It is often reported that pets are beneficial to human health. However, one researcher argues there is not yet enough evidence to conclude that pet ownership offers a generalized benefit to human mental and physical health.
Dr. Harold Herzog is a professor of psychology at Western Carolina University. He has been studying human-animal interactions for over thirty years. Herzog examined the body of research relating to the psychological and health benefits of pet ownership while he was writing his book “Some We Love, Some We Hate, Some We Eat: Why It’s So Hard to Think Straight About Animals.”
HH: “I began to gather all the articles that I could find that had been published on the topic from a scientific perspective and the thing that surprised me was that I did have a pretty big stack of papers showing that pets were, in fact, good for people, that they improved various aspects of human health and psychological well-being or happiness. But the thing that surprised me was the number of papers that I found in which researchers found no effect of pets on happiness or, in some cases, that pet owners were worse off. And I began collecting these piles of research and the thing that was interesting was how big all three piles were.”
KI: So owning a pet doesn’t provide an across the board benefit all groups of people?
HH: “That’s true of most medical treatments. For example, not everybody benefits from anti-depressant drugs. Some people do and some people don’t. On the whole, the effect of antidepressant drugs is smaller than most people think. And I think the same is probably true with pets. And just like with antidepressant drugs, there are downsides of pet-keeping. For example, in the United States, 85,000 people a year are taken to hospitals because they trip over their pet. I happen to know three of them. Pets are the second largest source of conflict between neighbors. There’s no evidence that, as a group, pet owners live longer than non-pet owners. But I’m not arguing that on the whole, pets are bad for people. But I think the evidence that they’re on the whole good for people is really mixed.”
KI: What do you think is causing this disparity of findings?
HH: “There’s a number of reasons that I think the research in this area is problematic. And one is a lot of it is based on self-report. I’m a pet owner. I’m a pet lover. I really like to believe and indeed I think that my pet makes me happier. She’s a cat, she sits on my lap in the evening, I’m watching television or reading a book. I feel that I feel better. But that’s not the same thing as objective evidence on that.
For example, one of the best studies in this area was done in Northern Ireland by Debbie Wells. She looked at people that were suffering from chronic fatigue syndrome. Half of the people that she looked at had gotten pets. Half of them had not. She went back, six months after people got these pets, and she asked them, ‘Does your pet make you feel better?’ and almost all of them said, ‘Yes.’ But then, she had actually given them some objective measures of their symptoms with chronic fatigue, before they got the pet and six months later, and found that there was absolutely no difference. So the people thought that their pets were making them feel better, but in reality, when you looked at the severity of their symptoms, there was no difference at all.
KI: What about claims that pet owners are less lonely than people who do not own pets?
HH: “Well, in fact, some studies have found that pet owners are more lonely. That’s the other thing is that one of the stacks of papers on the floor of my office when I was accumulating this data, was the stack of papers that found that pet owners were worse off. Some studies have found, for example, that pet owners are more likely to be depressed, more likely to have panic attacks. They’re more likely to smoke, they’re more likely to be obese. They’re more likely to have ulcers, they’re more likely to have migraine headaches and the list sort of goes on from that. It’s not all a bed of roses when it comes to living with animals.”
KI: Pet owners are a self-selected group. How does this effect the research?
HH: “We have very, very few what are called random clinical trials, which would be analogous to a drug study, where half the people get antidepressants, half the people don’t, and you follow their progress. Most of the studies that we do have compare pet owners with non-pet owners. And let’s say, for example, that you find that pet owners get more exercise. Well, it’s possible that it’s not the pet owning that made them get the exercise, but the fact that they had more energy to begin with and that’s why they decided to get a pet. So we have a problem when it comes to figuring out what’s causal and what’s not causal in terms of doing research in this area.”
KI: Why do people seem to generally believe that owning pets benefits their health?
HH: “I think the idea really started getting national news back in 1980, when a woman named Erika Friedmann, who is a very good researcher, was working on her doctoral dissertation at the University of Pennsylvania. Her doctoral dissertation was on the effect of social connections on survivorship from heart attacks. And she was following a group of roughly one hundred heart attack over the course of a year. A bunch of them died. As sort of an afterthought amongst the questions that she asked when she originally recruited the people was ‘Do they own a pet?’ What she found out after the year, and she actually had the mortality rates, was that the pet owners had roughly one-fourth the number of deaths over the course of the year as the non-pet owners.
This was what I think really started the idea that pets were good for people. The thing is there have been a number of studies since then that have shown this effect. They’re the ones that get all the press. Interest groups like the American Veterinary Medical Association, the Pet Products Manufacturers Association, people that sell dog foods and leashes and things like that, they really push this idea that pets are beneficial to human health. Again, my argument is that the results are actually mixed when you look at the totality of studies.”
You can find more information on the studies discussed and others at Herzog's blog on Psychology Today, "Animals and Us."
Katya Ivanov, WUWF News