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Are Pets as Good for Us as We Think They Are?

What does the science really say about the impact of pets on human health?

Key points

  • The "pet effect" is the idea that getting a companion animal will improve physical and mental health.
  • Like a growing number of studies, a large study from Tufts University found that pet owners were not better off than non-pet owners.
  • The reasons for the mismatch between what we believe about the positive impact of pets on our lives and actual research results are unclear.

Megan Mueller, co-director of the Tufts University Institute for Human-Animal Interaction, is a leading researcher on the impact of pets on human health and well-being. She was initially drawn to this area of study in graduate school when she adopted a black Lab mix named Jett. In an e-mail, she told me, "I definitely believe he enriches my life in many ways. My relationship with him certainly influenced my decision to pursue this area of research."

Photo by Hal Herzog
Katie and Moose
Source: Photo by Hal Herzog

The pet products industry refers to the impact of companion animals on human physical and mental health as “the pet effect.” My daughter Katie and her wife Janna are certainly believers. Moose, their two-year-old golden-doodle has changed their lives. When I asked Katie what she gets out of her relationship with Moose, she said, “Love. His affection is endless. He brings excitement and enthusiasm into our home. He is always so excited to see me—even if I have just gone outside to get the mail. We take him everywhere—camping, hiking, canoeing. Our desire to give him a good life gives us a good life. And Moose makes me less lonely. He is my best friend.” Janna, a nurse who works with COVID patients, added that Moose gives her something to look forward to after her grueling shifts in the hospital. “He gives me hope,” she tells me.

Industry trade groups like the Human-Animal Bond Research Institute (HABRI) claim that the latest scientific research of the pet effect overwhelmingly supports the idea that getting a companion animal will decrease your blood pressure and stress levels, reduce anxiety and depression, improve your cardiovascular health, and even make you live longer. For example, HABRI’s president, Steve Feldman, writes that science has shown that pet ownership is “an essential element of human wellness, for quality of life, physical and mental health.”

It is true that some studies have shown that pet owners are better off. However, an increasing number of research reports cast doubt on the pet industry claims getting a pet is a key to health and happiness. Take, for example, a recent study by Megan Mueller and her research team at Tufts University.

What Research on the “Pet Effect” Really Says

The investigators were interested in two questions:

  1. What type of people own pets?
  2. Is living with a pet associated with better physical and mental health?

What makes this study special is that the results were based on a large representative sample of American adults. The 1,267 participants were obtained as part of a Tufts University interdisciplinary study on aspects of health, wealth, and equity in Americans. The subjects were asked a series of demographic questions related to, for example, gender, education, marital status, and income. The items related to health include measures of general physical health, body mass index, exercise, physical disability status, cognitive problems, and the presence of anxiety disorders and depression. The participants were also asked if they owned a pet and what kind.

The Surprising Results

The study’s findings on the demography of pet ownership were interesting. For example, pet ownership was not related to household income, individuals with college degrees were less likely to own pets than individuals with high school degrees, and people with kids at home had higher rates of dog ownership but not higher rates of cats ownership.

The most important results, however, were related to the effects of living with pets on health and well-being. After statistically adjusting for demographic and socio-economic differences, there was no evidence that pet owners were physically or psychologically better off than people who did not have a companion animal in their lives.

  • Neither dog nor cat ownership was associated with the participants’ general health status.
  • While dog ownership (but not cat ownership) was associated with higher levels of physical activity, this did not translate into differences in the Body Mass Index of pet owners and non-owners.
  • The bad news is that cat owners were twice as likely as non-pet owners to suffer from cognitive problems related to learning, remembering, or concentrating.
  • Female pet owners were more likely than non-owners to have anxiety disorders. However, male pet owners were less likely than non-owners to suffer from anxiety.
  • Depression was twice as common in pet owners as non-owners. This was true of both dog owners and cat owners.

Dr. Mueller and her colleagues were surprised that pet ownership was not linked to better health. However, their results were not an anomaly. In the last few months, for example, this study found that a stuffed toy dog was as effective as a real dog in reducing anxiety in adults awaiting outpatient surgery. This study reported that having a pet did not alleviate loneliness in teens during COVID. And this study found that interacting with a dog had no impact on anxiety or cognitive performance in lab situations. Further, only 5 of 30 studies on the impact of pets on depression found that pet owners were less depressed (here). And most studies have found that pet owners are just as lonely as non-owners (here)

The Pet Effect Paradox: What Owners “Know” vs. What Science Says

The authors of a recent review of pet effect research in the journal Applied Developmental Science wrote, “The mass media and the public seem to have an inexhaustible appetite for stories of animals helping people with their illnesses and disabilities. Unfortunately, satisfying this appetite often results in superficial and inaccurate media accounts of scientific findings.”

Most pet owners—including me—personally believe that our pets make our lives better. But what we want to believe about pets does not always jibe with the results of empirical research. I call this the “pet effect paradox.” It is exemplified by a study at Queens University of pet owners who suffered from chronic fatigue syndrome. All of the subjects were convinced that their pets provided them with a wide range of medical and psychological benefits. Yet objective measures of their symptoms showed they were just as tired, stressed, and depressed as CFS patients who did not have pets.

For Tuft’s Megan Mueller, the pet effect paradox is personal. She decided to focus her research on the human-animal bond, in part, because she experienced the benefits of living with her dog Jett. Yet some of her own studies have not supported the “pet effect” idea. She told me the mismatch between pet owners’ perceptions of the benefits of living with animals and the results of recent research on the topic is something she thinks about all the time. And she added, "What if it is the case that we perceive our pets to be beneficial for us, but we can’t find any measurable effects? Practically, does that matter, or not?"


    For more on the "pet effect," see:

    More about Katie Herzog's moral quandary over whether to have her dog Moose desexed:

    Facebook image: Lopolo/Shutterstock

    LinkedIn image: PUWADON SANG/Shutterstock


    Mueller, M. K., King, E. K., Callina, K., Dowling-Guyer, S., & McCobb, E. (2021). Demographic and contextual factors as moderators of the relationship between pet ownership and health. Health Psychology and Behavioral Medicine, 9(1), 701-723.

    Serpell, J., McCune, S., Gee, N., & Griffin, J. A. (2017). Current challenges to research on animal-assisted interventions. Applied Developmental Science, 21(3), 223-233.

    Wells, D. L. (2009). Associations between pet ownership and self-reported health status in people suffering from chronic fatigue syndrome. The Journal of Alternative and Complementary Medicine, 15(4), 407-413.

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