Wednesday, February 3, 2016

Who loves you more: your dog or your cat?

Do cats really love us less than dogs do? I am not convinced. 

Recent reports in the media suggest that science has proved that dogs love humans more than cats do.

The finding comes from an experiment performed by neuroscientist Paul Zak by a BBC documentary, Cat v Dog. Zak is known for his research on oxytocin, what he calls the attachment neurochemical or “the moral molecule” because it motivates us to nurture offspring, and treat others with care and compassion.

When humans engage with each other socially, our bloodoxytocin levels may increase by 10 to 100 percent – with greater increase correlated with greater amounts of attachment or pleasure involved in the interaction. For example, our oxytocin levels may increase by 5-10 per cent when a new acquaintance shakes our hand, but they shoot up by up to 100 per cent if your own child hugs you.

According to reports, for this experiment Zak took saliva samples from 10 cats and 10 dogs at T=0 (ie before they interacted with their owners). They then engaged with their owners for a short period of time and he repeated the tests (T=1), in both cases measuring oxytocin.

After the experiment, dogs had an average increase in oxytocin of 57.2 per cent while for cats it was around 12 per cent – and some had no oxytocin at all.

What is fascinating is how this study – for which I cannot locate a peer-reviewed journal article – is being reported. In The Times of India, the headline reads “YourDog Loves You 5 Times More Than Your Cat: Study”.

Some reports, such as this one, suggest that the results are based on blood and not saliva tests. But the word "proof" is being thrown around as if the result of a single experiment is the definitive last word on a matter which may impact the way humans interact with animals and therefore impact their welfare. 

Before you give your cat the cold shoulder, remember there are limitations to every study. This one involved a small sample size, measured a single parameter, didn’t provide details about selection criteria (were there key differences in cats selected as opposed to dogs?) and didn’t measure cats in their own environment. 

As noted by Dr Zak, cats are territorial and may be secure in their own territory, but are often terrified when removed from their homes (the saying goes, “dogs love people, cats love places”) – which may have impacted the results. 

Methods can also impact results, particularly when different species are involved in a study. Measuring parameters in feline saliva is challenging for a number of reasons, not least of all because it can be difficult to collect an appropriate volume of saliva. False negative results may occur because of this methodology and there is still significant work to do to refine this modality.

On the other hand, blood tests (if they were performed) are stressful. In my experience, cats are generally more stressed than dogs about having blood drawn, although there is major individual variation (some cats don’t show any overt signs of stress, some dogs get very stressed). This might also impact results.

Is it fair to compare cats and dogs in a context that favours the dog in the first place? Is it fair to compare cats and dogs at all? What are we seeking to achieve here? And is the question who loves us best a tad anthropocentric? What does it say about us? As someone who works and lives with dogs and cats, reports about experiments like these don’t change the way I view my relationships with animals. And when it comes to cats, I think as a species we often read (and study) them wrong.

How did you react to the findings?