stress hormone cortisol produced by the mother result in fewer cortisol receptor cells in the pup (or child or monkey, etc.). This low number of receptor cells means that the pup’s brain is unable to perceive and respond to high levels of cortisol in his own body until the system is overloaded with it. Then the brain goes on red alert, sending the emotions into full panic mode, even in situations that would be only mildly stressful for an average individual.

In addition to the significant influence of a mother’s influence on her young, we also know now that the experience of each individual within the uterus is different. Minor differences in nutrients, for example, have long been known to be a factor in major differences in the size and health of animals within a litter. Even genetic clones—identical twins for example—aren’t behaviorally identical. Though they may look alike, they usually have remarkably different personalities. Since they developed with the same set of genes, only in-utero experiences can account for their behavioral differences. Developmental psychologists are learning that for twins, development in the womb is a kind of dance between the two that, by the time they are born, has shaped their personalities.

Another example of the influence of in-utero development is what’s called “androgenization.” In this phenomenon, females in a litter are permanently affected by the androgen produced by male puppies surrounding them within the uterine horns. Androgen is the precursor to testosterone, and females who are “bathed” in it, perhaps because of their placement between a large number of males, tend to behave differently than other females once they develop into adults. Androgenized females behave more like males, sometimes have enlarged gentalia and are often more aggressive to same-sex individuals.

And so, even prior to birth, profoundly different experiences could have shaped Holly and Kit. The combination of different genetic blueprints and different experiences inside the womb resulted in two dogs with very different personalities and tolerances. Even though they have grown up together, those beginnings mean that a similar environment will affect them in different ways as they continue to develop. Holly will probably always be more cautious than Kit, because much of who she is was established before she was born. This is not to say that shy little Holly can’t become more comfortable at the dog park—or with runaway purses—but it does remind us how and why every dog is a unique creation and special in her own way. And special they are, every one of them.

Good luck, Holly … we’re rooting for you!

Maddie was a lovely little dog, with creamy white fur and an open, smiley face. She seemed willing and smart and ready to learn, but her guardian had brought her to me because the dog was driving her crazy. Every time the family asked Maddie to sit and stay, she jumped up and licked their faces. No matter what they did, they couldn’t seem to get her to stay still, even for an instant. Someone told them it was because she was trying to assert “dominance” over them. Someone else suggested she’d been abused. Maddie had nothing at all to say on the topic, but kept cheerfully bounding up like a jack-in-the-box every time she was asked to sit and stay.

The same week, I had another client whose treatment plan included teaching his dog Bruno a variety of tricks. The first trick had him stumped, because no matter how hard he tried, and how many tasty treats he used, he couldn’t get Bruno to roll over. He tried and tried, and finally came into the office convinced that his dog was deficient.

Getting to the Heart of the Matter
Neither of these explanations had anything to do with the issues at hand. Both dogs appeared to be normal and happy, capable of learning as much as anyone wanted to teach them, and their guardians were dog-loving, intelligent people. The problems, though superficially different, were based on the same important truth: Anything that we think of as a “behavior,” like rolling over or asking a dog to sit and stay, is actually a summation of a great many tiny movements. These incremental movements add up into what we call “rolling over” or “giving a sit signal,” each of which is the sum of many parts.

Understanding this—that all actions are actually made up of many smaller ones—can elevate you from a moderately good dog trainer to a great one. The seemingly dim dog Bruno ended up learning to roll over in one session because all I asked him to do initially was to lie down and turn his head toward his tail. Of course, I helped him at first by luring his nose in the right direction with a piece of food, but in no time at all, Bruno was happy to offer the behavior on his own. “Look at my tail for chicken? I can do that!” Bruno began throwing himself down on the ground and enthusiastically twisting his head toward his tail, tail thumping furiously. Next, I asked him to move his head a bit farther back, this time turning it toward his other side, enough that his top foreleg began to rise off the ground. Bingo! More chicken. Step three included luring his head around even farther, until his body followed and completed the roll over in one smooth motion. The humans clapped and cheered, Bruno wagged and grinned, and the pile of chicken pieces rapidly decreased.

