Cats are often characterized as aloof, evil masterminds in children’s movies, but new research has put a spin on the age-old debate about whether dogs or cats are the smarter of the household pets. According to a new study from scientists at Vanderbilt University, scientists have proven dogs are way "brainier" than cats — but does that mean they're smarter?
The study, which is forthcoming from the journal Frontiers in Neuroanatomy, analyzed the brains from different domesticated and feral carnivores, including ferrets, mongoose, raccoons, cats, dogs, hyenas, lions and brown bears. Suzana Herculano-Houzel, an Associate Professor of Psychology and Biological Sciences, and co-author of the study, said the researchers “were interested in comparing different species of carnivorans to see how the numbers of neurons in their brains relate to the size of their brains.” To do that, scientists actually counted the cortical neurons — aka, the cells in your cerebral cortex that enable complex thought, voluntary movement, perception, and well, overall intelligence — for the first time ever before in a study. Herculano-Houzel said in a press release she believes the number of neurons an animal has “determines the richness of their internal mental state, and their ability to predict what is about to happen in their environment based on past experience.”
The researchers discovered that cats possess around 250 million cortical neurons, but dogs had about 530 million cortical neurons — surpassing your feline friend by a long shot. “I'm 100 percent a dog person,” Herculano-Houzel explained, “But, with that disclaimer, our findings mean to me that dogs have the biological capability of doing much more complex and flexible things with their lives than cats can." In comparison to our furry companions, human beings have around 16 billion of these same cortical neurons. So, while the hundreds of millions may seem like a lot of these brain cells, it’s only a fraction of what highly intelligent animals are believed to have. This, however, does not necessarily mean that one species is smarter — just that one may be able to do more complex things.
The Vanderbilt University study revealed some interesting discoveries about wild animals that challenge commonly-held misbeliefs in the scientific community. For example, the researchers determined that small and medium-sized carnivores had around the same amount of neurons as their prey (herbivores), when it was previously thought that “hunting” animals were brainier than the animals being hunted. However, large predators were found to actually have less neurons in ratio to their brain size. Additionally, there was no remarkable difference in brain size between our domesticated pets and their distant, wild cousins. One exception the study found were raccoons, who Herculano-Houzel described as “not your typical carnivoran” because they have “a fairly small brain, but they have as many neurons as you would expect to find in a primate.” Raccoons have brains the size of cats, but pack the same cortical neuron count as dogs.
This study also carries ethical weight, and may make you question the way humans treat other intelligent animals with high cortical neuron counts, such as primates, dolphins, and whales. Even elephants have around 3 billion cortical neurons, possessing a wide-range of cognitive ability, complex thoughts, and emotional intelligence. Yet, they have been routinely targeted by poachers, hunted as trophies, and abused.
All-in-all, this study reveals both domesticated and wild animals are much more complex and unique than scientists understood. "Diversity is enormous. Not every species is made the same way,” said Herculano-Houzel on studying the brains of animals. “Yes, there are recognizable patterns, but there are multiple ways that nature has found of putting brains together — and we're trying to figure out what difference that makes." Though much research is left to be done around all the different species of animals, this study gives dog people a scientific advantage when arguing with cat lovers about which animal is better. Your feline friend may be your favorite, but they are nowhere near as brainy as dogs.