Psychology of Pet Owners

In our last class, we'll turn the tables and look at the psychology of pet owners: what is it about pets that affects us so?  Please come to class prepared to discuss the relationship you have with your pet; what things they do that affect you and why you think that you respond to them the way that you do.

Introduction

There is a parasite called Toxoplasma Gondii, a protozoan, which infects and reproduces in cats.   Rats which eat infected cat poop become infected, whereby the protozoa travels to the rat's brain.  In the brain the protozoa make changes so that the rat will be no longer fearful, and will not avoid places marked with cat urine.  The rat becomes an easy prey for a new cat, which will become infected upon eating the rat, leading to a renewed life cycle for the protozoa.   Around 6% of cats tested in Virginia were actively shedding toxoplasma oocytes.  Handling of cat feces by humans can lead to infection, called toxoplasmosis, which can have a subtle effect on human behavior, increasing the rates of homicide, suicide,  psychiatric disorders, or severe infection in pregnant women or those who are immunocompromised.  The CDC estimates that six percent of Americans, age six or older have been infected with Toxoplasma Gondii.

There are two other parasites which have much higher prevalence in the United States.  It is estimated that 44.5% of U.S. households own dogs, and 29% own cats.  These parasites take a huge economic toll on American households: the market for pet food is $57 billion and for that of pet veterinary care is $36 billion.  U.S. pet owners spend an average of $1,480 on their dogs and $902 on their cats.   In this chapter we'll explore the reasons that so many Americans welcome these parasites into their homes.

Our Changing Relationship

Until the Victorian era, most dogs were utilitarian: kept primarily for hunting, herding, or perhaps most commonly for protection.   In the 1960's, 25% of the dogs in America were allowed to range freely outdoors, and many more were kept outdoors in dog houses.   In the rest of the world as many as many as 75% of dogs are strays or feral.   As Professor Susan Little explains, in the late 20th century, parasite treatments for fleas, ticks and worms became widely available in America, and we began to welcome our pets into our homes as family members.  A nationwide drive to sterilize pets and keep them indoors has dropped the euthanasia rates of dogs and cats by 90%, from 13.5 million in 1973 to about 1.5 million today.  Today, a third of cats are still allowed to roam outside, but most dogs and cats have made a transition from pets to members of our family.

Physiological Benefits of Pet Ownership

While dogs and cats may be parasites, there's intriguing evidence that they may be beneficial to our health.  A study from 1980 showed that one year after a heart attack, 28% of patients who did not own pets had died, while only 6% of patients with pets died, suggesting a strong protective effect.  The researchers replicated their study fifteen years later, and specifically examined dogs rather than pets in general, and found that dog owners were significantly less likely to die in the year after a heart attack than non-dog-owners, while cat owners  were no more likely to survive than non-owners.  A hypothesis for the physiological mechanism of the cardioprotective benefit of dogs was given by Margo, who pointed the relationship between anxiety, depression, and inflammation, as described in this article.  To the extent that a dog can help relieve anxiety and depression, that, in turn, should reduce inflammation, which can prevent future heart attacks.

These studies sparked a flurry of studies whose results have not been as clear cut.   A 1992 study showed that pet owners attending a free screening clinic had significantly lower systolic blood pressure, triglycerides and cholesterol levels.  Some of the benefit may have been because the pet owners reported having more exercise than the non-pet owners.   Some large studies in Australia showed that pet owners had fewer physician visits than non-pet owners, but other studies failed to confirm the observation.  Several studies have shown that sitting with or petting a dog or cat reduced heart rates and blood pressure, and exposure to a stressful mental or physical event caused smaller increases in heart rate and blood pressure for pet owners.  Part of the problem with these studies is separating out the effects of confounding variables such as age, mental and physical health, and living relationships.  

Psychosocial Benefits of Pet Ownership

The psychological need for pet companions was illustrated during the Covid pandemic when 23 million households, nearly one in five in America adopted a pet.  Between 2016 and 2022, the percentage of U.S. households who own dogs increased from 38.4% to 44.5%, while the percentage of households that own cats increased from 25% to 29%.  People reported that they purchased pets in response to the social isolation from Covid lockdowns.   A book by Robert Putnam, Bowling Alone: The Collapse and Revival of American Community documents the breakdown in American's social fabric and the increasing isolation of Americans.  It may be that companion pets are helping Americans to compensate for reduced social interactions.  But do pets really help lift people's mood?

One literature review found no relationship between the presence of a dog and depressive symptoms among older community dwelling adults.  Another small study found that dog ownership reduced depression for women and individuals who are not married.  A third study showed no correlation between pet ownership and depression but did show slightly lower self-reported anxiety symptoms among pet owners.  A large internet survey showed that unmarried women who live with a pet have the fewest depressive symptoms, while unmarried men who live with a pet have the most.   A hypothesis for the different outcome between women and men, suggested by Ronald, is that women tend to be much more empathetic than men, so perhaps they have a deeper relationship with their pet which helps relieve their depression.   Another literature review showed that pet ownership was related to lower rates of childhood loneliness before COVID, and lower rates of loneliness overall during COVID.  Several studies have shown benefits in mood, positive behaviors and socialization from visiting with animals to residents of nursing homes and people with dementia and other cognitive impairments. 

