Skip to main content

Verified by Psychology Today

Animal Behavior

Why Do People Think Animals Make Good Therapists?

New study helps explain why the "animal-assisted therapy" meme has gone viral.

In his groundbreaking new book The Animals Among Us: How Pets Make Us Human, pioneering anthrozoologist and Psychology Today blogger John Bradshaw writes: “I have found the most interesting feature of the ‘pets as panacea’ meme to be the enthusiasm with which the general public has accepted it."

Pet Memes?

Memes, of course, are Richard Dawkins’s hypothetical contagious elements of culture that spread from human mind to human mind via imitation and language. Memes include songs, ideas, and even baby names. And as my colleagues and I have shown (here and here), memes also play a role in our choices of pets

Graph by Hal Herzog
Source: Graph by Hal Herzog

The idea that animals make good therapists has the hallmark of a meme that has gone viral. As this graph shows, the annual number of research articles on animal-assisted therapy jumped from one in 1980 to more than 1,000 in 2015. A 2016 study in the journal Anthrozoos reported that 80 percent of parents in a community sample rated animal-assisted therapy as a high or very highly acceptable treatment for mental health problems in children.

The problem, however, is that there is a mismatch between what the public believes about the effectiveness of animal-assisted therapy and the actual scientific evidence that it works. For example, while you did not read about it in the newspaper, Virginia Commonwealth University researchers found that interacting with animals had no effect on pain or anxiety in hospitalized children, and investigators from the University of Toronto reported that therapeutic horseback riding was no more effective than learning to ski in reducing symptoms of people suffering from depression and anxiety. Furthermore, as I have described in a series of posts (here, here, and here), the validity of most studies on the curative powers of animals is compromised by methodological problems, such as small samples and lack of control groups.

The Availability Heuristic and Acceptance of Animal Therapies

Given the mixed results and sloppy science, why is the public so convinced of the powers of animals to heal human hearts and minds? One possibility is that human thinking is highly influenced by a mental shortcut that cognitive psychologists call “the availability heuristic.” This is the idea that our beliefs are particularly influenced by the information we are most commonly provided with. In the case of therapy animals, this would include encountering service dogs in hospitals and airports, or reading newspaper headlines such as “Adorable Service Dog Gave Suicidal Vet His Life Back.”

But some people are more susceptible to mental viruses than others, just as some will get the flu this winter, while their friends will not. Could this also be true of ideas that go viral — for example, the belief that dogs, horses, and dolphins make good therapists? And if so, what factors would predispose people to believe the “pets as panacea” meme? Molly Crossman and Alan Kazdin of Yale addressed this issue in a study recently published in the Journal of Clinical Psychology. Their results have important implications for researchers, therapists, and the public.

Specifically, they sought to answer two questions: First, do people generally perceive animal-assisted therapy to be superior to other alternative/complementary therapies such as music therapy and massage therapy? Second, do attitudes toward pet-keeping predispose people to accept the idea that animal-assisted therapy is a valid treatment for psychological disorders?

The Study

To answer these questions, Crossman and Kazdin recruited adults through Amazon’s online subject pool, MTurk. The 210 participants were equally divided between men and women with an average age of 34. Two-thirds currently owned a pet, and 91 percent had owned one in the past. Each participant read one of four slightly different fake news stories depicting research on the effectiveness of alternative therapies for the treatment of anxiety. The reports differed in the type of therapy (animal-assisted therapy, music therapy, or massage therapy) and the psychological problem (anxiety in college students or anxiety in patients undergoing MRI scans).

Here is a sample vignette:

"Animal-assisted therapy can reduce symptoms of anxiety among college students, according to a recent study published in the latest issue of the journal Mental Health. The researchers provided animal-assisted therapy to 35 students at a small liberal arts college in the Northeast. They found a 60 percent decrease in self-reported anxiety symptoms after animal-assisted therapy, delivered by a licensed professional. The authors note that the study had a small sample and did not include a control group. This means that future research is needed to confirm the benefits of animal-assisted therapy for college students. Still, this study suggests animal-assisted therapy could be an effective way for college counseling centers to meet the growing demands of their students. It is one of the first studies to apply animal-assisted therapy in a college setting and use a systematic form of measurement."

