Two out of three American households keep an animal primarily for companionship. While these housemates may have scales, fins, fur, or feathers, people often view them as part of the family. In fact, in 2019, we spent an estimated $95.7 billion on our pets … not to mention untold hours caring for them.
For over 50 years, psychologists have been trying to understand the appeal of animal companionship. In the process, anthrozoologists—scientists who study human-animal relationships—have discovered a window into human sociality more broadly. It turns out our interactions with animals can be useful models for understanding how issues of identity, nurturing, support and attachment play out in other relationships.
As anthrozoologist Pauleen Bennett of La Trobe University in Australia explains, “It’s all about human psychology. Pets help us fill our need for social connectedness.”
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Although our motivations for pet ownership may vary, scientists are finding some common threads that tie people to their household pets. From goldfish to Golden Retrievers, our attraction to animals may be driven by biological and social forces that we don’t consciously acknowledge. Plus, the emotional bond between pets and their owners can bring various benefits, from lowered stress to novel adventures.
Part of our attraction to animal companionship is innate. Psychologist Vanessa LoBue of Rutgers University and her colleagues have revealed that, when given a choice, toddlers spend more time interacting with live animals—whether fish, hamsters, snakes, spiders or geckos—than they do with inanimate toys.
Humans even have specialized brain cells for recognizing animal life. Researchers led by Christof Koch [kɑːx] of the Allen Institute for Brain Science in Seattle have found neurons in the amygdala, an area involved in emotions, that respond preferentially to animal images. Their finding hints at a neural basis for our powerful emotional reactions to animals.
Many animals also seem to tap into humans’ attraction to the adorable, which may help motivate good parenting. Behavioral researchers have long noticed that humans seem to have inborn, positive responses to creatures with characteristics typical of human infants—such as wide eyes, broad foreheads and large head-to-body ratios.
To better understand our responses to cuteness, in 2012 psychologist Hiroshi Nittono, then at Hiroshima University, published a series of experiments in which 132 college students had to either search for a digit in some numerical matrices or lift tiny objects from small holes using tweezers. The students then viewed a series of photographs before attempting the attention or motor task a second time.
Nittono and his colleagues found that students who viewed adult animals or food—stimuli they rated as pleasant but not cute—did not improve between trials. But the students who saw cute baby animals performed the tweezer task faster and more dexterously and completed the visual search task faster the second time.
This finding suggests not only that being exposed to such creatures motivates focused, attentive behavior, but also that humans are primed to attend to fragile, young infants, who require a great deal of care. So, it seems baby animals elicit the same instinctive responses in us that our own infants do.
Such findings lend credence to the idea that our interest in pets stems from what biologist E. O. Wilson has called “biophilia,” or an inherent tendency to focus on life and lifelike processes. Our fascination with all manner of fauna might explain why people adopt such a wide range of animal life, from tarantulas to salamanders.
Yet Wilson has also acknowledged that our interest in animals depends on personal and cultural experience. For example, dogs might be popular in many Western countries, but they’re actually considered unclean in traditional Islamic communities.
Indeed, psychologist Harold A. Herzog of Western Carolina University has argued that pet keeping is driven principally by culture. Herzog and his colleagues assessed the fluctuating popularity of dog breeds using the American Kennel Club’s registry from 1926 to 2005. They found no relationship between a breed’s health, longevity or behavioral traits such as aggressiveness or trainability and its popularity. Instead, they found that the trends in top dogs seemed to shift suddenly, as if driven by fashion.
Three of the authors, including Herzog, further discovered that movies featuring specific dog breeds would boost that pooch’s popularity for up to a decade. In the 10 years following the 1963 release of The Incredible Journey, which starred a Labrador Retriever, people registered Labs in the kennel club at an average rate of 2,223 a year, versus just 452 a year during the previous decade.
Extending these findings to other species, Herzog argued that people may keep pets simply because others do. As further evidence, he pointed to a brief turtle craze in the U.S., a koi fish fad in Japan and what he jokingly identified as a short-lived “epidemic of Irish Setters.”