Bruno’s guardian, a relative novice at dog training, had tried to teach Bruno to roll over by luring his head around with tasty snacks, but because he thought of “rolling over” as, well, rolling over, it didn’t occur to him to give Bruno the snack until the dog had executed the entire action from beginning to end. Dog trainers see this problem on a daily basis—people who try to teach a dog to sit up or roll over, and end up throwing in the towel because they can’t get the dog to do what they want. This is one of those times when it would help if people were more anthropomorphic (rather than less so as we’re often advised). We don’t wait to praise our children until they play Beethoven’s Fifth Symphony perfectly, do we? Yet, that’s common behavior with our dogs—we often expect them to do it right all the way through the first time. Anything less is categorized as a failure.

We’re even less likely to think of our own actions as the summation of many tiny behaviors. Take Maddie, the dog who wouldn’t sit and stay. In the office, I suggested the guardians give it a try so I could see what was going on. The mom of the family stood up, turned to face Maddie, and said “sit” and “stay.” As she said “stay,” she backed up about a half a step. In response, Maddie sat politely, but then leapt up as soon as she heard the stay signal. “See what I mean!” her guardian said, with no small amount of exasperation in her voice. Next, I asked her to call Maddie to come.

You guessed it. She turned to face her dog; said, “Maddie, come!”; and then backed up exactly as she had when she said “stay.” Maddie was paying attention to one small component of the “stay” signal—the backward movement, which she had learned meant “come”—and bless her heart, she kept giving it her best shot, in spite of the confusing response of her humans. It’s a miracle they don’t bite us more often, truly.

Nothing’s Simple
These stories illustrate two perspectives about behavior that can illuminate our understanding of it. One is that a “simple” behavior like asking your dog to sit usually consists of several different sounds and movements, any one of which could be relevant to your dog. We may think that saying “sit” is a singular event, but to an observant dog (and believe me, they’re all observant!), there’s a lot more going on. You may be concentrating on the word, but as you say it, your hands, head and body are all probably moving in consistent ways, although you’re probably not aware of it.

My favorite exercise at seminars is to have a trainer ask her dog to sit, and then ask the audience how many different movements made up that “simple” signal. Usually we come up with at least six or eight movements and one spoken word, any of which could act as the relevant cue to the dog. The last time I played that game, we observed that each time the trainer asked for a sit, she nodded her head ever so slightly. Until her dog saw her nod her head, he would not sit. Once she did, he’d sit instantly. The dog was focusing on the nod, and the human was focusing on the word she was saying. I would bet money if you could’ve asked the dog to describe the signal for “sit,” the dog would’ve said, “Why, the head nod, of course!”

Bruno, the dog who finally mastered the “roll over” command, reminds us that even one continuous motion—like rolling over—is also the sum of its parts. The general principle of dividing an action up into steps is old news for many trainers, but we can profit from revisiting its importance. Even those of us who are long familiar with what’s called “shaping,” or the process of reinforcing incremental improvements in behavior, can benefit by remembering that it relates to everything that we and our dogs do.

Understanding that any behavior can be divided up into smaller parts is the guiding principle taught to all students of animal behavior. It was the first thing that I learned from my ethology professors at the university, and it’s the first thing good, psychologically based behavior analysts learn. The fields of ethology and psychology may have very different perspectives, but they agree completely on the importance of understanding behavior as a series of incremental actions. Step-by-step, brick by brick, the foundation of any behavior is built upon little things that add up to bigger ones. The better you are at deconstructing it, the better a trainer you’ll be.

In 1992, I fell in love with a dog named Luke. I brought him home from a herding dog trial one chilly October evening, not sure whether I’d keep him, not sure I wanted another dog. A gangly adolescent, Luke had been a disappointment to his first owner, who reported that he wouldn’t come when called and had failed his first herding lessons. I’d had my eye on him ever since he was a pup, and had told the owner to let me know if she ever decided to sell him. When she did (I had more dogs than I needed, but every time I saw Luke something clicked inside, as if I’d finally found the combination to an old padlock I carried around, unopened), I took one last look at his bright, expectant face, wrote out a check, and drove him home through the red and orange hills of a Midwestern autumn.

