Our complicated relationship with cats

Cats are brilliant creatures, and there's more psychological research on felines and their owners than you might think

A wealth of research shows that our interactions with cats affect us in a surprising number of ways. Photograph: Frances Etchells

It would seem that I've made an unforgivable error. Last week, I wrote about a new study that suggested a possible function for sleep. The research in question was a mouse study, so it seemed to make sense to stick up a picture of a mouse alongside the article. However, lots of commenters were outraged – OUTRAGED – that there wasn't a picture of a sleeping kitten instead. So to make amends for my transgression, today I'm going to look at some of the psychological research that's been conducted on cats and their owners. Don't say I don't do anything for you.

The psychology of cat people

Do you identify as a dog person, or a cat person? A study in 2010 asked 4,500 people to self-identify as either a dog person, cat person, both or neither, and looked at five personality traits using a self-report questionnaire. People who identified themselves as cat people showed significantly higher scores for neuroticism and openness than dog people, and significantly lower scores for extroversion, agreeablenessand conscientiousness. In other words, we (I'm a cat person) tend to stress more, be more open to a variety of experiences, but show poorer self-discipline, cooperativeness and assertiveness.

And according to another survey from 2010, people who are more highly educated were 1.4 times more likely to own a cat than a dog. This doesn't mean that cat people are smarter than dog people, more that there's a link between higher education and longer work hours. Cats are less time-consuming than dogs, and so people who work longer hours will be more likely to choose cats as pets to fit in with their work life.

The psychology of … cats?

So much for cat people, but what about cats themselves? A study published in Psychological Reports in 2008 asked cat owners to rate their pets across 12 different personality aspects, including curiosity, friendliness, aggression and bad temper. The researchers used a method called principle components analysis to figure out whether there were any general underlying cat personality variables, and found four. The first incorporated traits such as activeness, intelligence, curiousness and sociability. The second seemed to be driven by how emotional, friendly and protective the cats were. Component three consisted of aggression and bad-temperedness, and component four was moderated by timidness. So it would seem that cats can have different personalities too – at least, based on the reports of their owners.

Or maybe it's just down to emotional bonds being established between owners and their pets. The stereotypical cat is often seen as a highly aloof animal which isn't particularly interested in human contact. But a 2007 study by Claudia Edwards and colleagues in the Journal of Veterinary Behaviour looked at attachment in cats, and found behaviour consistent with that which you would see in young children.

Attachment theory was developed in the late 1950s as way of characterising affectionate bonds between two individuals, one of which is usually a caregiver. The creation of such a bond between a parent and child, for instance, makes it more likely that the child's basic needs are met, and the child tends to relax around the caregiver. On the other hand, if the child is placed in the company of a stranger, they might become more anxious, upset with their caregiver, or distressed in some way. Similarly, Edwards' study found that when cats were in the company of their owners, they tended to show more relaxed attachment behaviours such as wandering around, exploring and playing in their environment. When they were placed with a stranger instead, the cats meowed less, and spent more time waiting by the door.

So maybe cats aren't as aloof as we first thought.

Cats and health

It's often suggested that having a pet can improve your mood, howeverresearch from 2003 suggests that the relationship is a bit more complicated than that. Dennis Turner and colleagues looked at how the presence of cats in the home affected positive and negative moods, and how this compared to the presence of a partner. They found that having a cat only appeared to affect negative moods – i.e. people were less likely to feel bad if they had a cat, but not necessarily feel more positive or happy. It was only the presence of a partner that appeared to enhance positive moods.

A more controversial issue around whether cats affect our mood centres on a parasite called Toxoplasma gondii. T. gondii is one of the most common parasites to infect humans, with some studies suggesting that up to a third of the entire human population may be infected with it. The usual transmission vector is through exposure to cat feces, and while for the most part T. gondii is pretty much symptom-free, there seems to be growing evidence that it may be implicated in certain diseases and disorders such as schizophrenia and depression. For example, studies on people who are diagnosed with schizophrenia have been shown to have a higher number of T. gondii antibodies in their system than do controls, suggesting that the parasite has been in their systems at some point.

T. gondii has also been linked to general changes in personality, although this connection is a bit more tenuous, based on correlations and small sample sizes that haven't yet been replicated by other labs.

That being said, the answer is probably not to get rid of your cat. While cats are an important part of the sexual cycle of T. gondii, research suggests that owning one doesn't impact on your risk of getting infected. There's evidence that owning a cat can be good for you in other ways too, such as reducing the risk of death from stroke and heart attack. And besides, without cats, this would never have happened.