Guess which one!
The answer is found here: https://www.nationalgeographic.com/animals/article/dog-cat-b...
Great apes are smarter than small apes. Big birds are generally smarter than small birds. Elephants are smarter than deer.
Well said. Here's another expression I often use: Stupider than Jupiter!
Jupiter is big but not very intelligent as far as we know.
You can't necessarily compare bird brains to whale brains, but within birds (or really any similar class of animal) neurons seems to directly correlate with perceived intelligence.
You can teach your cat to use the toilet, come when you call its name, roll and jump. They can even open doors which requires understanding how a door knob/rail system behaves. We had a cat that would follow us everywhere even if we went for a walk outside the house for several miles.
Additionally, cats are not nurtured like puppies are. There are considerable amounts of information and know-how from breeders on how to socialize puppies to develop their ability to follow instructions and respect their master. Kittens on the other hand are mostly raised in small cages in pet shops and treated as glorified hamsters that can jump high and purr. Going further, canines are pack animals which are naturally predisposed to work with others and understand complex hierarchies. Felines are mostly solitary and only really get in groups during mating season.
Another counter-example (unrelated to cats) are birds. Birds are incredibly intelligent, they can learn to solve puzzles, talk, and answer to their name. Yet if you ever get a budgie (or similar) you'll notice that your animal seems dumb as a rock. That's because birds require a lot of work in order to learn those tricks because they are naturally distrustful of humans. If you put ~1hr a day on training your budgie as you would with a young pup, you would see incredible improvements.
As a final note, I would concede that a cat's intellect is no match to a dog's, but using "follow instructions" as a metric to define intelligence and concluding "cat are dumb" is an oversimplification.
There are animal handlers and zookeepers who have trained cats to perform complex tasks on obstacle courses repeatedly & reliably, just like dogs and other animals. I saw this first hand at a zoo myself (I think it was San Diego but I'm not positive).
On top of all this, if you have interacted with a lot of cats, it becomes obvious that there is a ton of diversity in their personalities & behavioral patterns, even between siblings. There is no point in discussing 'smarter or dumber' here, their intelligence is just different-- it's unique to their species, as with pretty much every other animal capable of being trained.
With that in mind, dolphins have 2x and elephants have 3x the number of neurons as humans.