By sundown of the next day, Luke and I had fallen in love. I don’t know any other way to
describe it. I say “fallen in love” with the knowledge that eyes will roll, lips will purse, and heads will shake. “That’s pathetic,” someone said to me once when I described my love for Luke. It seems that people either get it or not; like the yes-no simplicity of digital computers, the world sorts us into those people who’ve been deeply moved by an animal, and those who can take them or leave them. I learned to censor myself, to test the waters by volunteering some platitude like “Yep, he’s a great dog, Luke,” instead of a deeper, more complex attempt to express how much I loved him.

Although the love we have for our dogs is often trivialized, there’s nothing trivial about it. A few weeks after my father died, one of my mother’s dogs was killed by a car. A visitor had come to help sort out my father’s affairs, and unbeknownst to anyone, Jenny the exuberant Irish Setter had dashed out the door, running free and wild and no doubt, full of innocent and cheerful abandon. She was killed half a mile down the road, in front of the church where my father’s service was held. My mother, stalwart and noble after my father’s death, sobbed so hard and for so long about her dog’s death that it seemed as if her grief would physically rip her apart. I thought at the time, as did many, that Jenny’s death allowed my mom to truly grieve the death of her husband. I don’t think so now. My mother loved my father, but their relationship was burdened with disappointments and perceived betrayals. But Jenny? Jenny sparkled with nothing but joy and devotion. She asked for little and gave everything she had in return. These were no hard words late at night, no angry glances or saturated silences. No baggage. She loved Mom; Mom loved her: simple as that.

We’re not always comfortable with the depth of emotion we can have for our dogs, but profound love isn’t uncommon. I recently read an article about a teenager who risked his life to save his dog from a burning building. A tough-minded rancher once told me he’d rather die than abandon his cattle dog in a snowstorm. The evidence is overwhelming that during the days leading up to Hurricane Katrina, hundreds if not thousands of people chose to risk death rather than leave their animals behind. The state of Florida learned this lesson well during 1992’s Hurricane Andrew, when thousands of people refused to evacuate because the shelters wouldn’t take pets. These decisions compromised the safety of so many people that the state now provides shelters for pets as well as for people.

The lengths that normal people will go to in order to protect their dogs testifies to the love and devotion many of us have for them. I remember a Wisconsin woman who was interviewed after a tornado destroyed her home and all of her belongings. “We’re okay,” she kept saying, clutching her dog to her chest, “we’re okay, that’s what matters.” “We’re okay” meant her husband, her children, and her dog; she wasn’t sorting them out by species. After the tragedy of Katrina, I heard discussions all over the country about what each of us would do if we were told to evacuate without our pets. What would you do if you had to choose between the safety of evacuation and risking your life to stay with your dog? Everyone at my office said we couldn’t imagine living with the knowledge that we’d left our dogs behind, although we’d do it if we were forced to evacuate to save our children. Merely the thought of making such a choice was so upsetting we could barely talk about it. Our response wasn’t unique to people whose lives and careers are devoted to dogs. My farm’s pragmatic chain-sawing, brush-clearing handyman said that someone would have to shoot him before he’d leave his Rat Terrier behind to die.

What in heaven’s name is going on here? Risking your life for a member of another species? Loving your dog as much as you love a human? That’s flat-out amazing if you think about it. And yet, even if some people think it’s crazy, those of us who love dogs love them like family, or perhaps more accurately, like the family we always wanted.

Surely love, “an intense feeling of tender affection and compassion,” is the foundation of our relationship with dogs. I remember when I got my first Border Collie, Drift. Like an infatuated teenager, I was obsessed with his every move. I thought about him constantly, watched with a sense of wonder as he licked his paws, purred with comfort and completion when we cuddled together on the couch. There are millions of people who feel the same way, whose dogs bring them a unique happiness not found in other relationships.
I’m not talking about people who love animals more than they love people. I’m talking about people who love people, who have enriching, healthy relationships with friends and family and co-workers, and yet who love dogs so much they describe them as one of their greatest joys in life. People who skip having drinks with co-workers after work because their dogs have been alone too long; people who take their dogs on vacation, who use limited funds to buy them toys and food, who borrow money to pay the vet bill. I meet people everywhere who just want to talk about their dogs, about the silly little trick their Cairn Terrier learned all by himself, or the endearing way their Greyhound cuddles with them on the couch.

