Layla Parast, a study co-author: “We could not find evidence that children from families with dogs or cats are better off either in terms of their mental wellbeing or their physical health.”

If your parents never let you have a dog or cat when you were a child, don’t feel deprived. Children who grow up with such animals in their homes are not more likely to have better mental or physical health than their petless peers, according to a study published this week in the journal Anthrozoos.

That finding goes against the widely held belief — expressed both in academic journals and in the popular press — that pets are beneficial to children’s emotional and physical development.

Some animal lovers may not like the new study’s results, but they’re going to find it difficult to dismiss them. Conducted by researchers at the nonprofit RAND Corporation, the study offers the most comprehensive and rigorous look at this topic to date. For, unlike earlier studies, it used advanced methods of statistical analysis to control for a variety of confounding factors other than pet ownership — like family wealth — that are known to be associated with healthier children.

“We could not find evidence that children from families with dogs or cats are better off either in terms of their mental wellbeing or their physical health,” said Layla Parast, a study co-author and a statistician at RAND, in a released statement. 

“Everyone on the research team was surprised — we all have or grew up with dogs and cats,” she added. “We had essentially assumed from our own personal experiences that there was a connection.”

Study details

For the study, Parast and her colleagues analyzed data collected from about 5,200 households with children who participated in the 2003 California Health Interview Survey, the only year that the annual survey has asked participants about whether they had pets. More than 2,200 of those households reported having a dog or a cat (or both) in the house.

The researchers then compared the mental and physical health of the children (as reported by their parents or guardians) in the pet-owning homes with those in the petless ones.

The analysis revealed what earlier studies had reported — that the children living with dogs and cats tended to have better general health. Their parents were also less likely to report that they were concerned about their children’s mood, behavior or ability to learn (although children who had pets were more likely to have attention deficit hyperactivity disorder, or ADHD).

But the positive benefits from pet ownership disappeared after the researchers used some sophisticated statistical tools to account for more than 100 factors known to be associated with children’s health, including family income and the type of housing and neighborhood in which the children live.

After controlling for those factors, “we found that the estimates of the effect of pet ownership were dramatically reduced and that there was no longer any evidence of significant effects of pet ownership,” Parast and her colleagues write.

Limitations and implications

This study may be the most rigorous one to date to investigate the relationship between pets and children’s health, but it has its own set of limitations. As its authors point out, although the households in the study were racially and ethnically diverse, they came from a single geographic location — California. The findings might differ if a similar analysis were to be done with data from other states (or countries). Also, the study did not assess whether the length of time a pet lives with a child or the quality of the child’s interaction with the pet has an impact on the child’s health.

Still, Parast and her colleagues say their study suggests — contrary to popular opinion — that at least “some of the previous evidence of positive benefits of pets may be attributable to confounding.”

We will probably never come to a consensus about this issue, however, for, as Parast points out in the press release, the only way to truly test it would be a randomized trial in which some households with children are given pets and others are not — and then the families are followed for 10 or 15 years.

“Such a study would likely be too costly and/of infeasible to implement, and I’m afraid it’s not likely to be funded by anybody,” she said. 

FMI: You’ll find an abstract of the study on the Anthrozoos website, but the full study is, unfortunately, behind a paywall.

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4 Comments

  1. Underlying assumptions are always questionable in large statistical studies and especially so when a former powerhouse like RAND is trying to become relevant again.

    Physical health benefits of pet ownership have been shown as similar to that of rural contact with livestock, or if you like, a return to nature from a sterile life dictated by the old germ theory of disease.

    Mental health is far more complicated and subjective to the reality one imposes on their investigative framework to look at it. The investigators are right to point out that results from several thousand Californians are very questionable, but without being able to look at the study in the light of all of the life sciences, but the real question here is who pays for a RAND study and why.

  2. Underlying assumptions are always questionable in large statistical studies and especially so when a former powerhouse like RAND is trying to become relevant again.

    Physical health benefits of pet ownership have been shown as similar to that of rural contact with livestock, or if you like, a return to nature from a sterile life dictated by the old germ theory of disease.

    Mental health is far more complicated and subjective to the reality one imposes on their investigative framework to look at it. The investigators are right to point out that results from several thousand Californians are very questionable, but without being able to look at the study in the light of all of the life sciences, the real question here is who pays for a RAND study and why.

  3. Funding sources

    The only funder listed is the National Institutes of Health Eunice Shriver National Institute of Child Health and Development.

  4. Funding aside and

    Funding and the usual Disraeli statistics consideration aside, the largest confounding variable in this and every other broad health question today studied is our epidemic of non-communicable disease (read the Human Superorganism by Rodney Dietert); a pet can only do so much for us when the more sinister elements of our culture are doing us in.

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