Yes, that’s the perennial question, and of course it depends on what you mean by “smarter”. Several people (mostly dog owners, of course) have sent me articles touting a recent finding that dogs are smarter than cats because they have more neurons in their brains. For example, this article reports a new article in Frontiers in Neuroanatomy (reference and free abstract at bottom; I haven’t read it as it hasn’t been published beyond the abstract).
“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,” says neuroscientist Suzana Herculano-Houzel from Vanderbilt University in the US.
Past studies have compared the ‘neural packing density’ in the brains of our favourite carnivorous pets, estimating that cats have about 300 million neurons, roughly doubling the 160 million of dogs.
But now it seems we might have been a little hasty handing the trophy to cats.
The team looked at eight different meat-eating animals, analysing one or two representative specimens of ferret, mongoose, raccoon, cat, dog, hyena, lion, and brown bear.
Based on their results, dogs have closer to 530 million neurons, compared to the 250 million of cats.
What’s more, dogs had the most neurons of any carnivore, even though they didn’t have the largest brains.
Sorry, but this is complete nonsense. Barring data showing that neuronal number has a very tight correlation with intelligence, barring widely accepted definitions of animal “intelligence”, and barring “intelligence tests” on a diversity of species, all we know is what the paper reports: dogs have more neurons in their brains than do cats. And there could be reasons for that beyond intelligence, like, perhaps, olfaction.
The real way to see which animal is smarter is to devise some test that comports with your definition of animal intelligence, and then apply it to the species in which you’re interested. You also have to be sure that the animal can be trained to take a test—and we know about training of cats versus dogs.
The kicker here, which throws all this garbage out the window, is in the very article above:
The real oddball carnivore is the racoon [sic; these people can’t even spellcheck] – even though it’s close to cats in terms of size, it actually has a similar number of neurons to dogs. Considering raccoons can smash intelligence tests, we’re not surprised.
Racoons >> dogs even though they have the same number of neurons. Sorry, but I’m not impressed with neuron count.
And here’s another bit of evidence: watch the video below. The “smart” dog can’t figure out to turn the stick sideways. And realize that a cat wouldn’t even pick up a damn stick to please somebody else. Now who’s smarter?
Alvargenga, D. J. et al. 2017. Dogs have the most neurons, though not the largest brain: Trade-off between body mass and number of neurons in the cerebral cortex of large carnivoran species. Frontiers Neuroanatomy, in press. doi: 10.3389/fnana.2017.00118