Our love for dogs is intense, pervasive, and sometimes heroic. If you think about it, it’s as remarkable as the physics of electrons and the wonder of outer space. It deserves our attention, and a good place to start is with the biology of love itself.

The Biology of Love
In a 2005 op-ed piece in The New York Times, the biologist Bernd Heinrich said: “Functionally, I suspect love is often [a] temporary chemical imbalance of the brain induced by sensory stimuli that causes us to maintain focus on something that carries an adaptive agenda.” Doesn’t make you all warm and mushy, now does it? However, Heinrich’s point was not to diminish love’s beauty, but to argue that love has a biological basis, and that there’s no reason to believe that we can claim it as uniquely human.

Oxytocin also plays a significant role in other kinds of love—familial, romantic, and even sexual. Oxytocin levels rise when friends hug, when mothers cuddle their babies, and when lovers have sex. It’s a “one size fits all” hormone, mediating love and attachment in all social relationships that involve feelings of care and connection. Women have higher levels of it than do men, which is not surprising, given oxytocin’s role in childbirth and lactation. Social animals have higher levels of it than solitary ones, a fact exemplified in two species of small mouselike animals called voles. The females of one species, which is highly social, have high levels of oxytocin, while, in the other, downright unsocial species, the females have exceptionally low levels. In people, higher levels of oxytocin correlate with higher levels of attachment and connection. Researchers have even found that spraying oxytocin into the nasal passages of human subjects doubled their tendency to trust others in a “game” that involved giving over custody of their money. In the not-too-distant future it will be wise to steer clear of blind dates with nasal spray bottles.

The central role of oxytocin helps explain why some people, and some dogs for that matter, seem to be more loving and nurturing than others. Individuals vary in how much of the hormone they produce and how effectively they can utilize it when it’s circulating. Individual experience can have a profound effect on people’s ability to feel warm and loving toward others, too; one study found that children adopted from neglectful orphanages had lower levels of oxytocin after cuddling with their mothers than normal children did. However, remember that the impact of experience is constrained by the brain and the body it acts upon. Just as a painter can only work with the canvas and colors she has in front of her, so the effect of experience is influenced by the brain that absorbs it. I often wonder about oxytocin levels when I meet a dog whose aloof behavior breaks her owner’s heart—does the dog have low levels of oxytocin, owing either to genetics or to early development? At present, I know of no one who is using oxytocin therapeutically (except for medical conditions relating to birth and lactation), but perhaps someday we’ll be able to spray stand-offish dogs with oxytocin and turn them into social butterflies.

Love’s Perfect Storm
Oxytocin and dopamine may help us understand the biology behind our strong feelings of attachment, but it doesn’t explain why members of one species—ours—should be so ready to lose their hearts to a member of another species. Not only that, but why dogs? Of all the animals on earth, why is it dogs who have settled into our hearts like rain on the desert? Just sitting in a room with a dog can decrease your blood pressure and heart rate. Petting your dog makes oxytocin flood your body and increases the frequency of brainwaves associated with feelings of peace and contentment. Dogs can even elicit positive responses from emotionally damaged people when the best efforts of family and doctors have failed. Every group that takes dogs to nursing homes has its own story about an unresponsive patient who opened up for the first time in years after petting a dog. But why? Why are dogs such masters at working their way into our hearts as no other animal can?

The traditional answer to the question of why we so love dogs is that they give us “unconditional love” or “nonjudgmental positive regard.” To a large extent, this rings true. The cheerful, loving nature of most dogs brings us a purity of emotion hard to find anywhere else, no matter how much we want it. But I think we need to address this question in more depth. Perhaps our love for dogs, and their love for us, is too complex to be explained by any one factor. It seems most likely that, at its best, the special bond we have with dogs is the result of a number of things, combining together into a “perfect storm” of love and devotion.

