Large Study Finds Pet Owners Are Different

You’ve seen headlines like “Puppy Love: Pet Owners Are Happier, Healthier” and “How Pets Save Us Billions Every Year In Health Care Costs!” And it is true that a lot of studies have reported that pet owners have better physical and mental health than people who do not live with companion animals. But as I have pointed out in previous posts, the results of this body of research have been mixed (here and here). Further, we do not know whether getting a pet causes better health, or whether the causal arrow points in the other direction. In other words, pet owners might be different to begin with. If so, non-pet-related differences such as socioeconomic status might be the real cause of better health for companion animal owners. For example, people who are married, white, female, and wealthy have lower death rates. If individuals with these characteristics are also more likely to live with pets, we could wrongly conclude that it is dog or cat ownership that makes them live longer.

If we really want to understand the effects of companion animals on human health, we also need to know how pet owners and non-pet owners differ in terms of demographics. Investigators from the Rand Corporation and UCLA used a large data set to address this question. Recently published in the journal PLOS One, their research report offers important insights into the differences between pet owners and non-pet owners and the impact of pets on our health.

Big Data Shows Pet Owners Are Different

To study differences between pet owners and non-owners, the researchers turned to a huge data set – the ongoing California Health Interview Survey. Begun in 2001, it is the nation’s largest statewide comprehensive health survey. CHIS involves telephone interviews with randomly selected Californians. The interviews are conducted in five languages, and the sample is highly representative of the state’s population in terms of sex, race, household composition, and income. In addition to basic questions related to health and demography, the 42,044 adults interviewed in the 2003 CHIS survey were also asked about dog and cat ownership.

About half of the individuals interviewed lived with a pet: 26 percent of them owned a dog, 22 percent owned a cat, and 9 percent owned both. The researchers presented their results using statistics called “odds ratios.” Here is a summary of the results:

• Married people are more likely to have pets. The odds that a married person owned a dog were 34 percent higher than the odds for a non-married person, and 9 percent higher for owning a cat.
• Women are more likely to keep pets. The odds that a woman owned a dog were 8 percent higher than the odds a man owned a dog, and they were 16 percent higher for owning a cat.
• Large racial and ethnic differences exist in pet ownership. Whites were about 3 times more likely to own a dog and nearly 5 times more likely to own a cat when compared to non-whites. In contrast, black respondents were half as likely to own a dog and less than a third as likely to own a cat as other respondents. The pet ownership patterns of Hispanic and Asian respondents were similar to that of black respondents.
• Pet keeping is more common among homeowners. Homeowners were almost three times more likely to own a dog, and the odds that a homeowner had a cat were 60 percent higher than the odds for non-home owners.
• Wealthy people are more likely to live with pets than poor people. Individuals in higher income brackets were significantly more likely to own dogs and cats.

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So, according to this study, the answer to the question, “Are pet owners different?” is Yes, when it comes to demographics and lifestyle, but No, when it comes to health. Go figure.

(For a study by the RAND research group on why kids with pets are better off than children who don’t live with animals, see this post.)

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