Everybody loves the sound of a cat purring. It’s mesmerizing and satisfying all at the same time. There’s nothing like curling up in bed on a cold day with your cat and hearing those soft, thrumming vibrations. But what causes a cat to purr? And why do they do it? Read below to find out some of the explanations people have given for cats’ purring through the ages, and what scientists believe causes it today.
What People Thought Made Cats Purr in the Past
Five hundred years ago in England, the purring made by a cat was believed to be a secret form of communication with evil spirits. Over the years, as more cats became domesticated, the opinion changed to purring being a form of snoring a cat did when it was content.
Now we know that purring is not always indicative of feline happiness. Cats can do it when they feel threatened or even fearful. Sometimes the explanation vets give for a cat’s purring during a visit is nervousness – like when human’s smile when they are nervous.
Purring vs. Roaring
It has been proven by some brave animal behaviorists that cats that roar aren’t able to purr, and cats that purr cannot roar. During evolution, the lion’s throat structure remained flexible so that they could communicate with roars. Their larynxes aren’t stiff enough to allow the purring sound.
Roaring is far more important to a predator cat that has to protect its territory and compete with scavengers for prey. Predator cats live in packs, so they need to be able to communicate with each other from far distances. A domestic cat operates as a loner and has no need to communicate with any other one of its species. Also in the non-roaring category are animals such as raccoons, hyenas, and even guinea pigs.
Now for the Science Bit
The urge to purr begins in a cat’s brain. That’s where a structure called the neural oscillator is located. It sends a repetitive message to the laryngeal muscles, and they respond by twitching whenever the cat breathes in and out. It’s the twitching action that causes the vocal cords to vibrate whenever the cat inhales and exhales.
Scientists have also discovered that there is a hidden soundwave hidden inside a purr’s oscillation that triggers the nurturing instinct in humans. There is an inherent need in us to respond to these frequencies as we would to a baby’s cry. When we hear a cat’s purr, it also has the effect of lowering our blood pressure and stress levels.
Purring is good for the cat too. Besides making its life super-comfortable by getting humans to do their bidding, the vibrations produced by purring can also help the cat’s body heal itself faster, mend torn muscles, and even reduce swelling and pain.
Next time you hear your furry friend purring away on the couch, you now know it’s more than just happiness.