First, as we’ve already seen, the faces of dogs are remarkably expressive, and many of their expressions are similar to ours. More than any other animal except our own children (and possibly chimpanzees), dogs wear their hearts on their sleeves. The faces of dogs are like living, breathing, fur-covered emotions, with none of the masking and censoring made possible by the rational cortex of mature adult humans. The expressiveness of dogs gives them a direct line to the primitive and powerful emotional centers of our brains, and connects us in ways that nothing else ever could. When we look at dogs, we’re looking into a mirror. That they express happiness so well, and that happiness is contagious, is just icing on the cake.

Second, the sociability of dogs is similar in many ways to that of humans. Dogs evolved from one of the world’s most social species and naturally seek companionship. That’s why sheep-guarding dogs stay with the flock, that’s why some dogs form friendships with horses that last a lifetime, and that’s why your dog is waiting at the window when you drive home from work. Dogs will live alone if they have to, but as long as there are enough resources to go around, dogs will always choose the company of others. This is as true of adult dogs as of puppies. In many other species, the young can form strong attachments to others, but once they’ve matured, their interest in forming new bonds decreases. Not so dogs—you can become best friends with an older dog in just days or weeks, so strong is their desire for companionship.

Although dogs cling to any kind of social relationship, they don’t treat humans as any port in a storm. They seem to be as attracted to us as we are to them. Even dogs who’ve been socialized for only minutes as puppies are able to form strong attachments to people. (Usually, however, only to a small group of highly familiar people; they remain uncomfortable around strangers all their lives.) By contrast, wolves must be taken away from their mothers at three weeks and raised by humans to be comfortable around us as adults. And dogs want more than just to hang out with us; they seem to want to understand us, and to want us to understand them. They watch our faces all the time for information, just as humans do when they’re unsure of what another person is trying to communicate. You can see people do the very same thing, in a game that dog trainers play to sharpen their skills. One person uses a clicker to train another to perform some action, in a kind of “warmer/colder” game. No words or visual cues are allowed; there’s just the sound of the click to tell the trainee that she’s on the right track. Yet even though trainees are told they’ll get no other information, they turn to look at the face of the trainer when they become confused. Dogs do exactly that when they’re confused about what we want: herding dogs will break their focused stare to turn and look at their handler’s face with the visual equivalent of “What?!” Dogs might even be better at decoding certain types of human signals than our closest relatives, chimpanzees. In some studies, chimpanzees, even ones familiar with people, weren’t able to locate hidden food if the experimenter pointed to it. Subsequent studies on dogs suggested that they were more adept than our closest relatives at the task.

A dog’s desire to communicate with people fits within the bounds of a dog’s evolutionary baggage, in which pack members hunted together, raised their young together, and fought to the death to keep the group together. You can’t coordinate your efforts as a group without some kind of communication, so it’s no wonder that dogs are as obsessed with social communication as we are. But dogs’ desire and ability to communicate, and their formation of attachments, transcend species boundaries. Research found that in novel environments, kenneled dogs were calmer in the presence of a human caretaker than with a dog they’d been kenneled with for over two months. It’s remarkable that an animal would choose an individual of an entirely different species for comfort and companionship. Imagine being lost and alone in the jungle and stumbling upon a person and a bird—and bonding with the bird and ignoring the person. In one study, dogs living in shelters formed attachments to people after only minimal contact. It took only three ten-minute sessions of petting for dogs to become attached, and for the dogs to stand at the door, waiting, if the person left the room.

Some explanations of dogs’ attachment to humans are not particularly romantic. Psychologist John Archer argues that dogs are simply social parasites, who have learned to manipulate our emotions so as to obtain free food, safety, and, in some cases, appointments with certified canine massage therapists and animal communicators. Lord knows dogs are an evolutionary success story: just compare the numbers of dogs in any given country with the number of wolves. However, the biological success of dogs doesn’t negate the profound feelings of love and devotion that go along with it; we don’t dismiss the love of parent for child simply because it’s to the parent’s advantage to pass on his or her genes. I think it’s shortsighted—sad, really—to dismiss the love that dogs have for us in such mechanistic terms.

