There are certain things in this world that divide us. There are morning people and there are night people. There are coffee people and there are tea people. And perhaps the greatest dividing line of all is the one between dog people and cat people. But why does that divide exist? Cats and dogs are both cute and fluffy and amazing in their own ways. Why, then, are people so firm in taking a stance between the two? To answer that eternal question, we must turn to science.
The science behind why humans love dogs
For dog parents, there's an inherent, undeniable truth to the label "man's best friend." For dog people, the bond between pups and humans feels natural and right. But why is that? Well, for one thing, the relationship between humans and dogs goes way back—at least 14,000 years back, to be precise.
In that time, dogs and humans have developed a shared language that seems to impress scientists more and more the more it's studied. According to a study published in Animal Cognition, dogs can actually smell our emotional states. Stanley Coren, Ph.D., DSc, FRSC, suggested, "dogs do seem to be able to smell our emotional state, and they then seem to trust our responses to the situation by adopting those emotional states as their own." Recent research from the Department of Veterinary Medicine at the University of Bari Aldo Moro in southern Italy found that dogs also seem to be able to hear difference in our emotions.
But does understanding us mean that dogs love us? The skeptics of the world might argue that dogs are just leveraging their ability to read us to get things they want or need (like food and shelter and treats and toys) and that it's a stretch to assume that they really love us back.
Over the years, scientists have designed a range of experiments aimed at answering the question: Do our dogs really love us. In one experiment conducted by Clive Wynne, a psychologist and founder of the Canine Science Collaboratory at Arizona State University, dogs and their owners were placed in a room together and the owners climbed into a box and proceeded to make distress noises (crying, whimpering, etc.). The researchers found that, in the initial experiment, a third of dogs opened the box to "rescue" their owner and that nearly every dog in the experiment exhibited clear signs of sadness when their owners were stuck and in distress. In a followup run of the experiment, the researchers began by training the dogs how to open the box before moving on to having their owners climb inside and feign distress. When the dogs had been taught how to open the box beforehand, pretty much every single one "rescued" their owners, suggesting that, in the first experiment, confusion and feelings of helplessness on the dogs' part were the primary factors that stopped them from trying to save their human.
And, on an even more measurable level, some studies have found that oxytocin, also known as the "love hormone" because it gives us warm-fuzzies and is released during moments of social bonding and physical affection, is released in greater amounts by both humans and dogs when we interact. Translation: Cuddling with your dog isn't just proven to make you feel good—it's also proven to make him feel good too.
The science behind why humans love cats
Team Cats has plenty of evidence to back up cat parents' bonds with their four-legged friends, too, though. When it comes to pure numbers, cats reign supreme as the world's most popular pet and the cat/human relationship can be traced back between 10,000 and 15,000 years, with DNA evidence placing the first appearance of the pet cat's ancestor, the Arabian wildcat Felis silvestris lybica, somewhere in that timeframe.
Although the fact that cats actually domesticated themselves has led some to assume that their relationship with humans is more give than take, there's plenty of scientific evidence that cats don't just pretend to love humans because they feed them. In one study conducted by researchers at Oregon State University, over half (52 percent) of the cats involved in the project chose human company above toys, food or intriguing smells (like gerbils and catnip). What's more, Ainsworth Strange Situation Tests done on cats have shown that they clearly preferred their owners over someone they did not know.
Cats (kittens in particular) also have neuroscience on their side when it comes to courting human love. The human brain is wired to want to protect and love on cute things as a way to make sure we take care of our own babies. Kittens, it turns out, are cute enough to trigger the same response the brain has to human babies, leaving us inclined to love and want to care for little kitties.
And the awws that cats and kittens elicit are good for our mental health, too. In a study published in the journal Computers in Human Behavior, researchers found that just watching videos of cats online lowers stress levels.
What science says about the difference between dog people and cat people
Since pet owners on both sides of the debate have science backing up their love, that leaves us to wonder: What does science have to say about the differences between dog lovers and cat lovers? Is there a personality trait (or several personality traits) that set the groups apart?
In a study conducted by researchers at the University of Florida, participants were given a personality test as well as a test to determine their preferences for dogs versus cats, with people who identified as liking both dogs and cats (or to disliking both animals) being eliminated from the final findings. The study found that dog people were, on the whole, more extroverted and outgoing with richer social lives and that dog lovers were more likely to be "tough-minded"—meaning that they tended to focus more on situations than emotions.
In their analysis of the results, the researchers wrote, "Taken together, these findings describe the personalities of the average cat person as shy, solitary, impersonal, serious, and nonconformist, but also creative, sentimental, independent, and self-sufficient. Conversely, these findings describe dog people as grounded, pragmatic, and dutiful, as well as warm, outgoing, sociable, expressive, and group oriented."
A 2010 study compared 4,565 participants' self-reported preferences for dogs or cats with their results in the Big Five Inventory and found that dog people rated higher on Extraversion, Agreeableness, and Conscientiousness, but lower on Neuroticism and Openness than did cat people. Furthermore, the study found that these differences still held true when controlling for sex differences in pet-ownership rates.
Some differences between dog people and cat people are self-reported. In one recent survey, dog owners were more likely to describe themselves as fun to be with, while cat owners were more likely to describe themselves as dependable and emotionally sensitive. For what it's worth, fish owners described themselves as being the happiest and reptile owners reported being the most independent.
According to some researchers, the differences between cat and dog people is likely a combination of innate qualities and those self-reported preferences and ideals. Denise Guastello, an associate professor of psychology at Carroll University in Waukesha, Wisconsin, who presented the findings of a study she worked on at an Association for Psychological Science meeting in 2014, says people may gravitate toward pets that fit the vision they have of themselves or the lifestyle they want to lead.
"It makes sense that a dog person is going to be more lively, because they're going to want to be out there, outside, talking to people, bringing their dog," Guastello said. "Whereas, if you're more introverted, and sensitive, maybe you're more at home reading a book, and your cat doesn't need to go outside for a walk."
Whether you're a cat person or a dog person, there is plenty of science to back up your undying affections. This is definitely one divide where there is no such thing as a wrong choice.