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Whether you think LOL stands for “laughs out loud” or (like British PM David Cameron) “lots of love,” it’s tempting to imagine that a bunch of scheming cats may have been behind the latest flurry of press attention over a study of cat welfare recently reported in the journal Physiology & Behavior. Or more seriously, it continues to amaze me how quickly research into the behaviour of companion animals comes to be misrepresented in the press.
First, the research. Scientists in São Paulo, Brazil, recruited cat owners to take part in a study examining links between the numbers of cats in a household, and a potential indicator of stress levels, the amount of a cortisol metabolite excreted in their faeces. They also asked the owners to fill out questionnaires that allowed them to offer their opinions as to the cats’ personalities, and how they behaved in a variety of situations, including the way they reacted to being stroked.
No straightforward relationship emerged between the number of cats in the household and the levels of the metabolite, but there was an enormous amount of variation between individuals. Some were excreting astonishingly high levels of the metabolite, equivalent to those produced (and only briefly) in “normal” cats by an injection of ACTH, the hormone that stimulates the release of cortisol. Whether these high levels are really indicative of psychological distress in companion animals, or some other disturbance of metabolism, is still unclear: some dogs in rehoming centres also excrete extraordinarily high levels of cortisol without showing any consistent outward signs of suffering. The study revealed little about the reasons behind such unexpectedly extreme variation, apart from one: a difference between the 4 cats that were reported by their owners to “dislike” being petted and the 13 who “tolerated” being petted—and the statistics suggest that cats in the much larger group (85) whose owners thought they “enjoyed” being petted actually contained the biggest range of levels of excreted metabolites. However, it was the contrast between the “tolerate” (high levels of metabolite) and “dislike” group (low levels) that went into the Abstract—which, to be fair, is all that the non-technical press have access to if they choose not to pay to read the full journal paper. Hence (presumably) the following—
“Data showed that cats who tolerate being touched get the most stressed out about it, compared to the ones that enjoy or dislike it.” Actually there was little if any difference between the tolerators and the enjoyers.
“Animal behaviour experts stroked different cats to varying degrees. They tested the stress hormone levels of each cat before and after stroking” — not unless we classify all of São Paulo’s cat owners as animal behaviour experts, and also they don’t appear to have been instructed to vary the extent to which they stroked their cats, just report how their cats reacted on a typical day.
“A new study suggests that some cats don't like it when their owners pet them. In fact, it may actually stress them out.” This is almost certainly true, but the study doesn’t show this. It shows that a few cats that only “tolerate” petting also continuously excrete higher than average amounts of a cortisol metabolite—and all the time, not just after they’ve been stroked. Given that these cats only “tolerated” being petted, it’s highly unlikely that they received enough petting to account for their high levels of ‘stress’ (even assuming that is the correct interpretation for the large amounts of the metabolite): more likely, something else in their lifestyle was making them chronically stressed, and one knock-on effect is that they’re nervous about being touched.
And here’s an unhelpful suggestion from a news website: “So what's the logical solution if your cat hates you? Buy more cats! Or just replace the first one with a dog. Your call.” Getting more cats—or a dog that doesn’t understand cats—is likely to increase the stress levels among the existing cat(s) in a household. As the senior author on the paper, Professor Daniel Mills, says in the University of Lincoln’s press release “The results also reinforce the importance of ensuring that you give all individuals control over their environment, so if you have several cats you should give them the choice of sharing or having their own special areas to eat, drink and go to the toilet.”
The solution?—please, journalists, can you fact-check with the scientists before reporting their studies, so we don't have to set the record straight after the event? Cats will love you for it (if they’re not too busy thinking up captions for LOLHumans).