Still, there is an important truth to be found in an objective view of our relationship with dogs. Painful though it might be, we need to re-examine the belief that dogs give us unconditional love. There’s no question but that most of our dogs love us, and there’s little doubt that, sometimes, their love is often almost epic in its intensity. However, the chance that our dogs are never irritated with us is slim at best. How convenient, then, that they can never say so.
You may wish with all your heart that you could talk to your dog, but as we’re often reminded, we’d better watch out for what we wish for, because we just might get it. The power of speech is a wonderful thing, but it comes with a price. It’s not true that “sticks and stones may break my bones but words will never hurt me.” We all know that bruises and cuts often heal faster than the damage done by a cruel com¬ment. Personally, I’m glad my dogs can’t nail me with the kind of hurt¬ful remark that can come out of the mouths of even the kindest of friends. I’m quite sure that sometimes I’d rather not know what my dogs had to say. I’m reminded of the “words” of Washoe, a chimpanzee raised by Beatrice and Robert Gardner, who ordered trainers she didn’t like out of the room with the American Sign Language for “You green pile of poop.”

We might yearn to tell our dogs why they can’t go on a walk while their injured foot heals, or to explain that we’re only leaving town for a couple of days, but I doubt that we’d have the pure, uncluttered connections we now enjoy if the relationship were burdened by language. In The New Work of Dogs, Jon Katz tells a story about a man who loved his dog because the dog was the only individual he didn’t have to talk to. Katz suspects that men often love dogs because dogs never ask them to talk about their feelings. Women love dogs so much, he suggests, because they see them as being so supportive. A study reported in The New York Times found that half of the female veterinary students surveyed said they got more emotional support from their dogs than they did from their husbands. Surely our perception that dogs are supportive is bolstered by the fact that they can’t tell us to shut up when we’re talking too much. The fact is, some dogs probably do give us unconditional love, but not all dogs do, and most dogs don’t every minute of every day. It just feels that way, given their expressiveness, their childlike cheerfulness, and bless it, their inability to communicate in words. Overall, it seems that what we can’t say to dogs is a small price to pay for what we gain from our wordless style of communication.

As if emotionality, expressiveness, a high degree of sociability, and the inability to tell us to shut up weren’t enough, there’s another important factor that influences our devotion to dogs. We humans have evolved to be protective and nurturing to big-eyed, dependent young mammals, and dogs elicit this state of mind from us with a force stronger than any hurricane. Like young children who stimulate our feelings of nurturance, dogs are nonverbal and have limited abilities. They can’t go to the store and buy food; they can’t open the door and let themselves out. If we left for work one day and never came home, they’d die, trapped and alone and unable to take care of themselves. In these ways they are the exact equivalent of young humans—nonverbal and dependent, wrapped in a fluffy, fuzzy package that says “I’m cute and cuddly and I need you.”

Our feelings of parental love and nurturance are not to be sneezed at; they’ve kept primates like us going for millions of years. The parents of many animals walk away without a care once the eggs are laid or the sperm is transferred, but we shower our young with attention and care over a prolonged period. Lions may raise their young with affectionate licks and cuddles, but they’ll walk away and let their babies starve to death to save their own lives. Not so humans, dogs, or wolves: we’re obsessed with raising, nurturing, and protecting our young, and we’ll sacrifice our own lives to save theirs. Just the sight of young, helpless mammals can change our internal hormonal balance and increase the amount of oxytocin in our bloodstream. Although our complicated brains enable us to be rational and creative, underneath that complexity are ancient structures that generate primal reactions to big-eyed, fluffy mammals. As the writer and behaviorist Karen London so aptly said, “Dogs, the source of so much pure joy and warm comfort, are a reminder that perhaps the passion in our lives is too great to be contained within the bounds of humanity.” There’s great truth to that, and it’s based not on some neurotic need to replace our feelings toward people with feelings toward dogs, but on a deep-seated biological drive to nurture small, dependent things.

So there you have it, a perfect package of love, an animal whose looks and behavior leave many of us weak in the knees. Dogs elicit the love and the desire to nurture that we’re designed to feel toward young dependent mammals, and their expressiveness just ups the ante. The mere sight of them bathes us with the hormones associated with love and devotion. At the same time, sometimes accurately, sometimes not, we feel from them the kind of love we want from our parents, that no-holds-barred, “unconditional” love that psychologists tell us we’ve all been seeking since infancy. It’s a double whammy of epic proportions—we love them like children, and at the same time feel loved by them with the kind of pure, primal love that we needed when we were babies ourselves. Wow. Dogs get us coming and going. In truth, we’re the ones who are helpless.

