Jon Stweart

The truth about cats: Left paw = right-brain male / Right paw = left-brain female.

The late-night comedian and Daily Show host Jon Stewart used to a bit called, “According to a new study…” as a way to draw attention to TV newscasts that over-rely on studies to provide news content and fill air time.

The media world — and the animal kingdom in general — 

has been tossed upside down in the past week by a new study that claims cats are right-pawed or left-pawed, depending on which front paw they use first to reach out or swat something with.

According to this study, published in the January issue of the journal Animal Behaviour (Est. 1953), right-handedness and left-handedness in cats is determined by gender: Male cats tend to favour their left paw; females tend to favour their right.



One can be forgiven for taking the study with a grain of salt, or catnip if you prefer, because we’re living in the era of Fake News, aka #fakenews — and because, as Stewart reminded us on an almost nightly basis on his Daily Show,  the media like nothing more than a new study that tells us something we didn’t know, and has broad audience appeal besides.

This particular study, as reported by National Public Radio (NPR) in the United States, and many, many other media outlets, including Smithsonian magazine, The Guardian and, to name just a few, was conducted by a trio of psychology-department researchers at the Animal Behaviour Centre at Queen’s University in Belfast, Northern Ireland.

The study involved 44 cats in all — 24 male, 20 female, all neutered or spayed, of mixed breeds, between the ages of one and 17 years.

Cat owners were asked to monitor their cats’ daily routine, focusing on spontaneous behaviour such as what paw they used to reach for food, step into their litter tray, or climb up and down a flight of stairs. Cat owners were also asked to monitor whether their cat preferred to rest or sleep on which side. Survey participants — the humans, not the cats — were asked to monitor their cat’s behaviour every day until 50 responses were reached for each question.



The study is not entirely new. Behavioural psychologists at the same university conducted a similar study in 2010, as reported at the time in Pets Magazine and other places.

That study found that, as with human left- or right-handedness, cats do tend to favour one paw over the other. The results then were similar to the results now. The 2010 researchers found that most cats will use either paw for simple things. When faced with a more complex task that requires dexterity, female cats will favour their right paw while male cats will favour their left.

Fake news? Or yet another case of cats being, well, cats? It could well take a cat psychologist to suss out the difference. 

In the 2010 study, as reported at the time in the Daily Telegraph, “in one particularly difficult task – fishing a piece of tuna out of a small jar – all 21 females used their right paw.”

Twenty of the 21 tom cats studied used their left, while one of the males was judged to be ambidextrous.

In simpler games, such as grabbing a toy mouse and dragging it along on a string, cats showed equal preference for either paw.



The researchers likened the pattern to the way we humans use either hand for a simple task, such as opening a door, but favour one hand over the other for writing.

“The more complex and challenging (the task), the more likely we’re going to see true handedness,” study leader Dr Deborah Wells told New Scientist magazine at the time.

Though the idea of testing right-handedness against left in house-cats sounds like the classic definition — where there is any definition at all — of fake news, there is a scientific question that goes beyond finicky couch moggies.

Studies of chimpanzees in the wild have shown that individual chimpanzees show a distinct preference for one hand over the other when using tools.

Hand-preference in primates is complicated, and not always easy to judge. There are still a lot of unanswered questions. Among humans, for example, left-handedness is more common among men than women, but no one can explain why.

©Queen's University Belfast/Dr. Deborah Wells

©Queen's University Belfast/Dr. Deborah Wells

“Further work is needed to investigate this,” study co-author Wells told NPR earlier this week. “The strong (gender) effects reported here . . . point more and more strongly to underlying differences in the neural architecture of male and female animals.”

Aside from the curiosity factor, why does any of this matter?

Left-limbed animals, Wells told NPR, rely more heavily on the right hemisphere of their brains, and tend to display more aggression and a more pronounced reaction to fear than right-limbed animals, which tend to use the left hemisphere of their brains more.

I can personally attest to one of the results of the study: My own couch moggy, a female, favours her right paw over her left — and I have the scars to prove it.