Why Dogs Are Smarter Than Cats: Science Shows They Pack More Neurons in Their Brains

In the dogs v. cats debate, dogs may have just earned a point. New research suggests that canines have more neurons in the cerebral cortex of their brains than their feline counterparts.

Scientists obtained brains from a wide variety of animals in the same taxonomic order, "carnivora," which mostly consists of carnivores. They chose carnivores because they thought predators would have to be smarter than prey, because there are a variety of sizes among them, and there are both wild and domestic carnivores. The researchers studied cats, dogs, bears, raccoons, mongooses, lions and hyenas.

What they found surprised them.

A puppy rests in the grass in Danville, California. Kristin Hugo

According to the paper, bigger animals didn't necessarily have more neurons. Bears, for instance, have brains 10 times the size of cat brains, yet approximately the same number of neurons. The bear brain has 10 times as many non-neuron cells than the cat does, though. The research was published in Frontiers of Neuroanatomy.

Another surprising finding was that the carnivores don't tend to have more neurons than herbivores. The researchers had presumed that an animal who stalks and takes down their prey would have to outsmart that animal. But when compared to similar research on herbivores, both predators and the preyed-upon appeared to share a similar number of neurons.

And, perhaps most relevant to pet owners, the researchers found that dogs have more neurons than cats, or even hyenas, which have much larger brains than dogs. Hyenas are, in fact, more closely related to cats than dogs. Specifically, dogs have roughly 530 million neurons, while cats have about 250 million, according to the study. Humans, by contrast, have about 16 billion each.

Does this mean that dogs are smarter than cats? It's hard to say. Measuring animal intelligence is a complicated endeavor. A bigger brain could suggest an animal is smarter, but that would make whales smarter than people. There is also the brain-to-body-size ratio to consider. Counting neurons is one way to estimate an animal's intelligence, but research says that even very tiny brains with few neurons can be incredibly complex.

Understanding the intelligence of animals takes lots of research in addition to knowing the number of neurons that they possess. There is an entire journal of Animal Behavior and Cognition that includes volumes of research on the topic.

However, setting aside the dog-cat debate, dogs do appear to have a special kind of intelligence, as well as a unique relationship to humans. Dogs can be trained to guide the blind, sniff out explosives at airports, and perform tricks on command much more easily than cats.

Notably, however, the research showed that raccoons have as many neurons as primates—so maybe we should consider using guide-raccoons too.