Americans are voracious pet keepers. Roughly 70 percent of American households have a pet, and half of those own two or more. Americans keep over 94 million cats, 89 million dogs and 20 million birds. Over 11 million households have freshwater fish, and nearly seven million have small animals such as hamsters, gerbils, rabbits, guinea pigs, chinchillas, mice and ferrets. Americans are expected to spend more than $35 billion on veterinary care in 2024, plus another $58 billion on pet food and treats—twice the amount in the mid-1990s.
Pet keeping is not a new phenomenon: cats and dogs accompanied Europeans to the American colonies not only as work animals but as companions. By the mid-18th century, colonists had begun to keep birds and rabbits in their homes.
Cats were called Puss and parrots Polly as early as the 16th century; the international bird trade began in the 1840s; the first packaged pet foods and commercial medicines also appeared in that decade; an aquarium craze took place in the 1850s; and the first dog show took place in the 1860s.
Pet toys became popular during the 1920s, and surgical spaying of pets became common during the 1930s. Especially striking is the proliferation of breeds of dogs and cats. Until the early 1900s, family dogs consisted of a narrow range of types: spaniels, hounds, setters, pointers, terriers, mastiffs and bulldogs.
The appeal of fish, which became popular in the 1840s, was primarily aesthetic. In contrast, the attraction of caged birds was as much ideological as aesthetic. According to Katherine C. Grier’s authoritative 2006 history, Pets in America, this was due to “their apparent monogamy and devoted parenting.” Birds were considered “natural models for middle-class family life” and “living examples” for children, while their chatter and music helped to overcome the silence of homes in the days before phonographs and radio.
Pet keeping assumed heightened significance as social life grew increasingly impersonal and adversarial. But Grier also suggests other reasons for the heightened interest in pet keeping during the post–World War II years—above all, the view that pets contributed to children’s development by teaching them about love, loyalty and responsibility.
Today, many young adults keep pets for companionship, emotional support and social connectivity at a time when loneliness and social isolation have become mounting concerns. For some, pets are an extension of their identity and a way to express their individuality and values, such as compassion and caring. With marriage and childbearing delayed, pets can be a way for young adults to nurture and care for a living being. In addition, pet keeping can encourage physical activity through walks and play, contributing to a healthier lifestyle, while the routine and responsibility of pet care can provide a sense of purpose and structure, which is beneficial for mental health.
Pet keeping offers a vivid window into a profound shift in changes in the human relationship with the natural world. As the eminent English historian Keith Thomas observed in a classic 1983 book, between 1500 and 1800, “New sensibilities arose toward animals, plants and landscape. The relationship of man to other species was redefined; and his right to exploit those species for his own advantage was sharply challenged.”
The trend toward treating animals as integral family members deserving of special care and affection is a product of a prolonged history. The animal-human connection, of course, dates to prehistory but was, for centuries, linked to a human impulse to dominate the natural world. We currently believe that humans began to domesticate animals during the Neolithic period, approximately 10,000 to 12,000 years ago. Reasons varied but included provision of a reliable food supply, as well as resources including wool and leather, assistance in agricultural tasks, and commodities for trade. Over time, humans selectively bred animals for specific traits, such as docility, productivity and size.
The domestication and selective breeding of many nonhuman animals often involved a process called neoteny, or juvenilization—the imposition, retention or reinforcement of immature characteristics. This apparently served as a horrific ideal for slave owners, who sought, without success, to juvenilize their slaves. In England, meat eating was often taken as evidence of human superiority on the great chain of being and as a way to ingest the animals’ strength and fortitude.
It was between the early 16th and the late 18th centuries that “a conviction of man’s ascendancy over the natural world gave way to a new concern for the environment and sense of kinship with other species.” Nothing better illustrated that shift than a growing interest in pet keeping. Increasingly, animals were given human names, included in family portraits and, among the English elite, better fed than servants. There also arose an unprecedented concern with the extinction of species.
Instead of viewing nature as something that should be subdued, civilized and exploited, it was to be conserved. At the same time, new attitudes toward nonhuman animals arose. Sensation was ascribed to fauna, especially among those who didn’t interact with animals on a daily basis.
Thomas argued that English attitudes toward fauna before 1500 were heavily influenced by theological beliefs. Scriptures depicted God as creating every animal and plant primarily to benefit for work and sustenance and be under the control of humans. Animals were widely regarded as soulless automatons, without consciousness and guided by instinct rather than thought or emotion. Classical thought, from Aristotle onward, regarded humans as distinct and superior to other animals due to their unique capacity for reason.
Malevolent spirits were frequently depicted as animals, with the devil himself often represented as a goat. Human physical desires were disparagingly compared to animal instincts, to be mastered and controlled. English society also applied animalistic labels to outsiders and non-Christians, deeming them less than human and in need of civilization.
Over time, the scientific study of the natural world threw those earlier ideas into question. Naturalists shifted the focus from the utility of plants and animals to studying them for their own sake. Meanwhile, artists increasingly celebrated the beauty in nature, asserting that nature had its own intrinsic value, independent of human utility.