After they read one of the scenarios, the subjects completed a series of four questionnaires:

  • The Credibility/Expectancy Questionnaire, which measures attitudes toward different types of psychological interventions (“How much improvement in anxiety do you think typically occurs as a result of this treatment?”);
  • The Treatment Evaluation Inventory, which measures the perceived acceptability of therapies — that is, the degree to which people think an intervention is fair and reasonable and meets their expectations (“To what extent do you think there might be risks in undergoing this type of treatment?”);
  • The Semantic Differential, which measures the subjects’ evaluation of the treatment as good or bad; and
  • The Pet Attitude Scale, which measures the degree to which people feel positively or negatively about companion animals ("My pet means more to me than any of my friends.”).

The Results

Surprise: As a group, the participants did not rate animal-assisted therapy significantly better than the other forms of treatment for anxiety. Of the 210 subjects, there were no differences in how they evaluated the acceptability or effectiveness of animal, music, and massage therapy.

Graph by Hal Herzog/Photo by Susan Richey-Schmitz/123RF
Source: Graph by Hal Herzog/Photo by Susan Richey-Schmitz/123RF

But when Crossman and Kazdin compared the responses of the people with positive and negative attitudes toward pets, a much different pattern of results emerged. This finding is illustrated in this graph, which shows the average scores on the Credibility/Expectancy Questionnaire. As you can see, the subjects who liked pets were very enthusiastic about animal-assisted therapy after reading the fake news report. In contrast, subjects who had more negative attitudes toward pets were not particularly influenced by the animal therapy vignette. The measures of the acceptability of the therapies and the degree the subjects evaluated their therapies as "good" showed the same pattern.

Why Is This Study Important?

The results suggest that people with favorable attitudes towards pets are also more likely to be influenced by news reports touting the idea that animals make good therapists. These findings have important implications. First, they refute the idea that the spread of the “animals make therapists” meme is simply the result of media exposure (the availability heuristic). The reason is that subjects with positive attitudes toward companion animals were much more likely to accept information which depicted animal-assisted therapy as effective.

In addition, the findings have implications for animal therapy researchers. Over the last 30 years, I have met hundreds of human-animal interaction researchers, and nearly all (including me) are dedicated pet lovers. But wishful thinking about the healing powers of pets does not make for good science. As Alan Beck and Aaron Katcher wrote back in 1984, “Investigators studying the impact of pet-visitation or placement programs have a general tendency to suspend critical judgment of research findings to favor the belief that animals have therapeutic potential.” Their warning still rings true. Crossman and Kazdin correctly suggest that attachment to pets can be a liability when it comes to evaluating the effectiveness of animal therapies. They stress that researchers in this area need to be particularly vigilant to avoid unconscious bias in their studies involving therapy animals.

Finally, as the Yale researchers point out, psychologists have found that people with high expectations about the effectiveness of a particular therapy are more likely to get some benefit from the treatments. Does this mean people who are particularly pro-pet are better candidates for animal-assisted therapy? That may be the next step in this research collaboration. I’ve got my fingers crossed.

Facebook image: Look Studio/Shutterstock


Beck, A. M., & Katcher, A. H. (1984). A new look at pet-facilitated therapy. Journal of the American Veterinary Medical Association, 184(4), 414-421.

Crossman, M. K. & Kazdin, A. E. (2017) Perceptions of animal-assisted interventions: The influence of attitudes toward companion animals. Journal of Clinical Psychology, 2017;00:1–13.

Rabbitt, S. M., Kazdin, A. E., & Hong, J. E. (2014). Acceptability of animal-assisted therapy: Attitudes toward AAT, psychotherapy, and medication for the treatment of child disruptive behavioral problems. Anthrozoös, 27(3), 335-350.

More from Hal Herzog Ph.D.
More from Psychology Today