Most humans would agree that we share some very special relationships with nonhuman animals. The relationships we have with our companion animals such as dogs as well as horses are often rooted in strong emotional bonding and attachment(1). Research has shown that this attachment bonding is actually quite similar to what occurs between humans, but, of course, is also very unique. By deepening our understanding of these bonds, we can determine how to become better animal guardians.
Humans not only invest emotionally in companion animals, but also financially, with the amount of money spent on them increasing with each year(2). These emotional and financial investments illustrate the depth and importance of what scientists have begun to call the human-animal bond. More researchers are examining this phenomenon in their work and have found that this bond benefits humans in a number of ways, such as enhanced psychological well-being and even aiding in recovery from illness. In one study, pet ownership was found to be associated with lower levels of depression in elderly individuals who had little to no social support, likely due to the fact that the human-animal bond allows for a sense of social relatedness and belonging.
These special relationships began thousands of years ago and have transformed throughout the years. Horses began appearing in cave art as early as 30,000 years ago(3). These Paleolithic humans likely hunted them for meat. Recent archaeological evidence tells us that the domestication of modern horses began approximately 6,000 years ago in the steppe lands north of the Black Sea(4).
Unlike most other domesticated large animals, which are mostly kept for breeding, meat production, milk production, etc., horses acquired a mixed status: they are a source of food for some, for leisure and sport for others, or, less frequently, an agricultural working companion in rural areas(5). In more recent years, horses and horseback riding are being utilized as forms of therapy. These include equine-facilitated psychotherapy, equine-facilitated learning, hippotherapy and also, more generally, therapeutic riding. Horses are also simply companions, and there is no doubt that a long-term bond forms between owner and horse. Horses have become very sensitive to our communicative signals, but some horses understand visual and auditory cues better than others(6). Research has shown that horses respond to even the most subtle human eye and body movements.
Lindsey Culver of Longmont, Colo. believes much of what is said about the human-horse relationship is true for the bond she shares with her miniature donkey, Emma(7). Emma was terrified when Culver rescued her last year, but after a few months, Emma began to become more and more affectionate. “When we first got her, she wouldn’t even come near us. We definitely couldn’t touch her. So, we just worked with her to gain her trust, and now she’ll just let us pet her all of the time,” said Culver. Culver and Emma have developed an exceptional bond. “Emma is really in tune with how I’m feeling when I’m with her.”
Perhaps the most fascinating human-animal relationship is found in the incredible bond we share with our dogs. There is still much mystery regarding the origins of the relationship between dogs and humans, but it is currently believed that dogs were domesticated sometime between 32,000 and 18,800 years ago(8). The origin and purpose of most other domesticated species’ have been determined, but the evolutionary history of dogs, the first domesticated species, is still debatable. Some scientists are hypothesizing that, at first, the domestication of dogs was not deliberate. One theory is that wolves began following humans to take advantage of the scraps we left behind. Eventually, some of these wolves began to lose their fear of humans, and humans began to lose their fear of wolves. Thus, a mutually beneficial relationship developed in which wolf-dogs would track and immobilize prey, and humans would follow and rapidly finish off the larger animals with their “more advanced technology” (i.e. spears). Then, the humans and the wolf-dogs would share in the spoils. This could have been the beginning of the development of the exceptional inter-species communication that exists between dogs and humans today. Dogs are the most adept nonhuman animal at understanding our communicative signals and are able to understand human pointing gestures better than wolves and even primates, our closest living ancestors(9). Some studies have also demonstrated that dogs can understand where human attention is directed based on the direction of our gaze(10).
In addition to their attention to our gaze, there have been recent studies suggesting that dogs can also recognize human emotional expressions and even pick up on subtle mood changes. One study showed that dogs were more likely to choose objects that their owners handled with smiling faces over objects that were handled by their owners when wearing a look of disgust(11). A more recent neuroimaging study demonstrates that dogs are also capable of picking up on subtle mood changes based off of how their brains processes humans’ emotionally-laden vocalizations(12). If dogs are adept at distinguishing our moods and emotional states as well as our communicative signals, this provides further evidence for the existence of the extraordinary human-canine bond.
Another common companion animal that we share a special bond with is the cat. Based on archaeological evident, cats have shared a symbiotic relationship with humans for approximately 9,500 years(13). In Egypt, over 4,000 years ago, highly revered cats were kept domestically, and there is even evidence that Egyptians administered medical treatment to their cats.
Cats remain an integral part of our families today, with over 80 million cats residing in U.S. homes alone(14). One study found that cats are able to adapt to the personalities of their human guardians, which may contribute to what humans interpret as a close bond with their cats(15). However, one scientist, Dr. John Bradshaw, argues that the bond we share with our cats is different than the bond we share with our dogs, and that cats may not be as behaviorally flexible as some think(16). Dogs recognize that humans are not dogs, as evident by their change in behavior when interacting with another dog compared to their behavior when interacting with a human. However, cats do not--their social behavior with other cats is fairly indistinguishable to how they socialize with humans. While there is a lack of research on the human-feline bond, cats and humans undoubtedly share a special relationship.
Science continues to provide compelling research demonstrating what we already know in our hearts: the existence of the human-animal bond. This information teaches us more than just the history and depth of the human-animal bond, but it also shows us how humans can greatly impact the welfare of our companion animals when we recognize how remarkable these relationships are. Thus, it is critical that we continue to deepen our understanding of this bond; doing so not only has the power to improve our own lives but also the lives of the nonhuman animals we love so dearly.