Why Cats Purr
Your cat’s purr can mean many different things. Find out what she’s trying to tell you.
Purr-suasive Purrs continued...
Karen McComb, PhD, who headed the study, decided to explore the unique characteristics of these insistent purrs after wondering why her own cat could be so annoying. In the study, recordings of 10 cats’ purrs revealed that cats sometimes develop a “twist on purring.”
Cats add a vocalization into the mix to solicit responses from humans, Hart says. “Added to the basic 25 Hz purr is an overlay of a high-frequency cry-meow that humans perceive as somewhat obnoxious,” he says. “Cats apparently learn to do this to get people to feed them sooner.”
This solicitation purr seems to develop more often in quiet households where cats have a one-on-one relationship with a human, and the purr is less likely to be overlooked. But even people with no cat experience perceived this special purr as more urgent and less pleasant. McComb's team suggests that cats may have learned how to tap into a mammalian response for nurturing offspring by embedding a cry within a call that’s normally associated with contentment.
“I wonder if what we’ve done is to select pet cats to give us signals that they need us,” says Overall, author of Clinical Behavioral Medicine for Small Animals.
Healing Powers of the Purr?
Cats appear to purr for a host of other reasons as well. They purr when in pain or in labor, when ill or injured, or even when near death. Kittens also purr soon after birth. What could account for all this energy expenditure - especially during times of vulnerability? Could it be there’s a significant survival advantage?
Researcher Elizabeth von Muggenthaler of the Fauna Communications Research Institute in North Carolina (FCRI) is a specialist in the field of bioacoustics. This is the study of the frequency, pitch, loudness, and duration of animal sounds related to their behavior. She was one of the first to pull several strands of research together, and propose that felines do gain evolutionary healing advantages from the purr.
Many experts theorize that the 25 Hz frequency of the cat’s purr might offer a kind of built-in physical therapy. It’s probably no accident that this frequency is also used in humans to help wounds heal faster, Hart says.
Good Vibrations - For Humans, Too
Cats have overtaken dogs as the number one pet in the U.S., where 60% of homes have at least one pet, says Rebecca Johnson, PhD, RN, FAAN, director of the Research Center for Human Animal Interaction. Maybe one reason is because cats do a better job of lowering stress and blood pressure than many other pets, and purring may help with that.
“Purring is an auditory stimulus that people attribute to peacefulness and calmness," Johnson says. Whether right or wrong, we generally construe it as something positive. “That gives us positive reinforcement for what we’re doing and can contribute to the whole relaxation effect when we interact with our cats.”
And that’s a pretty sweet deal for a simple stroke of a feline’s fur.