Which Species Has the Brains? Dogs or Cats?
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The world can mostly be divided into two groups of humans: dog people and cat people. And when asked which species is the smarter of the two, our answer is probably dictated by nothing other than which animal we have a greater affection for.
Of course, there are many ways that cognition, aptitude, intelligence, or any other way you want to put it can be tested among domesticated and wild animals alike, and almost any species can and will outperform another based on which test they are given. In reality, almost any test of intelligence is really only going to measure an animal’s aptitude in a specific skill as needed throughout their species’ evolution. Dogs have a sense of smell superior to our own, for example, but then again, pigs may have an even stronger sense of smell than them. And according to authors Stephen E. G. Lea and Britta Osthaus, dogs aren’t exactly “geniuses,” or at least exceptionally intelligent when compared to some species when it comes to their communication skills with people. Can dogs learn and be aware of hand signals and auditory cues from humans? Yes, but as the authors pointed out, this is in no way unique to the species. “The reigning champions of the ability to follow human hand signals are the bottlenose dolphin and the grey seal,” the authors said. In fact, the research pointed out that “social cognition” is the domain we actually have the greatest amount of information on when it comes to dogs and their intelligence. “Dogs perform as well as or better than other domestic animals on social learning tests. As regards tests inspired by theory-of-mind considerations (perspective taking, deception, and empathy), we have too little comparative data to draw any conclusions. In experiments carried out so far, chimpanzees are more likely than dogs to solve tasks requiring perspective-taking, though the evidence base for dogs’ perspective-taking is improving, and dogs may do better than chimpanzees in cooperative situations.“
“Dog cognition may not be exceptional, but dogs are certainly exceptional cognitive research subjects,” they wrote. “Our knowledge of nonhumans’ understanding of pointing, gaze, and other human signals has been greatly expanded through studies on dogs. There are several fields of cognition—empathy, for example—where almost our only nonprimate evidence comes from dogs, and the number of these seems likely to grow because the cooperativeness of dogs means that more complex research designs can be carried through than could be contemplated with less obliging subjects (e.g., cats). And although dogs may not be typical carnivorans, or typical social hunters, or typical domestic animals, what we know about cognition in all those groups consists to a substantial extent of what we know about dog cognition.”
And this brings us right back to the centuries-old dogs versus cats debate. Which of the two is actually smarter? Can that determination actually be made? According to researchers, one significant measure shows that dogs actually have a hefty leg up on many hunting species, especially cats: sheer brainpower. The team of researchers analyzed the physical brains, not through scans or measuring brain activity during specific stimulation, but by actually examining their physical properties and makeup. If neurons — the most basic building block of the nervous system — offer a reliable measure of intelligence, a dog’s remarkably dense cerebral cortex makes them virtual geniuses in the field of hunting species. The demands of hunting, the researchers theorize, require a higher count of cortical neurons and therefore a greater expanse of actual brainpower.
The study couldn’t simply conclude that the overall size of a brain dictates a species’ intelligence, rather the final measure comes from taking into account its size relative to the animal’s body just for starters. This is known as the encephalization quotient, which then led researchers to also discover the anatomy of each species’ brain, and finally, the number of cells within them. It’s a similar idea to account for the processing power of a computer.
"I believe the absolute number of neurons an animal has, especially in the cerebral cortex, 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," said neuroscientist Suzana Herculano-Houzel from Vanderbilt University.
By this measure, the final count of neurons at the disposal of our four-legged friends is impressive. Past studies suggested that cats possess about 300 million neurons while dogs have about 160 million. When the new research looked at eight different meat-eating hunters — ferret, mongoose, raccoon, cat, dog, hyena, lion, and brown bear — they actually found this time that dogs have closer to 530 million neurons to the 250 million of cats. In fact, dogs have the most neurons of all the carnivores studied. Larger meat-eating species, they found, have relatively fewer neurons for their overall size. Brown bears, for example, are 10 times as big as cats but both animals have the same number of cortical neurons, according to the researchers.
"Meat eating is largely considered a problem-solver in terms of energy, but, in retrospect, it is clear that carnivory must impose a delicate balance between how much brain and body a species can afford," says Herculano-Houzel.
This measure simply reinforces a logical idea that being bigger, stronger, and likely faster negates the need to be smarter when it comes to chasing down prey.
"I'm 100 percent a dog person," Herculano-Houzel says, "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."
So it may not be the end all be all of another never-ending dog versus cat debate but it’s certainly an interesting bit of insight into the differences between two of our favorite domesticated animals. Dogs, as it turns out, have a bit more brainpower than one might guess. Whether or not they put it all to use, or even need to, is another question altogether.
