A purrfectly reasonable explanation
Let’s take a look at the most wonderful of sounds to a cat-owner – a purr. Why do cats purr? How do they purr? What’s the purrrpose of it all? (sorry)
Why do cats purr?
It's easy to assume that cats purr because they're happy. All contented kitty owners have experienced that moment of satisfaction when your cat happily curls into a ball in your lap for some strokes and the purr-motor revs into over-drive. That is obviously one happy feline – and one happy owner too no doubt!
However, cats also purr when they’re frightened or feel threatened, such as during a visit to the vet, or after a scuffle with another cat. If you apply this to human behaviour it is easy to make a comparison – people smile when they are happy, for sure, but we also smile when we are nervous, when we want something, or when we are trying to disguise emotions.
Here are some reasons your cat might purr:
Some cats purr when it's mealtime. British researchers studied the sounds that house cats make when they're hungry and when they’re not. Interestingly, the purrs don't sound the same but it is a purr nonetheless!
Many cats purr when they are in pain or are hurt. It might be a way for a cat to soothe itself, like a child sucking their thumb, but some research suggests that purring actually aids cats’ recovery. The low frequency of purrs causes a series of related vibrations within their body that can heal bones and wounds and build and repair tendons. It also eases their breathing and lessens pain and swelling. This might explain cats’ nine lives reputation, and perhaps why cats can survive falls and tend to have fewer complications after surgeries than dogs.
Your cat may also purr to communicate with you. According to research, domestic cats can hide a cry within their purrs that irritates their humans while appealing to their nurturing instincts. It works on a similar frequency to the cry of a human baby – ensuring our attention, and appealing to our nurturing sides. Clever kitties!
Kittens develop the ability to purr when they are only a few days old. It is thought likely that it is a way to let their mothers know that they are ok. The mother cat may use her purr as an audible comfort when the kittens are too little to see well and don’t respond much to other stimuli.
How does a cat purr?
A purr begins in the brain. The cats’ laryngeal muscles receive a message from the neural oscillator, causing the muscles in the throat to twitch very fast – at a rate of 25 to 150 vibrations per second. This causes the vocal cords to separate when the cat breathes in and out and produces a purr.
Do all cats purr?
Not all cats can purr. Domestic cats, some wild cats purr, and some relatives of cats like civets, genets and mongeese purr - and their relatives purr too. Further afield, hyenas, raccoons and guinea pigs, gorillas, raccoons, rabbits, ring tailed lemurs, tapirs, and elephants are examples of other animals who can also purr.
Cats that purr cannot roar, and cats that roar cannot purr: the structures surrounding roaring cats’ larynxes aren’t stiff enough to allow purring. The roaring cats evolved this way because these cats move around a lot to catch prey, so they developed their roar to protect their prides and territory. Purring cats, on the other hand, are smaller and use scent to mark territory. They are more likely to be solitary animals that don’t have to compete with each other for prey.
Is purring beneficial for humans too?
Purring is also healthy for cat owners. Studies show that cats are better at lowering blood pressure and relieving stress than other pets. Studies show that cat owners were 40 percent less likely to have heart attacks than non-cat owners — and purring might play a role in that.
Purring is undoubtedly a sound that people associate with peacefulness and calmness which may help to create contentment and relaxation in humans too. Except, perhaps, when it is at 3 am…