Part of the psychological benefit of pets may be due to their stimulation of human ties.  A survey suggested that pets can be a catalyst for making friends in their neighborhoods.  Among older single adults, dog owners but not cat owners were less socially isolated than individuals without pets.   Brian Hare described an experiment where a graduate student solicited conversation from strangers, while dressed in different clothes, with or without a dog.  "The best predictor of success? Again, whether the young man had the dog. It did not matter if the dog wore a studded collar or not, or whether the guy looked sharp or like a homeless bum. If the dog was there, the number of people who smiled or talked to him went up by 1,000 percent."  In a different experiment a male experimenter solicited phone numbers from passing women.  When he had a dog sitting by his side his success rate increased from 6% to 28%.  Why do you think that a dog helps to lower the barriers between people?

Explanations for the Benefit of Pets

Why do psychological benefits arise from owning pets?  This Youtube offers some ideas, especially the thought that our pets' sense of living in the moment and enjoying life can remind us to live in the present: "We don’t just own our pets, we love them, we become best friends with them and form bonds that are truly reciprocal and unconditional.  We give them access to consistent safety, health, comfort, and other logistical things that they might struggle to sustain.  They help remind us of a side of ourselves that we want so deeply to live in but often struggle with.  The appreciation for simplicity, the ability to feel free, the obsession with fun, the lack of sensitivity to embarrassment, the disinterest in holding grudges, and the unrestrained affection that our pets possess are all of the things that we long for and wish we could feel constantly in ourselves but often struggle to do.  And our pets embody and remind us of the importance and possibility of those things.  I would argue that the elements of our nature that our pets lack, like complex language, logical understanding, heightened self awareness, etc are all equally beautiful and essential to what makes the human experience so uniquely wonderful.  But I would also argue that it can be very easy to become lost in this part of ourselves: the part that needs to understand and control everything.  And our animal companions help show us that we don’t always need to.  That life can sometimes be best enjoyed by simply enjoying it for what it is.  Feeling it.  Playing in it.  Rolling in its grass.  And so perhaps at the end of the day, even though we may like to think that our pets depend on us, it may be more so the other way around."

Attachment Theory

Starting in the 1970's, child psychologists began to study the importance of attachment theory on infant development.   Many studies on monkeys and observations of human infants and children show the critical importance of a strong bond between infant and its caregiver (often its mother) for the ability of the infant to develop healthy relationships as an adult.  During the first year of life babies avidly solicit attention through smiling, babbling, crying, eye contact, touching and pointing.  Babies require touching and attention for proper development, not just food and water.

While there is a lot of literature on attachment theory in infants, there is much less research on attachment theory as applied to caregivers.  Clearly, since a caregiver bond is essential for normal human development, there must be biological and psychological imperatives for caregivers to respond to infants.  Clearly interest in infants is hardwired; look no further than a room full of people presented with a cute baby.  One mechanism for caregiver bonding that has been studied is the hormone oxytocin, which is released in the brain during lactation amd sex, and seems to be crucial in forming strong bonds with infants, sexual partners as well as with members of ingroups.   But oxytocin is just the tip of the iceberg.  Ours is a hypersocial species and most of us derive great reward from nurturing, helping, comforting, forming attachments to and listening to others.  The various brain mechanisms for these behaviors await further study.

Oxytocin Gaze Loops

Just as the hormone oxytocin facilitates bonding between a caregiver and infant, as well as between members of an ingroup, a study has shown increased oxytocin levels in dogs and their owners who gaze at each other.  Recall that staring by a predator is a very threatening behavior for most animals, and that dogs and cats have overcome the fear response from a human gaze.  In an experiment where humans were directed to either gaze for long or short periods at their dogs, oxytocin levels in both humans and their dogs were significantly correlated with the duration of dog to owner gaze and amount of touching.  In another study measuring oxytocin levels in older women who interacted with their cats, oxytocin levels rose during kissing, hugging and cat initiated affiliative behavior, although not when the cat just purred.

Pet Face

As we studied earlier, dogs and cats are neotenized: through the process of domestication, they retain juvenile appearance and behaviors into adulthood.   Their physical appearance is a main component that allows them to hijack our hardwired caregiver circuits.  As Alexandra Horowitz says, "Finally, they are compellingly cute. And by compelling, I mean a literal compulsion: it is part of our constitution that we coo over puppies, that we soften at the sight of a big-headed, small-limbed mutt, that we go ga-ga for a pug nose and a furry tail. It has been suggested that humans are adapted to be attracted to creatures with exaggerated features—the prime examples of which are human infants. Infants come with comically distorted versions of adult parts: enormous heads; pudgy, foreshortened limbs; teeny fingers and toes. We presumably evolved to feel an instinctual interest in, and drive to help, infants: without an older human’s assistance, no infant would survive on its own. They are adorably helpless. Thus those non-human animals with neotenized (infantlike) features may prompt our attention and care because these are features of human juveniles. Dogs accidentally fit the bill. Their cuteness is half fur and half neoteny, which they have in spades: heads overly large for their bodies; ears all out of proportion with the size of the heads they are attached to; full, saucer eyes; noses undersized or oversized, never nose-sized."

It's not just their appearance, their juvenile play behaviors also remind us of children and coax us into a caregiver role.   Our empathy is also triggered by perceived helplessness; a study showed that people were more empathetic towards puppies, children and full grown dogs than for human adults and women were significantly more empathetic than men.  A study showed that 81% of Americans consider their dogs to be equal members of the family, while 58% are comfortable calling themselves their pet's Mommy or Daddy.  Another study showed that 65% of dog owners admit to taking more photos of their dog than their signicant other; another poll showed that pet owners had more pictures of their pet on their phone than their kids.