But even if imitation plays a role in their choices, most people still say they want pets for companionship. This friendship then sustains the connection despite the costs of ownership. In fact, some animal-human relationships feel similar in certain ways to human relationships.
In a study published in 2014, Massachusetts General Hospital veterinarian Lori Palley [Pal-lee] and her colleagues used functional magnetic resonance imaging to measure brain activity in 14 mothers while they were looking at pictures of their children or their dogs, or at pictures of other people’s children or unfamiliar dogs.
The researchers found that the brain activation patterns evoked by images of the women’s own children and dogs were very similar and that those patterns were distinct from ones elicited by unknown children and canines, suggesting that maternal feelings may extend to animals. So, pets may actually help fill a human need to nurture other living beings.
An animal can also be on the flip side of this relationship, serving as a source of comfort. In the 1960s Yeshiva University child psychologist Boris Levinson observed that troubled, socially withdrawn children became talkative and enthusiastic about therapy when his dog, Jingles, was present during a session.
This observation spurred a series of investigations into whether or not keeping pets could improve well-being, many of which have shown there are benefits to having a pet, from stress relief to psychological support to emotional sustenance.
Different hormonal cocktails seem to underpin various degrees of animal-human attachment. In a study published in 2012, biologist Linda Handlin of the University of Skövde in Sweden and her colleagues measured levels of the bonding hormone oxytocin and stress hormone cortisol in 10 owners of female Labrador Retrievers and correlated the results with self-reported data about the owners’ relationships with their dogs.
Owners who had higher oxytocin levels and lower cortisol levels when interacting with their dogs tended to have closer bonds with their pets. People who frequently kissed their dogs, for example, had higher levels of oxytocin, and women who reported that they dreaded their dog’s death had lower cortisol levels, perhaps because they rely on their animals for stress relief.
And psychologist Andrea Beetz of the University of Rostock in Germany and her colleagues have found that interacting with animals may be an especially good buffer against stress for those who find human social interaction difficult.
“Some things are much easier with animals,” Beetz says. “They are easier to forgive, don’t talk back, and there’s less inhibition when it comes to physical contact.”
Yet pets are much more than just human substitutes. Many people with no obvious social deficits reap varied psychological benefits from owning a pet.
A 2015 phone survey of Australian city dwellers found dogs were “social icebreakers”: a puppy can be a great way to meet neighbors.
A small Korean study found that seniors who tended crickets for eight weeks had improved mental states, perhaps because the responsibility gave their routine added meaning.
In 2012, Pauline Bennett presented preliminary findings from a student, psychologist Jordan Schaan, who’d interviewed 37 dog owners who were personally and professionally successful and had an above-average connection to their animals.
Among the benefits of dog ownership this group reported was amusement; the animals’ antics made their owners laugh.
Plus, many pet owners described their companion animals as instructors in a simpler, more virtuous lifestyle. Bennett and Schaan discovered that their highly successful subjects actually looked to their dogs as role models for a better life. People felt they could derive unconditional love and forgiveness from their dogs, whereas human beings seemed more likely to disappoint one another.
“There’s something about animals that’s very genuine and honest,” Bennett says. “We miss that in our human interactions.”
Bennett and other anthrozoologists acknowledge that owners project some of this dynamic onto their animals. An owner can “read” a response into an animal companion’s behavior regardless of the animal’s intentions. But such projections are precisely what make this field ripe for psychology: they reveal our own social needs and desires.
Animal relationships may someday provide useful comparison points to human connections—a benchmark for investigating empathy, caring and even decision making. That these creatures can fit many molds while being so different from us makes these friendships uniquely valuable.
Reference: Pets: Why Do We Have Them? Daisy Yuhas in Scientific American Mind Vol. 26, No. 3, 28-33; May 2015. doi:10.1038/scientificamericanmind0515-28. Republished 2018.
