Source: Photo by Mary Jean Herzog
According to a 2021 survey by the Human-Animal Bond Research Institute, 87% of pet owners have experienced improvements in their mental health due to having a companion animal. I have certainly felt that way about the impact of pets on my life.
Unfortunately, however, most high-quality studies have found that, after socioeconomic and demographic factors are taken into account, pet owners are not less depressed, less lonely, happier, or healthier than people without pets. This mismatch between our personal experience with the benefits of pet ownership and “the science” is called “the pet effect paradox.” It is, arguably, the biggest mystery in anthrozoology—the study of human-animal relationships. Two large studies now suggest this pet effect paradox also applies to the positive influence of pets on child development.
The Pet Effect Paradox and Child Development
Fueled by headlines like 8 Ways Kids Benefit from Having a Dog, the claim that science has demonstrated that pets are good for kids is now widely accepted. But is it true? In a 2017 article, Rebecca Purewal and her colleagues reviewed several dozen studies on the impact of pets on the behavior, cognitive skills, and social development of children and teenagers. Some studies did report that kids with pets were psychologically better off than children without pets. The results of the studies, however, were mixed and many of them had a fatal flaw—the researchers did not take “confounding variables” into account. These are non-pet related factors that could affect well-being, such as differences in family wealth, parental education, and housing.
A New and Very Large Study of Pets and Child Development
Recently, a high-powered team of researchers led by Carri Westgarth at the University of Liverpool conducted the most extensive study to date on the effect of pets on the development of children and teens. The subjects were 14,000 children and adolescents in the Children of the 90s Study, an epidemiological study established in 1991 in England to examine factors related to children’s health and development.
In addition to the large number of participants, the research project was unique in several ways.
- It was a longitudinal study—the same kids were assessed multiple times between the ages of 2 and 15.
- The researchers reported the results of over 200 separate statistical analyses related to aspects of the emotional, behavioral, social, cognitive, and educational status of participants who had a pet and children who did not.
- The researchers considered how different types of pets affected child development (owning a dog, a cat, “another type of pet,” and “any pet”).
- The researchers controlled for dozens of potential confounding variables, aside from pet ownership, that could influence the children’s developmental outcomes. These ranged from differences in ethnicity and family income to maternal depression.
Westgarth and her colleagues hypothesized that kids with pets (and particularly dogs and cats) would:
- score higher on measures of self-esteem, language development, and educational attainment
- score lower on measures of anxiety, depression, and behavioral problems
The Surprising Results
The results of the study were recently published in the journal BMC Pediatrics. After controlling for confounding variables, the researchers found only a few positive outcomes out of several hundred analyses related to pet ownership and child development. In some areas, kids with pets were significantly worse off than their no-pet peers. Here is an overview of the results.
- Emotional Health – The researchers found no evidence that having a pet was related to any of a slew of emotional health outcomes. Indeed, they concluded, “Our findings are at odds with the common belief that companion animals benefit the emotional health of children and young people.”
- Behavioral Problems – Pet-owning and non-owning kids did not differ in most of the behavioral analyses. The good news was that children with pets were better off in a few behavioral areas. For example, three-year-olds who had dogs or “miscellaneous pets” had higher pro-social behavior scores. But in 6 areas of behavioral development, pet-owning kids exhibited more problems.
- Cognitive Development – With one exception, there were no differences in cognitive development in kids with and without pets. (The exception was that eleven-year-olds with dogs had more difficulty rapidly shifting their attention between tasks.)
- Language Development—Five-year-olds with “any kind of pet” had slightly better language comprehension scores than five-year-olds who did not have a pet. And two-year-olds with a pet had higher non-verbal communication scores. For other language variables, however, having a pet made no difference.
- Educational Attainment—The biggest surprises were related to educational success. When assessed at ages 7, 11, and 15, children with pets scored lower than kids without pets on about half of the educational success variables. For example, 7-year-olds with pets had lower scores on reading, writing, and math. While the differences tended to be small, teens with a pet were less likely to get good grades in biology, chemistry, and English. It is important to note that these differences do not imply that have a pet causes lower academic achievement. Westgarth and her colleagues suggest that an unknown confounding factor might explain the academic performance difference among pet-owning children. Perhaps, for example, some parents may get a dog to help support children who are having difficulties in school.
Does the Pet Effect Paradox Apply to Child Development?
This research is important. It is the first study to examine the impact of pets on the development of language and on educational achievement in children. And, more than any previous research on pets and children, the investigators controlled for a host of socio-economic and demographic factors.
The surprise was that, except for a few differences in the areas of social behavior and language, there was little evidence that children with pets were developmentally better off than kids who did not have a companion animal. The results of this study are generally consistent with the findings of a 2017 study of 5,200 children by the Rand Corporation. The investigators in that study concluded “differences between pet-owning and non-owning kids disappeared when factors such as race, homeownership, parental health, and wealth were taken into account.”
Pets played a vital role in my childhood and the same is true for my children when they were growing up. I simply can’t reconcile the conflict between the results of these large well-designed studies and our personal experiences with pets. In short, the pet effect paradox—the mismatch between our personal experience and the results of empirical research—may apply to child development as well as studies on the impact of pets on human mental and physical health.
In an email to me, Carri Westgarth wrote. “My personal takeaway is that, similar to the body of literature in adults, pets can support and encourage social interactions with others, but are not a panacea for treating our low moods or anxieties about life. What this data can’t tell us is how owning a pet may still help comfort children whilst dealing with life’s challenges.
I agree.
(You can read the full text of Westgarth’s team’s paper here.)