From For the Love of a Dog by Patricia B. McConnell, PhD. Copyright © 2006 by Patricia B. McConnell, PhD. Published by arrangement with Ballantine Books, an imprint of Random House Publishing Group, a division of Random House, Inc.

“If you want a good dog, get a male. If you want a great dog, get a female and cross your fingers.” That old saying has been passed down through generations in a variety of fields from retriever training to sheepdog handling. But is it true? Are there significant sex-related differences in the training and performance of the domestic dog? When the editor of Bark asked me that question, I had an answer right away: “I don’t know.” Trying to find a legitimate answer began a fascinating quest, which continues to this day.

The first obvious source for an answer is the annals of research. Ah, but it’s only recently that the dog has migrated from persona-non-grata status in science to an animal of interest. Research on domestic dog behavior is blossoming, but most of it is about cognition and problem solving. That’s great stuff, but it won’t necessarily answer our question. I opened up my file labeled “Very Cool Dog Research” and looked at the studies within to see if any of the researchers had considered the sex of the dog as a factor. Nope.

Then I went back to the classic Genetics and the Social Behavior of the Dog by Scott and Fuller, first published in 1965. They found sex differences in weight gain (males, not surprisingly, growing larger in early adolescence), but concentrated primarily on breed differences, rarely looking at sex as a factor in any of their experiments. They did ask if sex had an influence on what they called “emotional reactivity.” Based on their scoring system, females averaged 5.0 and males 4.9—in other words, no difference at all. (See Scott and Fuller for an explanation of their scoring and statistics.)

At the same time, I put the question out into the universe, querying a group of certified applied animal behaviorists and veterinarians board certified in behavior. I emailed the “Tiger Woods” couple of sheepdog training, Alasdair and Patricia MacRae, and experts in police and military dog training. In my blog,  I asked if trainers thought there were differences in learning and performance between male and female dogs. (I did not ask about intact versus neutered or spayed; more on that later.) The answers were enlightening, interesting and downright amusing.

Here are a few of them:

“Males are softer.”

“Females are softer.”

“Males are more independent.”

“Females are more independent.”

“Males are easier to train than females.”

“Females are easier to train than males.”

I could go on, but you get the idea. Despite these contradictions, I saw some interesting trends. First of all, a great many of the respondents said that, in training and performance, the personality and background of any individual dog were more important factors than sex. Given the disparate opinions summarized above, this is a satisfying and logical statement. Looking back at the dogs in my own life, the two I am most apt to label “stubborn” were a male … and a female. The two who most fit the description “biddable” were a male … and a female. And the two I would call “quickest to learn” were—you guessed it—a male and a female.

Other consistencies in the responses lead to compelling questions in their own right. Many of the answers expressed the belief that males mature more slowly than females, describing young male dogs as “goofy,” “slow to mature” and “less focused than females” in their adolescence. This is an especially interesting observation given that in our own species, girls are known to mature faster than boys. I couldn’t find any veterinarians who knew if this was also true for female dogs, but it doesn’t seem unreasonable.

Another contrast drawn between males and females was that male dogs perform better in certain types of competition. From herding to Schutzhund to retrieving, whether we like it or not, they dominate the winner’s box. Based on their names, 12 of 15 winners of the last 15 years of International Sheepdog Trials were male and two were female (one could have been either). Since 1990, 19 dogs have won the U.S. National Open Retriever Championships. Sixteen were male, two were female, and one is still “unknown” (to me that is; I’m sure someone knows!). This trend is replicable in many of the highly competitive performance sports, especially those that involve large sums of money.

It is challenging to tease out why that might be true. One logical explanation has nothing to do with the ability or competitiveness of either sex. Dog-related sports like herding and retrieving involve a lot of money, and in almost all of them, intact, potentially breeding males and females compete, never neutered or spayed animals. (This raises a complication not addressed in the original question—when we say males, are we talking intact breeding males, or neutered males? Given that there is so little real data on the question of gender, we’ll have to leave this aspect aside for now, but it is important to acknowledge that intact versus neutered could be an important factor.)