Well before Darwin, geologists extended the known history of the earth, giving credibility to the idea that humans had evolved from earlier species. Even though Enlightenment racial typologies position Europeans at the apex of creation, the belief that fauna (as well as non-Europeans) lacked an immortal soul eroded.
Darwinian evolution has dramatically altered the way humans perceive their relationships with other animals. By establishing a biological continuity among all species, it has fostered a deeper appreciation for the complexity of animal life and a re-evaluation of human exceptionalism. This paradigm shift has had profound ethical, scientific and environmental implications, reshaping our understanding of animals from beings of utility or inferior status to fellow inhabitants of a shared evolutionary journey.
Without doubt, humans and nonhuman animals differ in important biological, cognitive, behavioral and cultural respects. There are differences in brain structure, especially in areas involved in language, abstract thinking and problem-solving. Bipedalism, manual dexterity and fine motor skills are other axes of difference.
In addition, humans have a highly developed larynx and vocal cords capable of producing a wide range of sounds, facilitating complex spoken language, which is not found in other animals to the same degree. Human possess complex language skills that enable symbolic thinking, nuanced communication and the ability to convey abstract concepts. Humans also appear to differ in the nature of self-awareness. Humans demonstrate a well-developed ability to reflect on their thoughts and actions, awareness of their mortality, and understanding of their role in society, as well as highly developed systems of ethics, including concepts of altruism, justice and rights, to guide behavior.
Other distinctions include the profound human impact on the environment through such as agriculture, urbanization and domestication of other species and the ability to inhabit diverse ecosystems and adapt to a wide range of environmental conditions.
On the other hand, there is evidence that some animals, including meerkats, dolphins and whales, and ants, exhibit teaching behaviors; engage in basic food preparation and processing; and communicate using a variety of sounds, gestures and signals. Also, it’s clear that certain species have capacities that humans lack, such as echolocation in bats and dolphins, the ability among bees and butterflies to see ultraviolet light, or dogs to hear higher-pitched sounds or elephants to hear lower-pitched sounds.
While it has proven challenging to ascertain nonhuman animals’ level of consciousness or their subjective experience of pain, it is clear that many nonhuman animals have significant cognitive abilities. Elephants show empathy, crows use tools and octopuses exhibit problem-solving skills. Primates, dogs and even rodents display behaviors suggestive of emotional lives. Complex social structures abound within the nonhuman animal world.
Yet it would be a mistake of the highest order to reduce the shifting relationship between humans and the natural world to a story of onward and upward progress. True, there are signs of a shift in outlook, evident in a growing awareness of animal sentience and a growing concern with animal welfare and advocacy for animal rights. There is, without a doubt, a deepening sense that nonhuman animals should be shielded from torture and abuse and have a right to live in a natural environment.
To take some gruesome examples that seem to illustrate progress: before the 20th century, it was common for pet owners to personally drown newborn kittens or puppies that they could not care for and for strays to be strangled with wire lassos or clubbed or shot on the spot. Today, in stark contrast, it is far more likely than in the past for people to share a bed with a pet or to hold pet funerals or hang posthumous portraits of their pets or to inter pets in animal cemeteries, replete with grave markers.
It is, of course, possible to trace a growing ethic of kindness toward animals, from the enactment of the first statutes against cruelty to animals (as early as 1828) to the establishment of societies for the prevention of cruelty to animals in the 1860s and the proliferation of books featuring anthropomorphized animals, especially virtuous, faithful and loving dogs, in the 20th century. Other signs of an intensified engagement between owners and their pets can be seen in the rise of veterinary practices specializing in small animals during the 1930s, along with an expanding array of pet care products.
Yet it is also possible to view the history from a far more critical vantage point. The American Society for the Prevention of Cruelty to Animals estimates that over six million strays, animal surrenders and animals seized due to cruelty and abuse enter into animal shelters each year. Around 1.5 million shelter animals (670,000 dogs and 860,000 cats) are euthanized annually (down from 2.7 million in 1997, due to spaying and neutering and increased adoption rates). If some pet keepers are strongly attached to their pets and are willing to spend large sums on training or medical care, many others are willing to give them up due to inconvenience, the cost of maintenance, old age or illness, or refractory behavior.
Meanwhile, there is evidence that pet owners have grown less willing to tolerate “animal-like” behavior. Declawing has grown more common. Meanwhile, an obsession with purebred, pedigreed animals, which began in the 1870s and accelerated after 1940 (and often promoted with language that echoed the early-20th-century interest in eugenics and racial purity) resulted in animals suffering from orthopedic defects, congenital heart problems and thyroid disorders.
What is the contemporary American relationship to animals? Are pet owners truly stewards of domestic animals or do they, instead, focus primarily on the emotional or aesthetic pleasure that the pets bring to themselves? A majority of pet owners regard their animals as friends or family members and grieve deeply when a pet dies. But few would consider treating a friend or relation the way they treat their pets.
Today, many pets are overdomesticated and overcontrolled. It is cruel to expect a dog or cat to remain in a house or apartment much of the day without anyone to interact with. Americans may profess to love their pets and certainly spend a great deal of money on them. Some apparently regard their pets as child substitutes. But there is extensive evidence to suggest that many pet owners are unwilling to meet the animals’ needs for companionship, interaction and freedom.