Why Do Most Cats Sleep on Their Left Side?

"Cats sleep a lot. According to modest estimates, between 12 and 16 hours a day, that's most of what they do. Probably every cat owner knows this. However, a new study, published in the journal Current Biology, reveals something cat owners may not notice: cats tend to sleep on their left side. Two-thirds of the 408 observed cats slept on their left side and only one-third on their right side, a statistically significant difference."

"The data the researchers used was a set of YouTube videos of cats sleeping. This is a surprisingly simple and efficient way of gathering data, and also points to an important advantage researchers of cat cognition have in comparison with, say, researchers of primate or corvid cognition, namely, that cat owners are very enthusiastic about their pets and this can lead to some non-traditional research methods in the study of the feline mind."

"In some ways, it has to do with what I started this post with: the extreme time cats spend sleeping. More time spent asleep means more time when the animal is the most vulnerable. As a result, cats try to fall asleep in a way that minimizes the possibility of being attacked when they can't defend themselves. This may also be the reason for another, less scientifically documented, but anecdotally plausible, aspect of cats' sleeping behavior. Namely, that they often prefer sleeping on some kind of elevated platform."

Domestic cats typically sleep 12–16 hours per day. Observations of 408 sleeping cats showed a significant left-side sleeping preference: about two-thirds left, one-third right. Data were drawn from YouTube videos of sleeping cats, using owner-submitted footage to gather occurrences. A conjecture links the left-side bias to long sleep duration: increased time asleep raises vulnerability, so cats adopt positions that minimize attack risk. Preference for elevated sleeping surfaces is noted as another vulnerability-reducing behavior. The precise mechanism behind the left-side preference remains a conjecture and is not definitively established.

Read at Psychology Today