If you are running intact animals, as almost all high-powered handlers do in competition, the sex clearly has an effect on which sex you’re going to invest in. You can’t run a female when she’s in heat, and neither is it wise, or ethical for that matter, to run a female when she’s in the latter stages of pregnancy or nursing a litter. Who wants to invest large amounts of time and money in a performer who can do her job only half the time?
In addition, many competitors breed and train their dogs for a living. Say you own more than one top-notch performer. You will surely ask yourself which animal could best support your kennel and buy the dog food—a male who can be bred several times a week for a hefty stud fee, or a female who might produce one (regrettably, sometimes two) litters of puppies a year?

Another explanation is that there is indeed something about a male dog that makes him more competitive under pressure. Testosterone is a powerful drug, and we know it has broad-ranging effects on assertive and aggressive behavior in species as different as rhesus macaque monkeys and mallard ducks (not to mention traders on the stock market, who are more successful if they have longer ring fingers than middle fingers—which is believed to correlate with the production of male hormones in utero. No kidding.)

There’s another possible influence on the behavior of male and female dogs, but this time it relates to our behavior. How much of our demeanor around dogs is based on our expectations of “maleness” and “femaleness”? I don’t know about you, but if I’m honest about it, I find myself strongly influenced by the sex of a dog. I’m not aware that it affects the way I train—I believe that, with good training, individuality trumps sex or breed differences—but I’m sure it influences my perceptions of them in general. Perhaps unconsciously, it has a significant effect on my behavior, and on the behavior of all of us with cultural expectations of how males and females are supposed to behave.

But are these expectations based solely on culture? Or is some of a dog’s personality determined by his or her gender, as with the obvious sex-related behaviors like scent marking, roaming and interspecies conflict? Call me crazy, but I can’t help but believe there is something inherently different about male and female dogs that is not just a misplaced human attribution, and that goes beyond the obvious differences. My soul mate dog Cool Hand Luke seemed so male to me that I simply can’t imagine him as anything but a—well, a guy. My “real” guy Jim felt the same way too, admitting to a tiny bit of jealousy when we first started dating, an emotion he never felt around my other three dogs, all females.

Now I have two dogs, Willie, who is one of Luke’s nephews, and Lassie, Luke’s 15-year-old daughter. I simply can’t imagine thinking of Willie as a female, or Lassie as a male. But why? Is this based on any actual sex-related differences in their behavior, or on my culturally imposed expectations? We know that expectations can have profound effects on behavior in our species. Surely it could be true of dogs as well.

You see how complicated this issue can become. (And I pose only a few of the questions that this issue raises—as in “What do you mean, ‘easier to train’? Quicker to associate a sound and a behavior? More consistent once the behavior is first learned?” and the like.)

Here’s what I do know. This is a topic that calls out for research. Dogs are finally coming out of the woodwork as interesting and important in our search to understand the biology of behavior, and this is a perfect vehicle for study. What’s shocking is that we know so little about canine behavior, and what’s exciting is that there is so much to learn. I remember being a freshman in college, sitting in an introductory biology class and thinking, literally, “Oh gosh, everything has been discovered already.” Less than a year later, I had changed my tune, having learned how much we don’t know, and how much new is discovered every year. That’s as true of canine behavior as anything else, and I am thrilled that dogs are finally getting the attention they deserve. For example, Dr. Anneke Lisberg just completed her PhD from the University of Wisconsin on scent-marking behavior in dogs, a topic we know shockingly little about. Dr. Camille Ward completed her University of Michigan dissertation last year on social development and play behavior in puppies. These are but two examples of the kind of rigorous science-based studies that dogs deserve. But we need more, lots more, and I hope the trend of investing time and resources into the study of canine behavior continues to gather steam.

Meanwhile, make your own observations about your dog’s behavior. Do you see differences between males and females related to training and performance? Do you relate to your dogs differently based on whether they are male or female? We’d love to hear what you think; give us your opinion. Meanwhile, back at the farm, I’ll ask Ms. Lassie and Mr. Will their opinion. (Yeah, okay, I really do call them that. Oh my.)